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Capacitors and Dielectrics — JEE Previous Year Questions

Every Capacitors and Dielectrics question asked in JEE Main and JEE Advanced across the last 186 papers — 134 questions, each with its correct answer. Free to read, no account needed.

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All 134 Capacitors and Dielectrics questions

Most recent papers first.

Q1·PhysicsNumericalJEE Advanced 2026
Passage: A container of height 2 m, length 2 m and breadth 1 m is made of insulating vertical walls and two large area horizontal metal plates (M1M_{1}M1​ and M2M_{2}M2​) which extend far beyond the vertical walls in all directions. The container is partitioned into two equal chambers with a thin insulating vertical wall. The partition wall contains a small hole of cross-sectional area 10\sqrt{10}10​ cm2^{2}2 near its bottom edge. Initially the hole is closed and the left chamber of the container is completely filled with a liquid of dielectric constant ϵr=15\epsilon_{r} = 15ϵr​=15 and the right chamber is empty (ϵr=1\epsilon_{r} = 1ϵr​=1). At time t=0t = 0t=0, the hole is opened and the liquid flows from the left chamber to the right chamber. In both the chambers, the space above the liquid has ϵr=1\epsilon_{r} = 1ϵr​=1 and is maintained at atmospheric pressure. The schematic of the container at a time t>0t > 0t>0 is shown in the figure. [Given: acceleration due to gravity is 10 ms−2^{-2}−2.] Question: The difference in the capacitance (in F) between the metal plates at t=0t = 0t=0 and that at t=500t = 500t=500 s is (8−n)ϵ0(8 - n)\epsilon_{0}(8−n)ϵ0​, where ϵ0\epsilon_{0}ϵ0​ is the permittivity of free space. The value of nnn is:

Correct answer: 1.97

Step-by-step solution →
Q2·PhysicsNumericalJEE Main 2026
A parallel plate capacitor is having separation between plates 0.885 mm. It has a capacitance of 1 μ1\,\mu1μF when the space between the plates is filled with an insulating material of resistivity 1×10131\times 10^{13}1×1013 Ω\OmegaΩm and resistance 17.7×101417.7\times 10^{14}17.7×1014 Ω\OmegaΩ. Relative permittivity of the insulating material is α×107\alpha \times 10^{7}α×107. The value of α\alphaα is ________. (Take permittivity of free space =8.85×10−12= 8.85\times 10^{-12}=8.85×10−12 F/m)

Correct answer: 2

Step-by-step solution →
Q3·PhysicsSingle correctJEE Main 2026
A sphere of capacitance 100 pF is charged to a potential of 100 V. Another identical uncharged metal sphere is brought in contact with the charged sphere, then the change in the total energy stored on these spheres, when they touch is α×10−7\alpha \times 10^{-7}α×10−7 J. The value of α\alphaα is __________. (combined capacitance of spheres is 200 pF)
  1. (A)5
  2. (B)52\frac{5}{2}25​
  3. (C)72\frac{7}{2}27​
  4. (D)92\frac{9}{2}29​

Correct answer: (B)

Step-by-step solution →
Q4·PhysicsSingle correctJEE Main 2026
A parallel plate air capacitor is connected to a battery. The plates are pulled apart at uniform speed vvv. If xxx is the separation between the plates at any instant, then the time rate of change of electrostatic energy of the capacitor is proportional to xαx^{\alpha}xα, where α\alphaα is ______.
  1. (A)−2-2−2
  2. (B)111
  3. (C)−1-1−1
  4. (D)222

Correct answer: (A)

Step-by-step solution →
Q5·PhysicsSingle correctJEE Main 2026
From the circuit given below, the capacitance between terminals AAA and BBB shown in the circuit is ______ μF. (take C1=C2=C3=1C_{1} = C_{2} = C_{3} = 1C1​=C2​=C3​=1 μF and C4=2C_{4} = 2C4​=2 μF.)
  1. (A)2
  2. (B)7/2
  3. (C)7/3
  4. (D)5/2

Correct answer: (A)

Step-by-step solution →
Q6·PhysicsSingle correctJEE Main 2026
A parallel plate air capacitor has a capacitance CCC. When it is half filled as show in figure with a dielectric constant K=5K = 5K=5, the percentage increase in the capacitance is ______.
  1. (A)33.34
  2. (B)66.67
  3. (C)200
  4. (D)400

Correct answer: (B)

Step-by-step solution →
Q7·PhysicsSingle correctJEE Main 2026
Identify the correct statements : A. Effective capacitance of a series combination of capacitors is always smaller than the smallest capacitance of the capacitor in the combination. B. When a dielectric medium is placed between the charged plates of a capacitor, displacement of charges cannot occur due to insulation property of dielectric. C. Increasing of area of capacitor plate or decreasing of thickness of dielectric is an alternate method to increase the capacitance. D. For a point charge, concentric spherical shells centered at the location of the charge are equipotential surfaces. Choose the correct answer from the options given below.
  1. (A)A, B and C only
  2. (B)C and D only
  3. (C)A, C and D only
  4. (D)B and D only

Correct answer: (C)

Step-by-step solution →
Q8·PhysicsSingle correctJEE Main 2026
Three parallel plate capacitors each with area A and separation d are filled with two dielectric (k1k_1k1​ and k2k_2k2​) in the following fashion. Which of the following is true? (k1>k2k_1 > k_2k1​>k2​)
  1. (A)CB>CC>CAC_B > C_C > C_ACB​>CC​>CA​
  2. (B)CC>CB>CAC_C > C_B > C_ACC​>CB​>CA​
  3. (C)CC>CA>CBC_C > C_A > C_BCC​>CA​>CB​
  4. (D)CA>CC>CBC_A > C_C > C_BCA​>CC​>CB​

Correct answer: (D)

Step-by-step solution →
Q9·PhysicsSingle correctJEE Main 2026
A parallel plate capacitor with plate separation 5 mm is charged by a battery. On introducing a mica sheet of 2 mm and maintaining the connections of the plates with the terminals of the battery, it is found that it draws 25% more charge from the battery. The dielectric constant of mica is____.
  1. (A)2.5
  2. (B)2.0
  3. (C)1.5
  4. (D)1.0

Correct answer: (B)

Step-by-step solution →
Q10·PhysicsNumericalJEE Main 2026
The space between the plates of a parallel-plate capacitor of capacitance C (without any dielectric) is now filled with three dielectric slabs of dielectric constants K1=2K_1 = 2K1​=2, K2=3K_2 = 3K2​=3, and K3=5K_3 = 5K3​=5 (as shown in the figure). If new capacitance is n3C\frac{n}{3}C3n​C then the value of n is ______.

Correct answer: 8

Step-by-step solution →
Q11·PhysicsNumericalJEE Main 2026
A capacitor PPP with capacitance 10×10−610 \times 10^{-6}10×10−6 F is fully charged with a potential difference of 6.0 V and disconnected from the battery. The charged capacitor PPP is connected across another capacitor QQQ with capacitance 20×10−620 \times 10^{-6}20×10−6 F. The charge on capacitor QQQ when equilibrium is established will be α×10−5\alpha \times 10^{-5}α×10−5 C (assume capacitor QQQ does not have any charge initially), the value of α\alphaα is ________ .

Correct answer: 4

Step-by-step solution →
Q12·PhysicsSingle correctJEE Main 2026
A parallel plate capacitor has capacitance C, when there is vacuum within the parallel plates. A sheet having thickness (13)rd\left(\frac{1}{3}\right)^{\mathrm{rd}}(31​)rd of the separation between the plates and relative permittivity K is introduced between the plates. The new capacitance of the system is :
  1. (A)3KC2K+1\frac{3KC}{2K+1}2K+13KC​
  2. (B)CK2+K\frac{CK}{2+K}2+KCK​
  3. (C)3CK2(2K+1)2\frac{3CK^{2}}{(2K+1)^{2}}(2K+1)23CK2​
  4. (D)4KC3K−1\frac{4KC}{3K-1}3K−14KC​

Correct answer: (A)

Step-by-step solution →
Q13·PhysicsIntegerJEE Main 2025
Space between the plates of a parallel plate capacitor of plate area 4 cm24\ cm^24 cm2 and separation of (d) 1.77 mm, is filled with uniform dielectric materials with dielectric constants (3 and 5) as shown in figure. Another capacitor of capacitance 7.5 pF is connected in parallel with it. The effective capacitance of this combination is ___ pF. (Given ε0=8.85×10−12\varepsilon_0=8.85\times10^{-12}ε0​=8.85×10−12 F/m)

Correct answer: 15

Step-by-step solution →
Q14·PhysicsIntegerJEE Main 2025
A parallel plate capacitor has charge 5×10−85\times10^{-8}5×10−8 C. A dielectric slab is inserted between the plates and almost fills the space between the plates. If the induced charge on one face of the slab is 4×10−84\times10^{-8}4×10−8 C then the dielectric constant of the slab is __________.

Correct answer: 5

Step-by-step solution →
Q15·PhysicsIntegerJEE Main 2025
Four capacitor each of capacitance 16 μ\muμF are connected as shown in the figure. The capacitance between points A and B is ______ (in μ\muμF).

Correct answer: 64

Step-by-step solution →
Q16·PhysicsSingle correctJEE Main 2025
Three parallel plate capacitors C1C_1C1​, C2C_2C2​ and C3C_3C3​ each of capacitance 5 μ\muμF are connected as shown in the figure. The effective capacitance between points A and B, when the space between the parallel plates of C1C_1C1​ capacitor is filled with a dielectric medium having dielectric constant of 4, is:
  1. (A)22.5 μF22.5\ \mu F22.5 μF
  2. (B)7.5 μF7.5\ \mu F7.5 μF
  3. (C)9 μF9\ \mu F9 μF
  4. (D)30 μF30\ \mu F30 μF

Correct answer: (C)

Step-by-step solution →
Q17·PhysicsSingle correctJEE Main 2025
Using a battery, a 100 pF capacitor is charged to 60 V and then the battery is removed. After that, a second uncharged capacitor is connected to the first capacitor in parallel. If the final voltage across the second capacitor is 20 V, its capacitance is: (in pF)
  1. (A)600
  2. (B)200
  3. (C)400
  4. (D)100

Correct answer: (B)

Step-by-step solution →
Q18·PhysicsSingle correctJEE Main 2025
A parallel plate capacitor is filled equally (half) with two dielectrics of dielectric constant ε1\varepsilon_1ε1​ and ε2\varepsilon_2ε2​, as shown in the figures. The distance between the plates is ddd and area of each plate is AAA. If the capacitances in the first configuration and the second configuration are C1C_1C1​ and C2C_2C2​ respectively, then C1C2\dfrac{C_1}{C_2}C2​C1​​ is:
  1. (A)ε1ε22(ε1+ε2)2\dfrac{\varepsilon_1\varepsilon_2^2}{(\varepsilon_1+\varepsilon_2)^2}(ε1​+ε2​)2ε1​ε22​​
  2. (B)4ε1ε2(ε1+ε2)2\dfrac{4\varepsilon_1\varepsilon_2}{(\varepsilon_1+\varepsilon_2)^2}(ε1​+ε2​)24ε1​ε2​​
  3. (C)ε1ε2ε1+ε2\dfrac{\varepsilon_1\varepsilon_2}{\varepsilon_1+\varepsilon_2}ε1​+ε2​ε1​ε2​​
  4. (D)ε0(ε1+ε2)2\dfrac{\varepsilon_0(\varepsilon_1+\varepsilon_2)}{2}2ε0​(ε1​+ε2​)​

Correct answer: (B)

Step-by-step solution →
Q19·PhysicsSingle correctJEE Main 2025
A capacitor, C1=6 μFC_1=6\ \mu FC1​=6 μF is charged to a potential difference of V0=5V_0=5V0​=5 V using a 5 V battery. The battery is removed and another capacitor, C2=12 μFC_2=12\ \mu FC2​=12 μF is inserted in place of the battery. When the switch ‘S’ is closed, the charge flows between the capacitors for some time until equilibrium condition is reached. What are the charges (q1q_1q1​ and q2q_2q2​) on the capacitors C1C_1C1​ and C2C_2C2​ when equilibrium condition is reached.
  1. (A)q1=15 μC,q2=30 μCq_1=15\ \mu C, q_2=30\ \mu Cq1​=15 μC,q2​=30 μC
  2. (B)q1=30 μC,q2=15 μCq_1=30\ \mu C, q_2=15\ \mu Cq1​=30 μC,q2​=15 μC
  3. (C)q1=10 μC,q2=20 μCq_1=10\ \mu C, q_2=20\ \mu Cq1​=10 μC,q2​=20 μC
  4. (D)q1=20 μC,q2=10 μCq_1=20\ \mu C, q_2=10\ \mu Cq1​=20 μC,q2​=10 μC

Correct answer: (C)

Step-by-step solution →
Q20·PhysicsIntegerJEE Main 2025
A parallel plate capacitor consisting of two circular plates of radius 10 cm is being charged by a constant current of 0.15 A. If the rate of change of potential difference between the plates is 7×1087\times 10^87×108 V/s then the integer value of the distance between the parallel plates is ______ μm. (Take ε0=9×10−12\varepsilon_0=9\times 10^{-12}ε0​=9×10−12 F/m, π=227\pi=\dfrac{22}{7}π=722​.)

Correct answer: 1320

Step-by-step solution →
Q21·PhysicsSingle correctJEE Main 2025
A parallel plate capacitor of capacitance 1 μ\muμF is charged to a potential difference of 20 V. The distance between plates is 1 μ\muμm. The energy density between plates of capacitor is:
  1. (A)1.8×1031.8\times10^31.8×103 J/m3^33
  2. (B)2×10−42\times10^{-4}2×10−4 J/m3^33
  3. (C)2×1022\times10^22×102 J/m3^33
  4. (D)1.8×1051.8\times10^51.8×105 J/m3^33

Correct answer: (A)

Step-by-step solution →
Q22·PhysicsSingle correctJEE Main 2025
Two capacitors C1C_1C1​ and C2C_2C2​ are connected in parallel to a battery. Charge-time graph is shown below for the two capacitors. The energy stored with them are U1U_1U1​ and U2U_2U2​, respectively. Which of the given statements is true?
  1. (A)C1>C2C_1>C_2C1​>C2​, U1>U2U_1>U_2U1​>U2​
  2. (B)C2>C1C_2>C_1C2​>C1​, U2<U1U_2<U_1U2​<U1​
  3. (C)C1>C2C_1>C_2C1​>C2​, U1<U2U_1<U_2U1​<U2​
  4. (D)C2>C1C_2>C_1C2​>C1​, U2>U1U_2>U_1U2​>U1​

Correct answer: (D)

Step-by-step solution →
Q23·PhysicsSingle correctJEE Main 2025
A parallel plate capacitor was made with two rectangular plates, each with a length of l=3l=3l=3 cm and breadth of b=1b=1b=1 cm. The distance between the plates is 3 μm. Out of the following, which are the ways to increase the capacitance by a factor of 10 ? A. l=30l=30l=30 cm, b=1b=1b=1 cm, d=1d=1d=1 μm. B. l=3l=3l=3 cm, b=1b=1b=1 cm, d=30d=30d=30 μm. C. l=6l=6l=6 cm, b=5b=5b=5 cm, d=3d=3d=3 μm. D. l=1l=1l=1 cm, b=1b=1b=1 cm, d=10d=10d=10 μm. E. l=5l=5l=5 cm, b=2b=2b=2 cm, d=1d=1d=1 μm. Choose the correct answer from the options given below :
  1. (A)C and E only
  2. (B)B and D only
  3. (C)A only
  4. (D)C only

Correct answer: (A)

Step-by-step solution →
Q24·PhysicsSingle correctJEE Main 2025
Consider a parallel plate capacitor of area A (of each plate) and separation ‘d’ between the plates. If E is the electric field and ε0\varepsilon_0ε0​ is the permittivity of free space between the plates, then potential energy stored in the capacitor is :-
  1. (A)12ε0E2Ad\dfrac{1}{2}\varepsilon_0 E^2 Ad21​ε0​E2Ad
  2. (B)34ε0E2Ad\dfrac{3}{4}\varepsilon_0 E^2 Ad43​ε0​E2Ad
  3. (C)14ε0E2Ad\dfrac{1}{4}\varepsilon_0 E^2 Ad41​ε0​E2Ad
  4. (D)ε0E2Ad\varepsilon_0 E^2 Adε0​E2Ad

Correct answer: (A)

Step-by-step solution →
Q25·PhysicsSingle correctJEE Main 2025
A parallel-plate capacitor of capacitance 40 μF is connected to a 100 V power supply. Now the intermediate space between the plates is filled with a dielectric material of dielectric constant K = 2. Due to the introduction of the dielectric, the extra charge and the change in the electrostatic energy of the capacitor, respectively, are:
  1. (A)3 mC and 0.2 J
  2. (B)8 mC and 2.0 J
  3. (C)4 mC and 0.2 J
  4. (D)2 mC and 0.2 J

Correct answer: (C)

Step-by-step solution →
Q26·PhysicsSingle correctJEE Advanced 2024
Four identical thin, square metal sheets, S1S_{1}S1​, S2S_{2}S2​, S3S_{3}S3​ and S4S_{4}S4​, each of side aaa are kept parallel to each other with equal distance ddd (≪a\ll a≪a) between them, as shown in the figure. Let C0=ε0a2/dC_{0} = \varepsilon_{0}a^{2}/dC0​=ε0​a2/d, where ε0\varepsilon_{0}ε0​ is the permittivity of free space. Match the quantities mentioned in List-I with their values in List-II and choose the correct option.
List-IList-II
P.The capacitance between S1S_{1}S1​ and S4S_{4}S4​, with S2S_{2}S2​ and S3S_{3}S3​ not connected, is1.3C03C_{0}3C0​
Q.The capacitance between S1S_{1}S1​ and S4S_{4}S4​, with S2S_{2}S2​ shorted to S3S_{3}S3​, is2.C0/2C_{0}/2C0​/2
R.The capacitance between S1S_{1}S1​ and S3S_{3}S3​, with S2S_{2}S2​ shorted to S4S_{4}S4​, is3.C0/3C_{0}/3C0​/3
S.The capacitance between S1S_{1}S1​ and S2S_{2}S2​, with S3S_{3}S3​ shorted to S1S_{1}S1​, and S2S_{2}S2​ shorted to S4S_{4}S4​, is4.2C0/32C_{0}/32C0​/3
5.2C02C_{0}2C0​
  1. (A)P →\to→ 3; Q →\to→ 2; R →\to→ 4; S →\to→ 5
  2. (B)P →\to→ 2; Q →\to→ 3; R →\to→ 2; S →\to→ 1
  3. (C)P →\to→ 3; Q →\to→ 2; R →\to→ 4; S →\to→ 1
  4. (D)P →\to→ 3; Q →\to→ 2; R →\to→ 2; S →\to→ 5

Correct answer: (C)

Step-by-step solution →
Q27·PhysicsSingle correctJEE Main 2024
A capacitor is made of a flat plate of area A and a second plate having a stair-like structure as shown in figure. If the area of each stair is A3\dfrac{A}{3}3A​ and the height is d, the capacitance of the arrangement is:
  1. (A)11ε0A18d\dfrac{11\varepsilon_0 A}{18 d}18d11ε0​A​
  2. (B)13ε0A17d\dfrac{13\varepsilon_0 A}{17 d}17d13ε0​A​
  3. (C)11ε0A20d\dfrac{11\varepsilon_0 A}{20 d}20d11ε0​A​
  4. (D)18ε0A11d\dfrac{18\varepsilon_0 A}{11 d}11d18ε0​A​

Correct answer: (A)

Step-by-step solution →
Q28·PhysicsSingle correctJEE Main 2024
A capacitor has air as dielectric medium and two conducting plates of area 12 cm2^22 and they are 0.6 cm apart. When a slab of dielectric having area 12 cm2^22 and 0.6 cm thickness is inserted between the plates, one of the conducting plates has to be moved by 0.2 cm to keep the capacitance same as in previous case. The dielectric constant of the slab is: (Given ε=8.834×10−12\varepsilon=8.834\times10^{-12}ε=8.834×10−12 F/m)
  1. (A)1.50
  2. (B)1.33
  3. (C)0.66
  4. (D)1

Correct answer: (A)

Step-by-step solution →
Q29·PhysicsNumericalJEE Main 2024
A capacitor of 10 μ10\,\mu10μF capacitance whose plates are separated by 10 mm through air and each plate has area 4 cm2^{2}2 is now filled equally with two dielectric media of K1=2K_{1} = 2K1​=2, K2=3K_{2} = 3K2​=3 respectively as shown in figure. If new force between the plates is 8 N. The supply voltage is ______ V.

Correct answer: 80

Step-by-step solution →
Q30·PhysicsNumericalJEE Main 2024
Three capacitors of capacitances 25 μF25\ \mu\text{F}25 μF, 30 μF30\ \mu\text{F}30 μF and 45 μF45\ \mu\text{F}45 μF are connected in parallel to a supply of 100 V. The energy stored in this combination is E. When these capacitors are connected in series to the same supply, the stored energy is 9xE\dfrac{9}{x}Ex9​E. The value of xxx is ___.

Correct answer: 86

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Q31·PhysicsNumericalJEE Main 2024
The electric field between the two parallel plates of a capacitor of 1.5 μF1.5\ \mu\text{F}1.5 μF capacitance drops to one third of its initial value in 6.6 μs6.6\ \mu\text{s}6.6 μs when the plates are connected by a thin wire. The resistance of this wire is ___ Ω\OmegaΩ. (Given log⁡3=1.1\log 3 = 1.1log3=1.1.)

Correct answer: 4

Step-by-step solution →
Q32·PhysicsNumericalJEE Main 2024
A parallel plate capacitor of capacitance 12.5 pF is charged by a battery connected between its plates to potential difference of 12.0 V. The battery is now disconnected and a dielectric slab (εr=6)(\varepsilon_r=6)(εr​=6) is inserted between the plates. The change in its potential energy after inserting the dielectric slab is ______ ×10−12\times10^{-12}×10−12 J.

Correct answer: 750

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Q33·PhysicsNumericalJEE Main 2024
Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle θ\thetaθ with each other. When suspended in water the angle remains the same. If density of the material of the sphere is 1.5 g/cc1.5\,g/cc1.5g/cc, the dielectric constant of water will be ___. (Take density of water =1 g/cc=1\,g/cc=1g/cc)

Correct answer: 3

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Q34·PhysicsSingle correctJEE Main 2024
Two identical capacitors have same capacitance CCC. One of them is charged to the potential VVV and other to the potential 2V2V2V. The negative ends of both are connected together. When the positive ends are also joined together, the decrease in energy of the combined system is:
  1. (A)14CV2\dfrac14 CV^241​CV2
  2. (B)2CV22CV^22CV2
  3. (C)12CV2\dfrac12 CV^221​CV2
  4. (D)34CV2\dfrac34 CV^243​CV2

Correct answer: (A)

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Q35·PhysicsSingle correctJEE Main 2024
Force between two point charges q1q_1q1​ and q2q_2q2​ placed in vacuum at 'rrr' cm apart is F. Force between them when placed in a medium having dielectric K=5K=5K=5 at 'r/5r/5r/5' cm apart will be:
  1. (A)F25\dfrac{F}{25}25F​
  2. (B)5F
  3. (C)F5\dfrac{F}{5}5F​
  4. (D)25F

Correct answer: (B)

Step-by-step solution →
Q36·PhysicsNumericalJEE Main 2024
A parallel plate capacitor with plate separation 5 mm is charged up by a battery. It is found that on introducing a dielectric sheet of thickness 2 mm, while keeping the battery connections intact, the capacitor draws 25% more charge from the battery than before. The dielectric constant of the sheet is ______.

Correct answer: 2

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Q37·PhysicsNumericalJEE Main 2024
Two identical charged spheres are suspended by string of equal lengths. The string make an angle of 37∘37^\circ37∘ with each other. When suspended in a liquid of density 0.7 g/cm3^33, the angle remains same. If density of material of the sphere is 1.4 g/cm3^33, the dielectric constant of the liquid is ______. (tan⁡37∘=34)\left(\tan 37^\circ=\dfrac{3}{4}\right)(tan37∘=43​)

Correct answer: 2

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Q38·PhysicsNumericalJEE Main 2024
A capacitor of capacitance CCC and potential VVV has energy EEE. It is connected to another capacitor of capacitance 2C2C2C and potential 2V2V2V. Then the loss of energy is x3E\dfrac{x}{3}E3x​E, where xxx is ___

Correct answer: 2

Step-by-step solution →
Q39·PhysicsNumericalJEE Main 2024
In the given figure, the charge stored in 6 μ\muμF capacitor, when points A and B are joined by a connecting wire is ___ μ\muμC.

Correct answer: 36

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Q40·PhysicsSingle correctJEE Advanced 2023
A container has a base of 50 cm ×\times× 5 cm and height 50 cm, as shown in the figure. It has two parallel electrically conducting walls each of area 50 cm ×\times× 50 cm. The remaining walls of the container are thin and non-conducting. The container is being filled with a liquid of dielectric constant 3 at a uniform rate of 250 cm3 s−1cm^3\ s^{-1}cm3 s−1. What is the value of the capacitance of the container after 10 seconds? [Given: Permittivity of free space ε0=9×10−12 C2N−1m−2\varepsilon_0 = 9 \times 10^{-12}\ C^2N^{-1}m^{-2}ε0​=9×10−12 C2N−1m−2 , the effects of the non-conducting walls on the capacitance are negligible
  1. (A)27 pF
  2. (B)63 pF
  3. (C)81 pF
  4. (D)135 pF

Correct answer: (B)

Step-by-step solution →
Q41·PhysicsNumericalJEE Main 2023
In the given figure the total charge stored in the combination of capacitors is 100 μ100\ \mu100 μC. The value of 'x' is __________.

Correct answer: 5

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Q42·PhysicsNumericalJEE Main 2023
In the circuit shown, the energy stored in the capacitor is nnn μ\muμJ. The value of n is ____.

Correct answer: 75

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Q43·PhysicsSingle correctJEE Main 2023
In the network shown below, the charge accumulated in the capacitor in steady state will be:
  1. (A)7.2 μ\muμC
  2. (B)4.8 μ\muμC
  3. (C)10.3 μ\muμC
  4. (D)12 μ\muμC

Correct answer: (A)

Step-by-step solution →
Q44·PhysicsNumericalJEE Main 2023
In the given circuit, C1=2 μC_1=2\ \muC1​=2 μF, C2=0.2 μC_2=0.2\ \muC2​=0.2 μF, C3=2 μC_3=2\ \muC3​=2 μF, C4=4 μC_4=4\ \muC4​=4 μF, C5=2 μC_5=2\ \muC5​=2 μF, C6=2 μC_6=2\ \muC6​=2 μF. The charge stored on capacitor C4C_4C4​ is ____ μ\muμC.

Correct answer: 4

Step-by-step solution →
Q45·PhysicsSingle correctJEE Main 2023
A parallel plate capacitor of capacitance 2 F is charged to a potential V. The energy stored in the capacitor is E1E_1E1​. The capacitor is now connected to another uncharged identical capacitor in parallel combination. The energy stored in the combination is E2E_2E2​. The ratio E2/E1E_2/E_1E2​/E1​ is :
  1. (A)2:12 : 12:1
  2. (B)1:21 : 21:2
  3. (C)1:41 : 41:4
  4. (D)2:32 : 32:3

Correct answer: (B)

Step-by-step solution →
Q46·PhysicsSingle correctJEE Main 2023
A capacitor of capacitance C is charged to a potential V. The flux of the electric field through a closed surface enclosing the positive plate of the capacitor is:
  1. (A)CV2ε0\dfrac{CV}{2\varepsilon_0}2ε0​CV​
  2. (B)2CVε0\dfrac{2CV}{\varepsilon_0}ε0​2CV​
  3. (C)CVε0\dfrac{CV}{\varepsilon_0}ε0​CV​
  4. (D)Zero

Correct answer: (C)

Step-by-step solution →
Q47·PhysicsSingle correctJEE Main 2023
The equivalent capacitance of the combination shown is:
  1. (A)C2\dfrac{C}{2}2C​
  2. (B)4C
  3. (C)3C
  4. (D)53C\dfrac53 C35​C

Correct answer: (C)

Step-by-step solution →
Q48·PhysicsSingle correctJEE Main 2023
The distance between two plates of a capacitor is ddd and its capacitance is C1C_1C1​ when air is the medium between the plates. If a metal sheet of thickness 2d3\tfrac{2d}{3}32d​ and of the same area as the plates is introduced between the plates, the capacitance of the capacitor becomes C2C_2C2​. The ratio C2C1\tfrac{C_2}{C_1}C1​C2​​ is:
  1. (A)2:12:12:1
  2. (B)4:14:14:1
  3. (C)3:13:13:1
  4. (D)1:11:11:1

Correct answer: (C)

Step-by-step solution →
Q49·PhysicsNumericalJEE Main 2023
A 600 pF capacitor is charged by a 200 V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. The electrostatic energy lost in the process is ____ μ\muμJ.

Correct answer: 6

Step-by-step solution →
Q50·PhysicsNumericalJEE Main 2023
A parallel plate capacitor with plate area AAA and plate separation ddd is filled with a dielectric material of dielectric constant K=4K=4K=4. The thickness of the dielectric material is xxx, where x<dx<dx<d. Let C1C_1C1​ and C2C_2C2​ be the capacitance of the system for x=13dx=\dfrac{1}{3}dx=31​d and x=23dx=\dfrac{2}{3}dx=32​d, respectively. If C1=2 μFC_1=2\,\mu FC1​=2μF then the value of C2C_2C2​ is _____ μF\mu FμF.

Correct answer: 3

Step-by-step solution →
Q51·PhysicsNumericalJEE Main 2023
As shown in the figure, two parallel plate capacitors having equal plate area of 200 cm2^22 are joined together. The equivalent capacitance of the combination is x ε0x\,\varepsilon_0xε0​ F. The value of xxx is

Correct answer: 5

Step-by-step solution →
Q52·PhysicsSingle correctJEE Main 2023
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Two metallic spheres are charged to the same potential. One of them is hollow and another is solid, and both have the same radii. Solid sphere will have lower charge than the hollow one. Reason R: Capacitance of metallic spheres depend on the radii of spheres. In the light of the above statements, choose the correct answer from the options given below.
  1. (A)Both A and R are true and R is the correct explanation of A
  2. (B)Both A and R are true but R is not the correct explanation of A
  3. (C)A is true but R is false
  4. (D)A is false but R is true

Correct answer: (C)

Step-by-step solution →
Q53·PhysicsNumericalJEE Main 2023
Two parallel plate capacitors C1C_1C1​ and C2C_2C2​ each having capacitance of 10 μF10\,\mu F10μF are individually charged by a 100100100 V D.C. source. Capacitor C1C_1C1​ is kept connected to the source and a dielectric slab is inserted between it plates. Capacitor C2C_2C2​ is disconnected from the source and then a dielectric slab is inserted in it. Afterwards the capacitor C1C_1C1​ is also disconnected from the source and the two capacitors are finally connected in parallel combination. The common potential of the combination will be _________ V. (Assuming Dielectric constant =10=10=10)

Correct answer: 55

Step-by-step solution →
Q54·PhysicsNumericalJEE Main 2023
A capacitor of capacitance 900 μF900\,\mu F900μF is charged by a 100100100 V battery. The capacitor is disconnected from the battery and connected to another uncharged identical capacitor such that one plate of uncharged capacitor connected to positive plate and another plate of uncharged capacitor connected to negative plate of the charged capacitor. The loss of energy in this process is measured as x×10−2x\times10^{-2}x×10−2 J. The value of xxx is

Correct answer: 225

Step-by-step solution →
Q55·PhysicsNumericalJEE Main 2023
A capacitor has capacitance 5 μF5\,\mu F5μF when its parallel plates are separated by air medium of thickness ddd. A slab of material of dielectric constant 1.5 having area equal to that of plates but thickness d2\frac{d}{2}2d​ is inserted between the plates. Capacitance of the capacitor in the presence of slab will be ______ μF\mu FμF.

Correct answer: 6

Step-by-step solution →
Q56·PhysicsSingle correctJEE Main 2023
A parallel plate capacitor has plate area 40 cm2^22 and plates separation 2 mm. The space between the plates is filled with a dielectric medium of thickness 1 mm and dielectric constant 5. The capacitance of the system is:
  1. (A)24ε024\varepsilon_024ε0​ F
  2. (B)103ε0\dfrac{10}{3}\varepsilon_0310​ε0​ F
  3. (C)310ε0\dfrac{3}{10}\varepsilon_0103​ε0​ F
  4. (D)10ε010\varepsilon_010ε0​ F

Correct answer: (B)

Step-by-step solution →
Q57·PhysicsNumericalJEE Main 2023
A parallel plate capacitor with air between the plate has a capacitance of 151515 pF. The separation between the plate becomes twice and the space between them is filled with a medium of dielectric constant 3.53.53.5. Then the capacitance becomes x4\dfrac{x}{4}4x​ pF. The value of xxx is _________

Correct answer: 105

Step-by-step solution →
Q58·PhysicsNumericalJEE Advanced 2022
In the following circuit C1=12 μFC_1 = 12\ \mu FC1​=12 μF, C2=C3=4 μFC_2 = C_3 = 4\ \mu FC2​=C3​=4 μF and C4=C5=2 μFC_4 = C_5 = 2\ \mu FC4​=C5​=2 μF. The charge stored in C3C_3C3​ is ________ μC\mu CμC.

Correct answer: 8.00

Step-by-step solution →
Q59·PhysicsMultiple correctJEE Advanced 2022
A medium having dielectric constant K>1K > 1K>1 fills the space between the plates of a parallel plate capacitor. The plates have large area, and the distance between them is ddd. The capacitor is connected to a battery of voltage VVV, as shown in Figure (a). Now, both the plates are moved by a distance d/2 of from their original positions, as shown in Figure (b). In the process of going from the configuration depicted in Figure (a) to that in Figure (b), which of the following statement(s) is(are) correct?
  1. (A)The electric field inside the dielectric material is reduced by a factor of 2K.
  2. (B)The capacitance is decreased by a factor of 1K+1\frac{1}{K+1}K+11​ .
  3. (C)The voltage between the capacitor plates is increased by a factor of (K+1).
  4. (D)The work done in the process DOES NOT depend on the presence of the dielectric material.

Correct answer: (B)

Step-by-step solution →
Q60·PhysicsSingle correctJEE Main 2022
Two identical thin metal plates has charge q1q_1q1​ and q2q_2q2​ respectively such that q1>q2q_1 > q_2q1​>q2​. The plates were brought close to each other to form a parallel plate capacitor of capacitance C. The potential difference between them is :
  1. (A)(q1+q2)C\frac{(q_1 + q_2)}{C}C(q1​+q2​)​
  2. (B)(q1−q2)C\frac{(q_1 - q_2)}{C}C(q1​−q2​)​
  3. (C)(q1−q2)2C\frac{(q_1 - q_2)}{2C}2C(q1​−q2​)​
  4. (D)2(q1−q2)C\frac{2(q_1 - q_2)}{C}C2(q1​−q2​)​

Correct answer: (C)

Step-by-step solution →
Q61·PhysicsSingle correctJEE Main 2022
Two capacitors, each having capacitance 40 μF are connected in series. The space between one of the capacitors is filled with dielectric material of dielectric constant K such that the equivalence capacitance of the system became 24 μF. The value of K will be :
  1. (A)1.5
  2. (B)2.5
  3. (C)1.2
  4. (D)3

Correct answer: (A)

Step-by-step solution →
Q62·PhysicsSingle correctJEE Main 2022
A slab of dielectric constant K has the same cross-sectional area as the plates of a parallel plate capacitor and thickness 34d\dfrac{3}{4}d43​d, where d is the separation of the plates. The capacitance of the capacitor when the slab is inserted between the plates will be : (Given CoC_oCo​ = capacitance of capacitor with air as medium between plates.)
  1. (A)4KC03+K\dfrac{4KC_0}{3+K}3+K4KC0​​
  2. (B)3KC03+K\dfrac{3KC_0}{3+K}3+K3KC0​​
  3. (C)3+K4KC0\dfrac{3+K}{4KC_0}4KC0​3+K​
  4. (D)K4+K\dfrac{K}{4+K}4+KK​

Correct answer: (A)

Step-by-step solution →
Q63·PhysicsNumericalJEE Main 2022
A parallel plate capacitor with width 4 cm, length 8 cm and separation between the plates of 4mm is connected to a battery of 20 V. A dielectric slab of dielectric constant 5 having length 1cm, width 4 cm and thickness 4 mm is inserted between the plates of parallel plate capacitor. The electrostatic energy of this system will be………∈0_00​ J. (Where ∈0_00​ is the permittivity of free space)

Correct answer: 240

Step-by-step solution →
Q64·PhysicsSingle correctJEE Main 2022
The total charge on the system of capacitance C1_{1}1​ = 1μF, C2_{2}2​ = 2μF, C3_{3}3​ = 4μF and C4_{4}4​ = 3μF connected in parallel is (Assume a battery of 20V is connected to the combination)
  1. (A)200μC
  2. (B)200C
  3. (C)10μC
  4. (D)10C

Correct answer: (A)

Step-by-step solution →
Q65·PhysicsNumericalJEE Main 2022
A composite parallel plate capacitor is made up of two different dielectric materials with different thickness (t1_{1}1​ and t2_{2}2​) as shown in figure. The two different dielectric material are separated by a conducting foil F. The voltage of the conducting foil is _____V.

Correct answer: 60

Step-by-step solution →
Q66·PhysicsSingle correctJEE Main 2022
A source of potential difference V is connected to the combination of two identical capacitors as shown in the figure. When key 'K' is closed, the total energy stored across the combination is E1E_1E1​. Now key 'K' is opened and dielectric of dielectric constant 5 is introduced between the plates of the capacitors. The total energy stored across the combination is now E2E_2E2​. The ratio E1/E2E_1/E_2E1​/E2​ will be :
  1. (A)110\frac{1}{10}101​
  2. (B)25\frac{2}{5}52​
  3. (C)513\frac{5}{13}135​
  4. (D)526\frac{5}{26}265​

Correct answer: (C)

Step-by-step solution →
Q67·PhysicsSingle correctJEE Main 2022
A condenser of 2 μ\muμF capacitance is charged steadily from 0 to 5C. Which of the following graph represents correctly the variation of potential difference (V) across it's plates with respect to the charge (Q) on the condenser ?
  1. (A)(A)
  2. (B)(B)
  3. (C)(C)
  4. (D)(D)

Correct answer: (A)

Step-by-step solution →
Q68·PhysicsSingle correctJEE Main 2022
A parallel plate capacitor filled with a medium of dielectric constant 10, is connected across a battery and is charged. The dielectric slab is replaced by another slab of dielectric constant 15. Then the energy of capacitor will :
  1. (A)increase by 50%
  2. (B)decrease by 15%
  3. (C)increase by 25%
  4. (D)increase by 33%

Correct answer: (A)

Step-by-step solution →
Q69·PhysicsSingle correctJEE Main 2022
A capacitor is discharging through a resistor R. Consider in time t1t_1t1​, the energy stored in the capacitor reduces to half of its initial value and in time t2t_2t2​, the charge stored reduces to one eighth of its initial value. The ratio t1/t2t_1/t_2t1​/t2​ will be :
  1. (A)1/2
  2. (B)1/3
  3. (C)1/4
  4. (D)1/6

Correct answer: (D)

Step-by-step solution →
Q70·PhysicsNumericalJEE Main 2022
A capacitor C1_11​ of capacitance 5μF is charged to a potential of 30 V using a battery. The battery is then removed and the charged capacitor is connected to an uncharged capacitor C2_22​ of capacitance 10μF as shown in figure. When the switch is closed charge flows between the capacitors. At equilibrium, the charge on the capacitor C2_22​ is ________ μC .

Correct answer: 100

Step-by-step solution →
Q71·PhysicsSingle correctJEE Main 2022
A force of 10N acts on a charged particle placed between two plates of a charged capacitor. If one plate of capacitor is removed, then the force acting on that particle will be :
  1. (A)5 N
  2. (B)10 N
  3. (C)20 N
  4. (D)Zero

Correct answer: (A)

Step-by-step solution →
Q72·PhysicsNumericalJEE Main 2022
A capacitor of capacitance 50 pF is charged by 100 V source. It is then connected to another uncharged identical capacitor. Electrostatic energy loss in the process is ____ nJ.

Correct answer: 125

Step-by-step solution →
Q73·PhysicsNumericalJEE Main 2022
A paralle plate capacitor is made up of stair like structure with a palte area A of each stair and that is connected with a wire of length b, as shown in the figure. The capacitance of the arrangement is x15ε0Ab\dfrac{x}{15}\dfrac{\varepsilon_0 A}{b}15x​bε0​A​ . The value of x is ________ .

Correct answer: 23

Step-by-step solution →
Q74·PhysicsSingle correctJEE Main 2022
Assertion (A) : Non-polar amterials do not have my permanent dipole moment. Reason (R) : When an non-polar material is placed in a electric field. the centre of the positive charge distribution of it's individual atom or molecule coinsides with the centre of the negative charge distribution. In the light of above statements, choose the most appropriate answer from the options given below.
  1. (A)Both (A) and (R) are correct and (R) is the correct explanation of (A).
  2. (B)Both (A) and (R) are correct and (R) is not the correct explanation of (A).
  3. (C)(A) is correct but (R) is not correct.
  4. (D)(A) is not correct but (R) is correct.

Correct answer: (C)

Step-by-step solution →
Q75·PhysicsSingle correctJEE Main 2022
A parallel plate capacitor with plate area A and plate separation d=2 m has a capacitance of 4 μF. The new capacitance of the system if half of the space between them is filled with a dielectric material of dielectric constant K=3 (as shown in figure) will be :
  1. (A)2μF
  2. (B)32μF
  3. (C)6μF
  4. (D)8μF

Correct answer: (C)

Step-by-step solution →
Q76·PhysicsSingle correctJEE Main 2022
The charge on capacitor of capacitance 15μF in the figure given below is :
  1. (A)60μc
  2. (B)130μc
  3. (C)260 μc
  4. (D)585 μc

Correct answer: (A)

Step-by-step solution →
Q77·PhysicsSingle correctJEE Main 2022
Two capacitors having capacitance C1C_{1}C1​ and C2C_{2}C2​ respectively are connected as shown in figure. Initially, capacitor C1C_{1}C1​ is charged to a potential difference V volt by a battery. The battery is then removed and the charged capacitor C1C_{1}C1​ is now connected to uncharged capacitor C2C_{2}C2​ by closing the switch S. The amount of charge on the capacitor C2C_{2}C2​, after equilibrium is :
  1. (A)C1C2(C1+C2)V\frac{C_{1}C_{2}}{\left(C_{1}+C_{2}\right)}V(C1​+C2​)C1​C2​​V
  2. (B)(C1+C2)C1C2V\frac{\left(C_{1}+C_{2}\right)}{C_{1}C_{2}}VC1​C2​(C1​+C2​)​V
  3. (C)(C1+C2)V(C_{1}+C_{2})V(C1​+C2​)V
  4. (D)(C1−C2)V(C_{1}-C_{2})V(C1​−C2​)V

Correct answer: (A)

Step-by-step solution →
Q78·PhysicsSingle correctJEE Main 2022
Two metallic plates form a parallel plate capacitor. The distance between the plates is 'd'. A metal sheet of thickness d2\frac{d}{2}2d​ and of area equal to area of each plate is introduced between the plates. What will be the ratio of the new capacitance to the original capacitance of the capacitor ?
  1. (A)2:1
  2. (B)1:2
  3. (C)1:4
  4. (D)4:1

Correct answer: (A)

Step-by-step solution →
Q79·PhysicsNumericalJEE Main 2022
The equivalent capacitance between points A and B in below shown figure will be _____ μF.

Correct answer: 6

Step-by-step solution →
Q80·PhysicsSingle correctJEE Main 2022
A parallel plate capacitor is formed by two plates each of area 30π30\pi30π cm2^{2}2 separated by 1 mm. A material of dielectric strength 3.6×1073.6\times10^{7}3.6×107 Vm−1^{-1}−1 is filled between the plates. If the maximum charge that can be stored on the capacitor without causing any dielectric breakdown is 7×10−67\times10^{-6}7×10−6 C, the value of dielectric constant of the material is : {Use:14πε0=9×109 Nm2C−2}\left\{\text{Use}:\dfrac{1}{4\pi\varepsilon_{0}}=9\times10^{9}\ \text{Nm}^{2}\text{C}^{-2}\right\}{Use:4πε0​1​=9×109 Nm2C−2}
  1. (A)1.66
  2. (B)1.75
  3. (C)2.25
  4. (D)2.33

Correct answer: (D)

Step-by-step solution →
Q81·PhysicsSingle correctJEE Main 2022
If the charge on a capacitor is increased by 2 C, the energy stored in it increases by 44%. The original charge on the capacitor is (in C) :
  1. (A)10
  2. (B)20
  3. (C)30
  4. (D)40

Correct answer: (A)

Step-by-step solution →
Q82·PhysicsSingle correctJEE Main 2021
A capacitor is connected to a 20 V battery through a resistance of 10Ω. It is found that the potential difference across the capacitor rises to 2 V in 1 μs. The capacitance of the capacitor is ....................μF. Given : ln⁡(109)=0.105\ln\left(\frac{10}{9}\right) = 0.105ln(910​)=0.105
  1. (A)9.52
  2. (B)0.95
  3. (C)0.105
  4. (D)1.85

Correct answer: (B)

Step-by-step solution →
Q83·PhysicsNumericalJEE Main 2021
A capacitor of 50 μ\muμF is connected in a circuit as shown in figure. The charge on the upper plate of the capacitor is ______ μ\muμC.

Correct answer: 100

Step-by-step solution →
Q84·PhysicsNumericalJEE Main 2021
A parallel plate capacitor of capacitance 200 μ\muμF is connected to a battery of 200 V. A dielectric slab of dielectric constant 2 is now inserted into the space between plates of capacitor while the battery remain connected. The change in the electrostatic energy in the capacitor will be______J.

Correct answer: 4

Step-by-step solution →
Q85·PhysicsSingle correctJEE Main 2021
Three capacitors C1C_{1}C1​ = 2μF, C2C_{2}C2​ = 6 μF and C3C_{3}C3​ = 12 μF are connected as shown in figure. Find the ratio of the charges on capacitors C1C_{1}C1​, C2C_{2}C2​ and C3C_{3}C3​ respectively :
  1. (A)2 : 1 : 1
  2. (B)2 : 3 : 3
  3. (C)1 : 2 : 2
  4. (D)3 : 4 : 4

Correct answer: (C)

Step-by-step solution →
Q86·PhysicsSingle correctJEE Main 2021
The material filled between the plates of a parallel plate capacitor has resistivity 200 Ω\OmegaΩm. The value of capacitance of the capacitor is 2 pF. If a potential difference of 40 V is applied across the plates of the capacitor, then the value of leakage current flowing out of the capacitor is : (given the value of relative permitivity of material is 50)
  1. (A)9.0 μ\muμA
  2. (B)9.0 mA
  3. (C)0.9 mA
  4. (D)0.9 μ\muμA

Correct answer: (C)

Step-by-step solution →
Q87·PhysicsSingle correctJEE Main 2021
A parallel - plate capacitor with plate area A has separation d between the plates. Two dielectric slabs of dielectric constant K1K_{1}K1​ and K2K_{2}K2​ of same area A/2 and thickness d/2 are inserted in the space between the plates. The capacitance of the capacitor will be given by :
  1. (A)ε0Ad(12+K1K2K1+K2)\frac{\varepsilon_{0}A}{d}\left(\frac{1}{2} + \frac{K_{1}K_{2}}{K_{1} + K_{2}}\right)dε0​A​(21​+K1​+K2​K1​K2​​)
  2. (B)ε0Ad(12+K1K22(K1+K2))\frac{\varepsilon_{0}A}{d}\left(\frac{1}{2} + \frac{K_{1}K_{2}}{2\left(K_{1} + K_{2}\right)}\right)dε0​A​(21​+2(K1​+K2​)K1​K2​​)
  3. (C)ε0Ad(12+K1+K2K1K2)\frac{\varepsilon_{0}A}{d}\left(\frac{1}{2} + \frac{K_{1} + K_{2}}{K_{1}K_{2}}\right)dε0​A​(21​+K1​K2​K1​+K2​​)
  4. (D)ε0Ad(12+2(K1+K2)K1K2)\frac{\varepsilon_{0}A}{d}\left(\frac{1}{2} + \frac{2\left(K_{1} + K_{2}\right)}{K_{1}K_{2}}\right)dε0​A​(21​+K1​K2​2(K1​+K2​)​)

Correct answer: (A)

Step-by-step solution →
Q88·PhysicsSingle correctJEE Main 2021
Two capacitors of capacities 2C and C are joined in parallel and charge up to potential V. The battery is removed and the capacitor of capacity C is filled completely with a medium of dielectric constant K. The potential difference across the capacitors will now be :
  1. (A)3VK\frac{3V}{K}K3V​
  2. (B)VK\frac{V}{K}KV​
  3. (C)VK+2\frac{V}{K + 2}K+2V​
  4. (D)3VK+2\frac{3V}{K + 2}K+23V​

Correct answer: (D)

Step-by-step solution →
Q89·PhysicsSingle correctJEE Main 2021
A capacitor of capacitance C = 1μF is suddenly connected to a battery of 100 volt through a resistance R = 100Ω. The time taken for the capacitor to be charged to get 50 V is : [Take ln 2 = 0.69 ]
  1. (A)3.33×10−43.33 \times 10^{-4}3.33×10−4 s
  2. (B)1.44×10−41.44 \times 10^{-4}1.44×10−4 s
  3. (C)0.30×10−40.30 \times 10^{-4}0.30×10−4 s
  4. (D)0.69×10−40.69 \times 10^{-4}0.69×10−4 s

Correct answer: (D)

Step-by-step solution →
Q90·PhysicsSingle correctJEE Main 2021
A simple pendulum of mass 'm', length 'ℓ\ellℓ' and charge '+q' suspended in the electric field produced by two conducting parallel plates as shown. The value of deflection of pendulum in equilibrium position will be :
  1. (A)tan⁡−1[qmg×C2(V2−V1)(C1+C2)(d−t)]\tan^{-1}\left[\frac{q}{mg} \times \frac{C_2(V_2 - V_1)}{(C_1 + C_2)(d - t)}\right]tan−1[mgq​×(C1​+C2​)(d−t)C2​(V2​−V1​)​]
  2. (B)tan⁡−1[qmg×C1(V1+V2)(C1+C2)(d−1)]\tan^{-1}\left[\frac{q}{mg} \times \frac{C_1(V_1 + V_2)}{(C_1 + C_2)(d - 1)}\right]tan−1[mgq​×(C1​+C2​)(d−1)C1​(V1​+V2​)​]
  3. (C)tan⁡−1[qmg×C1(V2−V1)(C1+C2)(d−t)]\tan^{-1}\left[\frac{q}{mg} \times \frac{C_1(V_2 - V_1)}{(C_1 + C_2)(d - t)}\right]tan−1[mgq​×(C1​+C2​)(d−t)C1​(V2​−V1​)​]
  4. (D)tan⁡−1[qmg×C2(V1+V2)(C1+C2)(d−t)]\tan^{-1}\left[\frac{q}{mg} \times \frac{C_2(V_1 + V_2)}{(C_1 + C_2)(d - t)}\right]tan−1[mgq​×(C1​+C2​)(d−t)C2​(V1​+V2​)​]

Correct answer: (D)

Step-by-step solution →
Q91·PhysicsSingle correctJEE Main 2021
In the reported figure, a capacitor is formed by placing a compound dielectric between the plates of parallel plate capacitor. The expression for the capacity of the said capacitor will be : (Given area of plate = A)
  1. (A)1534 Kε0Ad\frac{15}{34} \ \frac{K \varepsilon_0 A}{d}3415​ dKε0​A​
  2. (B)156 Kε0Ad\frac{15}{6} \ \frac{K \varepsilon_0 A}{d}615​ dKε0​A​
  3. (C)256 Kε0Ad\frac{25}{6} \ \frac{K \varepsilon_0 A}{d}625​ dKε0​A​
  4. (D)96 Kε0Ad\frac{9}{6} \ \frac{K \varepsilon_0 A}{d}69​ dKε0​A​

Correct answer: (A)

Step-by-step solution →
Q92·PhysicsSingle correctJEE Main 2021
A parallel plate capacitor with plate area 'A' and distance of separation 'd' is filled with a dielectric. What is the capacity of the capacitor when permittivity of the dielectric varies as: ε(x)=ε0+kx\varepsilon\left(x\right) = \varepsilon_0 + kxε(x)=ε0​+kx, for (0<x≤d2)\left(0 < x \leq \frac{d}{2}\right)(0<x≤2d​) ε(x)=ε0+k(d−x)\varepsilon\left(x\right) = \varepsilon_0 + k\left(d - x\right)ε(x)=ε0​+k(d−x), for (d2≤x≤d)\left(\frac{d}{2} \leq x \leq d\right)(2d​≤x≤d)
  1. (A)0
  2. (B)kA2 ℓn(2ε02ε0−kd)\frac{kA}{2}\ \ell n\left(\frac{2\varepsilon_0}{2\varepsilon_0 - kd}\right)2kA​ ℓn(2ε0​−kd2ε0​​)
  3. (C)kA2 ℓn(2ε0+kd2ε0)\frac{kA}{2\ \ell n\left(\frac{2\varepsilon_0 + kd}{2\varepsilon_0}\right)}2 ℓn(2ε0​2ε0​+kd​)kA​
  4. (D)(ε0+kd2)2/kA\left(\varepsilon_0 + \frac{kd}{2}\right)^{2/kA}(ε0​+2kd​)2/kA

Correct answer: (C)

Step-by-step solution →
Q93·PhysicsSingle correctJEE Main 2021
If qfq_fqf​ is the free charge on the capacitor plates and qbq_bqb​ is the bound charge on the dielectric slab of dielectric constant k placed between the capacitor plates, then bound charge qbq_bqb​ can be expressed as :
  1. (A)qb=qf(1+1k)q_b = q_f\left(1 + \frac{1}{\sqrt{k}}\right)qb​=qf​(1+k​1​)
  2. (B)qb=qf(1−1k)q_b = q_f\left(1 - \frac{1}{\sqrt{k}}\right)qb​=qf​(1−k​1​)
  3. (C)qb=qf(1−1k)q_b = q_f\left(1 - \frac{1}{k}\right)qb​=qf​(1−k1​)
  4. (D)qb=qf(1+1k)q_b = q_f\left(1 + \frac{1}{k}\right)qb​=qf​(1+k1​)

Correct answer: (C)

Step-by-step solution →
Q94·PhysicsNumericalJEE Main 2021
The circuit shown in the figure consists of a charged capacitor of capacity 3 µF and a charge of 30 µC. At time t = 0, when the key is closed, the value of current flowing through the 5 MΩ resistor is 'x' µ-A. The value of 'x to the nearest integer is _______.

Correct answer: 2

Step-by-step solution →
Q95·PhysicsNumericalJEE Main 2021
A parallel plate capacitor has plate area 100 m2^{2}2 and plate separation of 10 m. The space between the plates is filled up to a thickness 5 m with a material of dielectric constant of 10. The resultant capacitance of the system is 'x' pF. The value of ε0_{0}0​ = 8.85 × 10−12^{-12}−12 F.m−1^{-1}−1. The value of 'x' to the nearest integer is_____.

Correct answer: 161

Step-by-step solution →
Q96·PhysicsNumericalJEE Main 2021
A 2 μF capacitor C1_{1}1​ is first charged to a potential difference of 10 V using a battery.Then the battery is removed and the capacitor is connected to an uncharged capacitor C2_{2}2​ of 8μF. The charge in C2_{2}2​ on equilibrium condition is_______μC. (Round off to the Nearest Integer)

Correct answer: 16

Step-by-step solution →
Q97·PhysicsNumericalJEE Main 2021
Four identical rectangular plates with length, lll = 2 cm and breadth, b = 32\frac{3}{2}23​ cm are arranged as shown in figure. The equivalent capacitance between A and C is x ε0d\frac{\mathrm{x}\,\varepsilon_0}{\mathrm{d}}dxε0​​. The value of x is ___. (Round off to the Nearest Integer)

Correct answer: 2

Step-by-step solution →
Q98·PhysicsNumericalJEE Main 2021
A parallel plate capacitor whose capacitance C is 14 pF is charged by a battery to a potential difference V = 12V between its plates. The charging battery is now disconnected and a porcelin plate with k = 7 is inserted between the plates, then the plate would oscillate back and forth between the plates with a constant mechanical energy of ______ pJ. (Assume no friction)

Correct answer: 864

Step-by-step solution →
Q99·PhysicsSingle correctJEE Main 2021
For changing the capacitance of a given parallel plate capacitor, a dielectric material of dielectric constant K is used, which has the same area as the plates of the capacitor. The thickness of the dielectric slab is 34\frac{3}{4}43​d, where 'd' is the separation between the plates of parallel plate capacitor. The new capacitance (C') in terms of original capacitance (C0_00​) is given by the following relation :
  1. (A)C′=3+K4KC0C' = \frac{3+K}{4K}C_0C′=4K3+K​C0​
  2. (B)C′=4+K3C0C' = \frac{4+K}{3}C_0C′=34+K​C0​
  3. (C)C′=4KK+3C0C' = \frac{4K}{K+3}C_0C′=K+34K​C0​
  4. (D)C′=43+KC0C' = \frac{4}{3+K}C_0C′=3+K4​C0​

Correct answer: (C)

Step-by-step solution →
Q100·PhysicsNumericalJEE Main 2021
In a parallel plate capacitor set up, the plate area of capacitor is 2 m2^{2}2 and the plates are separated by 1m. If the space between the plates are filled with a dielectric material of thickness 0.5 m and area 2m2^{2}2 (see fig.) the capacitance of the set-up will be _______ ε0_{0}0​. (Dielectric constant of the material = 3.2) (Round off to the Nearest Integer)

Correct answer: 3

Step-by-step solution →
Q101·PhysicsSingle correctJEE Main 2021
Two equal capacitors are first connected in series and then in parallel. The ratio of the equivalent capacities capacities in the two cases will be -
  1. (A)2 : 1
  2. (B)1 : 4
  3. (C)4 : 1
  4. (D)1 : 2

Correct answer: (B)

Step-by-step solution →
Q102·PhysicsSingle correctJEE Main 2020
A parallel plate capacitor has plate of length '\ell', width 'w' and separation of plates is 'd'. It is connected to a battery of emf V. A dielectric slap of the same thickness 'd' and of dielectric constant k = 4 is being, inserted between the plates of the capacitor. At what length of the slab inside plates, will be energy stored in the capacitor be two times the initial energy stored?
  1. (A)2ℓ/32\ell/32ℓ/3
  2. (B)ℓ/2\ell/2ℓ/2
  3. (C)ℓ/4\ell/4ℓ/4
  4. (D)ℓ/3\ell/3ℓ/3

Correct answer: (D)

Step-by-step solution →
Q103·PhysicsSingle correctJEE Main 2020
Two capacitors of capacitances C and 2C are charged to potential differences V and 2V, respectively. These are then connected in parallel in such a manner that the positive terminal of one is connected to the negative terminal of the other. The final energy of this configuration is:
  1. (A)32CV2\dfrac{3}{2}CV^223​CV2
  2. (B)92CV2\dfrac{9}{2}CV^229​CV2
  3. (C)256CV2\dfrac{25}{6}CV^2625​CV2
  4. (D)zero

Correct answer: (A)

Step-by-step solution →
Q104·PhysicsSingle correctJEE Main 2020
In the circuit shown, charge on the 5 μ\muμF capacitor is:
  1. (A)16.36 μ\muμC
  2. (B)5.45 μ\muμC
  3. (C)10.90 μ\muμC
  4. (D)18.00 μ\muμC

Correct answer: (A)

Step-by-step solution →
Q105·PhysicsSingle correctJEE Main 2020
A capacitor C is fully charged with voltage V0V_0V0​. After disconnecting the voltage source, it is connected in parallel with another uncharged capacitor of capacitance. C2\frac{C}{2}2C​. The energy loss in the process after the charge is distributed between the two capacitor is:
  1. (A)16CV02\frac{1}{6}CV_0^{2}61​CV02​
  2. (B)12CV02\frac{1}{2}CV_0^{2}21​CV02​
  3. (C)14CV02\frac{1}{4}CV_0^{2}41​CV02​
  4. (D)13CV02\frac{1}{3}CV_0^{2}31​CV02​

Correct answer: (A)

Step-by-step solution →
Q106·PhysicsSingle correctJEE Main 2020
In the circuit shown in the figure, the total charge is 750 μC and the voltage across capacitor C2_{2}2​ is 20 V. Then the charge on capacitor C2_{2}2​ is
  1. (A)160 μC
  2. (B)650 μC
  3. (C)590 μC
  4. (D)450 μC

Correct answer: (C)

Step-by-step solution →
Q107·PhysicsSingle correctJEE Main 2020
A capacitor is made of two square plats each of side 'a' making a very small angle a between them, as shown in figure. The capacitance will be close to:
  1. (A)ϵ0a2d(1+αad)\dfrac{\epsilon_{0} a^{2}}{d}\left(1+\dfrac{\alpha a}{d}\right)dϵ0​a2​(1+dαa​)
  2. (B)ϵ0a2d(1−αa4d)\dfrac{\epsilon_{0} a^{2}}{d}\left(1-\dfrac{\alpha a}{4d}\right)dϵ0​a2​(1−4dαa​)
  3. (C)ϵ0a2d(1−3αa2d)\dfrac{\epsilon_{0} a^{2}}{d}\left(1-\dfrac{3\alpha a}{2d}\right)dϵ0​a2​(1−2d3αa​)
  4. (D)ϵ0a2d(1−αa2d)\dfrac{\epsilon_{0} a^{2}}{d}\left(1-\dfrac{\alpha a}{2d}\right)dϵ0​a2​(1−2dαa​)

Correct answer: (D)

Step-by-step solution →
Q108·PhysicsSingle correctJEE Main 2020
Effective capacitance of parallel combination of two capacitors C1C_{1}C1​ and C2C_{2}C2​ is 10 μ\muμF. When these capacitor are individually connected to a voltage source of 1 V, the energy stored in the capacitor C2C_{2}C2​ is 4 times that of C1C_{1}C1​. If these capacitors are connected in series, their effective capacitance will be
  1. (A)3.2 μ\muμF
  2. (B)8.4 μ\muμF
  3. (C)1.6 μ\muμF
  4. (D)4.2 μ\muμF

Correct answer: (C)

Step-by-step solution →
Q109·PhysicsSingle correctJEE Main 2020
A parallel plate capacitor has plates of area A separated by distance 'd' between them. It is filled with a dielectric which has a dielectric constant that varies as k(n) = k(1 + \alpha n) where 'x' is he distance measured from one of the plates. If (α\alphaαd) << 1, the total capacitance of the system is best given by the expression:
  1. (A)AKε0d(1+αd2)\dfrac{AK\varepsilon_0}{d}\left(1+\dfrac{\alpha d}{2}\right)dAKε0​​(1+2αd​)
  2. (B)Aε0Kd(1+α2d22)\dfrac{A\varepsilon_0 K}{d}\left(1+\dfrac{\alpha^2 d^2}{2}\right)dAε0​K​(1+2α2d2​)
  3. (C)AKε0d(1+αd)\dfrac{AK\varepsilon_0}{d}(1+\alpha d)dAKε0​​(1+αd)
  4. (D)Aε0Kd[1+(αd2)2]\dfrac{A\varepsilon_0 K}{d}\left[1+\left(\dfrac{\alpha d}{2}\right)^2\right]dAε0​K​[1+(2αd​)2]

Correct answer: (A)

Step-by-step solution →
Q110·PhysicsNumericalJEE Main 2020
A 60 pF capacitor is fully charged by a 20 V supply. It is then disconnected from the supply and is connected to another uncharged 60 pF capacitor in parallel. The electrostatic energy that is lost in this process by the time the charge is redistributed between them is (in nJ) __________.

Correct answer: 6

Step-by-step solution →
Q111·PhysicsMultiple correctJEE Advanced 2019
In the circuit shown, initially there is no charge on capacitors and keys S1S_1S1​ and S2S_2S2​ are open. The values of the capacitors are C1C_1C1​ = 10 μF, C2C_2C2​ = 30 μF and C3C_3C3​ = C4C_4C4​ = 80 μF. Which of the statement(s) is/are correct?
  1. (A)The key S1S_1S1​ is kept closed for long time such that capacitors are fully charged. Now key S2S_2S2​ is closed, at this time, the instantaneous current across 30Ω resistor (between points P and Q) will be 0.2 A (round off to 1st1^{st}1st decimal place).
  2. (B)If key S1S_1S1​ is kept closed for long time such that capacitors are fully charged, the voltage across the capacitor C1C_1C1​ will be 4V.
  3. (C)At time t = 0, the key S1S_1S1​ is closed, the instantaneous current in the closed circuit will be 25 mA
  4. (D)If key S1S_1S1​ is kept closed for long time such that capacitors are fully charged, the voltage difference between points P and Q will be 10 V.

Correct answer: (B), (C)

Step-by-step solution →
Q112·PhysicsNumericalJEE Advanced 2019
A parallel plate capacitor of capacitance C has spacing d between two plates having area A. The region between the plates is filled with N dielectric layers, parallel to its plates, each with thickness δ=dN\delta = \frac{d}{N}δ=Nd​. The dielectric constant of the mthm^{th}mth layer is Km=K(1+mN)K_m = K\left(1+\frac{m}{N}\right)Km​=K(1+Nm​). For a very large N(>103)N\left(>10^3\right)N(>103), the capacitance C is α(Kε0Adln⁡2)\alpha\left(\frac{K\varepsilon_0 A}{d \ln 2}\right)α(dln2Kε0​A​). The value of α will be ______. [ε0\varepsilon_0ε0​ is the permittivity of free space]

Correct answer: 1.00

Step-by-step solution →
Q113·PhysicsSingle correctJEE Main 2019
Two identical parallel plate capacitors, of capacitance C each, have plates of area A, separated by a distance d. The space between the plates of the two capacitors, is filled with three dielectrics, of equal thickness and dielectric constants K1K_1K1​, K2K_2K2​ and K3K_3K3​. The first capacitor is filled as shown in fig. I, and the second one is filled as shown in fig. II. If these two modified capacitors are charged by the same potential V, the ratio of the energy stored in the two, would be (E1E_1E1​ refers to capacitor (I) and E2E_2E2​ to capacitor (II)) :
  1. (A)E1E2=K1K2K3(K1+K2+K3)(K2K3+K3K1+K1K2)\dfrac{E_1}{E_2}=\dfrac{K_1K_2K_3}{(K_1+K_2+K_3)(K_2K_3+K_3K_1+K_1K_2)}E2​E1​​=(K1​+K2​+K3​)(K2​K3​+K3​K1​+K1​K2​)K1​K2​K3​​
  2. (B)E1E2=9K1K2K3(K1+K2+K3)(K2K3+K3K1+K1K2)\dfrac{E_1}{E_2}=\dfrac{9K_1K_2K_3}{(K_1+K_2+K_3)(K_2K_3+K_3K_1+K_1K_2)}E2​E1​​=(K1​+K2​+K3​)(K2​K3​+K3​K1​+K1​K2​)9K1​K2​K3​​
  3. (C)E1E2=(K1+K2+K3)(K2K3+K3K1+K1K2)9K1K2K3\dfrac{E_1}{E_2}=\dfrac{(K_1+K_2+K_3)(K_2K_3+K_3K_1+K_1K_2)}{9K_1K_2K_3}E2​E1​​=9K1​K2​K3​(K1​+K2​+K3​)(K2​K3​+K3​K1​+K1​K2​)​
  4. (D)E1E2=(K1+K2+K3)(K2K3+K3K1+K1K2)K1K2K3\dfrac{E_1}{E_2}=\dfrac{(K_1+K_2+K_3)(K_2K_3+K_3K_1+K_1K_2)}{K_1K_2K_3}E2​E1​​=K1​K2​K3​(K1​+K2​+K3​)(K2​K3​+K3​K1​+K1​K2​)​

Correct answer: (B)

Step-by-step solution →
Q114·PhysicsSingle correctJEE Main 2019
In the given circuit, the charge on 4 μF capacitor will be :
  1. (A)13.4 μC
  2. (B)24 μC
  3. (C)9.6 μC
  4. (D)5.4 μC

Correct answer: (B)

Step-by-step solution →
Q115·PhysicsSingle correctJEE Main 2019
Figure shows charge (q) versus voltage (V) graph for series and parallel combination of to given capacitors. The capacitances are:
  1. (A)40 µF and 10 µF
  2. (B)50 µF and 30 µF
  3. (C)60 µF and 40 µF
  4. (D)20 µF and 30 µF

Correct answer: (A)

Step-by-step solution →
Q116·PhysicsSingle correctJEE Main 2019
The parallel combination of two air filled parallel plate capacitors of capacitance C and nC is connected to a battery of voltage, V. When the capacitor are fully charged, the battery is removed and after that a dielectric material of dielectric constant K is placed between the two plates of the first capacitor. The new potential difference of the combined system is:
  1. (A)VK+n\dfrac{V}{K + n}K+nV​
  2. (B)V
  3. (C)(n+1)V(K+n)\dfrac{(n + 1)V}{(K + n)}(K+n)(n+1)V​
  4. (D)nVK+n\dfrac{nV}{K + n}K+nnV​

Correct answer: (C)

Step-by-step solution →
Q117·PhysicsSingle correctJEE Main 2019
A capacitor with capacitance 5 μF is charged to 5 μC. If the plates are pulled apart to reduce the capacitance to 2 μF, how much work is done?
  1. (A)3.75×10−63.75\times10^{-6}3.75×10−6 J
  2. (B)2.55×10−62.55\times10^{-6}2.55×10−6 J
  3. (C)6.25×10−66.25\times10^{-6}6.25×10−6 J
  4. (D)2.16×10−62.16\times10^{-6}2.16×10−6 J

Correct answer: (A)

Step-by-step solution →
Q118·PhysicsSingle correctJEE Main 2019
Voltage rating of a parallel plate capacitor is 500V. Its dielectric can withstand a maximum electric field of 106 Vm10^{6}\,\dfrac{V}{m}106mV​. The plate area is 10−410^{-4}10−4 m2^{2}2. What is the dielectric constant if the capacitance is 15 pF? (given ϵ0=8.86×10−12\epsilon_{0} = 8.86 \times 10^{-12}ϵ0​=8.86×10−12 C2^{2}2/N m2^{2}2)
  1. (A)3.8
  2. (B)6.2
  3. (C)4.5
  4. (D)8.5

Correct answer: (D)

Step-by-step solution →
Q119·PhysicsSingle correctJEE Main 2019
A parallel plate capacitor has 1μ\muμF capacitance. One of its two plates is given +2μ\muμC charge and the other plate, +4μ\muμC charge. The potential difference developed across the capacitor is:
  1. (A)3V
  2. (B)1V
  3. (C)5V
  4. (D)2V

Correct answer: (B)

Step-by-step solution →
Q120·PhysicsSingle correctJEE Main 2019
In the circuit shown, find C if the effective capacitance of the whole circuit is to be 0.5 μF. All values in the circuit are in μF.
  1. (A)711\frac{7}{11}117​ μF
  2. (B)65\frac{6}{5}56​ μF
  3. (C)4 μF
  4. (D)710\frac{7}{10}107​ μF

Correct answer: (A)

Step-by-step solution →
Q121·PhysicsSingle correctJEE Main 2019
In the figure shown, after the switch 'S' is turned from position 'A' to position 'B', the energy dissipated in the circuit in terms of capacitance 'C' and total charge 'Q' is:
  1. (A)18Q2C\dfrac{1}{8}\dfrac{Q^2}{C}81​CQ2​
  2. (B)38Q2C\dfrac{3}{8}\dfrac{Q^2}{C}83​CQ2​
  3. (C)58Q2C\dfrac{5}{8}\dfrac{Q^2}{C}85​CQ2​
  4. (D)34Q2C\dfrac{3}{4}\dfrac{Q^2}{C}43​CQ2​

Correct answer: (B)

Step-by-step solution →
Q122·PhysicsSingle correctJEE Main 2019
A parallel plate capacitor with plates of area 1 m2^{2}2 each, are at a separation of 0.1 m. If the electric field between the plates is 100 N/C, the magnitude of charge on each plate is:
  1. (A)7.85×10−107.85 \times 10^{-10}7.85×10−10 C
  2. (B)6.85×10−106.85 \times 10^{-10}6.85×10−10 C
  3. (C)8.85×10−108.85 \times 10^{-10}8.85×10−10 C
  4. (D)9.85×10−109.85 \times 10^{-10}9.85×10−10 C

Correct answer: (C)

Step-by-step solution →
Q123·PhysicsSingle correctJEE Main 2019
In the figure shown below, the charge on the left plate of the μ\muμF capacitor is −30μ-30\mu−30μC. The charge on the right place of the 6 μ\muμF capacitor is:
  1. (A)−12μ-12\mu−12μC
  2. (B)+12μ+12\mu+12μC
  3. (C)−18μ-18\mu−18μC
  4. (D)+18μ+18\mu+18μC

Correct answer: (D)

Step-by-step solution →
Q124·PhysicsSingle correctJEE Main 2019
Seven capacitors, each of the capacitance 2μF, are to be connected in a configuration to obtain an effective capacitance of (613)\left(\frac{6}{13}\right)(136​) μF. Which of the combinations, shown in figures below, will achieve the desired value?
  1. (A)(A)
  2. (B)(B)
  3. (C)(C)
  4. (D)(D)

Correct answer: (B)

Step-by-step solution →
Q125·PhysicsSingle correctJEE Main 2019
A parallel plate capacitor is of area 6 cm2^{2}2 and a separation 3 mm. The gap is filled with three dielectric materials of equal thickness (see figure) with dielectric constants K1_{1}1​ = 10, K2_{2}2​ = 12 and K3_{3}3​ = 14. The dielectric constant of a material which when fully inserted in above capacitor, gives same capacitance would be:
  1. (A)4
  2. (B)14
  3. (C)12
  4. (D)36

Correct answer: (C)

Step-by-step solution →
Q126·PhysicsSingle correctJEE Main 2019
A parallel plate capacitor is made of two square plates of side 'a', separated by a distance d(d <<a). The lower triangular portion is filled with a dielectric of dielectric constant K, as shown in the figure. Capacitance of this capacitor is
  1. (A)Kε0a22d(K+1)\frac{K\varepsilon_0 a^2}{2d(K+1)}2d(K+1)Kε0​a2​
  2. (B)Kε0a2d(K−1)ln⁡K\frac{K\varepsilon_0 a^2}{d(K-1)}\ln Kd(K−1)Kε0​a2​lnK
  3. (C)Kε0a2dln⁡K\frac{K\varepsilon_0 a^2}{d}\ln KdKε0​a2​lnK
  4. (D)12Kε0a2d\frac{1}{2}\frac{K\varepsilon_0 a^2}{d}21​dKε0​a2​

Correct answer: (B)

Step-by-step solution →
Q127·PhysicsSingle correctJEE Main 2019
A parallel palate capacitor with square plates is filled with four dielectrics of dielectric constants K1_11​, K2_22​, K3_33​, K4_44​ arranged as shown in the figure. The effective dielectric constant K will be:
  1. (A)K = (K1+K3)(K2+K4)K1+K2+K3+K4\dfrac{(K_1+K_3)(K_2+K_4)}{K_1+K_2+K_3+K_4}K1​+K2​+K3​+K4​(K1​+K3​)(K2​+K4​)​
  2. (B)K = (K1+K2)(K3+K4)2(K1+K2+K3+K4)\dfrac{(K_1+K_2)(K_3+K_4)}{2(K_1+K_2+K_3+K_4)}2(K1​+K2​+K3​+K4​)(K1​+K2​)(K3​+K4​)​
  3. (C)K = (K1+K2)(K3+K4)K1+K2+K3+K4\dfrac{(K_1+K_2)(K_3+K_4)}{K_1+K_2+K_3+K_4}K1​+K2​+K3​+K4​(K1​+K2​)(K3​+K4​)​
  4. (D)K = (K1+K4)(K2+K3)2(K1+K2+K3+K4)\dfrac{(K_1+K_4)(K_2+K_3)}{2(K_1+K_2+K_3+K_4)}2(K1​+K2​+K3​+K4​)(K1​+K4​)(K2​+K3​)​

Correct answer: (A)

Step-by-step solution →
Q128·PhysicsNumericalJEE Advanced 2018
Three identical capacitors C1C_{1}C1​, C2C_{2}C2​ and C3C_{3}C3​ have a capacitance of 1.0 μF1.0\ \mu F1.0 μF each and they are uncharged initially. They are connected in a circuit as shown in the figure and C1C_{1}C1​ is then filled completely with a dielectric material of relative permittivity ∈r\in_{r}∈r​. The cell electromotive force (emf) V0=8VV_{0} = 8VV0​=8V. First the switch S1S_{1}S1​ is closed while the switch S2S_{2}S2​ is kept open. When the capacitor C3C_{3}C3​ is fully charged, S1S_{1}S1​ is opened and S2S_{2}S2​ is closed simultaneously. When all the capacitors reach equilibrium, the charge on C3C_{3}C3​ is found to be 5μC5\mu C5μC. The value of ∈r=\in_{r} = ∈r​=__________.

Correct answer: 1.50

Step-by-step solution →
Q129·PhysicsSingle correctJEE Advanced 2017
PARAGRAPH 1 Consider a simple RC circuit as shown in Figure 1. Process 1: In the circuit the switch S is closed at t=0t = 0t=0 and the capacitor is fully charged to voltage V0V_{0}V0​ (i.e. charging continues for time T≫RCT \gg RCT≫RC). In the process some dissipation (ED)(E_{D})(ED​) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is ECE_{C}EC​. Process 2: In a different process the voltage is first set to V03\dfrac{V_{0}}{3}3V0​​ and maintained for a charging time T≫RCT \gg RCT≫RC. Then the voltage is raised to 2V03\dfrac{2V_{0}}{3}32V0​​ without discharging the capacitor and again maintained for time T≫RCT \gg RCT≫RC. The process is repeated one more time by raising the voltage to V0V_{0}V0​ and the capacitor is charged to the same final voltage V0V_{0}V0​ as in Process 1. These two processes are depicted in Figure 2. In Process 2, total energy dissipated across the resistance EDE_{D}ED​ is:
  1. (A)ED=12CV02E_{D} = \dfrac{1}{2}CV_{0}^{2}ED​=21​CV02​
  2. (B)ED=3(12CV02)E_{D} = 3\left(\dfrac{1}{2}CV_{0}^{2}\right)ED​=3(21​CV02​)
  3. (C)ED=13(12CV02)E_{D} = \dfrac{1}{3}\left(\dfrac{1}{2}CV_{0}^{2}\right)ED​=31​(21​CV02​)
  4. (D)ED=3CV02E_{D} = 3CV_{0}^{2}ED​=3CV02​

Correct answer: (C)

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Q130·PhysicsSingle correctJEE Advanced 2017
PARAGRAPH 1 Consider a simple RC circuit as shown in Figure 1. Process 1: In the circuit the switch S is closed at t=0t = 0t=0 and the capacitor is fully charged to voltage V0V_{0}V0​ (i.e. charging continues for time T≫RCT \gg RCT≫RC). In the process some dissipation (ED)(E_{D})(ED​) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is ECE_{C}EC​. Process 2: In a different process the voltage is first set to V03\dfrac{V_{0}}{3}3V0​​ and maintained for a charging time T≫RCT \gg RCT≫RC. Then the voltage is raised to 2V03\dfrac{2V_{0}}{3}32V0​​ without discharging the capacitor and again maintained for time T≫RCT \gg RCT≫RC. The process is repeated one more time by raising the voltage to V0V_{0}V0​ and the capacitor is charged to the same final voltage V0V_{0}V0​ as in Process 1. These two processes are depicted in Figure 2. In Process 1, the energy stored in the capacitor ECE_{C}EC​ and heat dissipated across resistance EDE_{D}ED​ are related by:
  1. (A)EC=EDE_{C} = E_{D}EC​=ED​
  2. (B)EC=EDln⁡2E_{C} = E_{D}\ln 2EC​=ED​ln2
  3. (C)EC=12EDE_{C} = \dfrac{1}{2}E_{D}EC​=21​ED​
  4. (D)EC=2EDE_{C} = 2E_{D}EC​=2ED​

Correct answer: (A)

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Q131·PhysicsMultiple correctJEE Advanced 2016
In the circuit shown below, the key is pressed at time t = 0. Which of the following statement(s) is (are) true?
  1. (A)The voltmeter displays – 5 V as soon as the key is pressed, and displays +5 V after a long time
  2. (B)The voltmeter will display 0 V at time t=ln⁡2t = \ln 2t=ln2 seconds
  3. (C)The current in the ammeter becomes 1/e1/e1/e of the initial value after 1 second
  4. (D)The current in the ammeter becomes zero after a long time

Correct answer: (A), (B), (C), (D)

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Q132·PhysicsMultiple correctJEE Advanced 2015
A parallel plate capacitor having plates of area S and plate separation d, has capacitance C1C_{1}C1​ in air. When two dielectrics of different relative permittivities (ε1=2\varepsilon_{1} = 2ε1​=2 and ε2=4\varepsilon_{2} = 4ε2​=4) are introduced between the two plates as shown in the figure, the capacitance becomes C2C_{2}C2​. The ratio C2C1\dfrac{C_{2}}{C_{1}}C1​C2​​ is
  1. (A)6/5
  2. (B)5/3
  3. (C)7/5
  4. (D)7/3

Correct answer: (D)

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Q133·PhysicsMultiple correctJEE Advanced 2014
A parallel plate capacitor has a dielectric slab of dielectric constant KKK between its plates that covers 1/31/31/3 of the area of its plates, as shown in the figure. The total capacitance of the capacitor is CCC while that of the portion with dielectric in between is C1C_1C1​. When the capacitor is charged, the plate area covered by the dielectric gets charge Q1Q_1Q1​ and the rest of the area gets charge Q2Q_2Q2​. The electric field in the dielectric is E1E_1E1​ and that in the other portion is E2E_2E2​. Choose the correct option/options, ignoring edge effects.
  1. (A)E1E2=1\frac{E_1}{E_2} = 1E2​E1​​=1
  2. (B)E1E2=1K\frac{E_1}{E_2} = \frac{1}{K}E2​E1​​=K1​
  3. (C)Q1Q2=3K\frac{Q_1}{Q_2} = \frac{3}{K}Q2​Q1​​=K3​
  4. (D)CC1=2+KK\frac{C}{C_1} = \frac{2+K}{K}C1​C​=K2+K​

Correct answer: (A), (D)

Step-by-step solution →
Q134·PhysicsMultiple correctJEE Advanced 2013
In the circuit shown in the figure, there are two parallel plate capacitors each of capacitance C. The switch S1S_{1}S1​ is pressed first to fully charge the capacitor C1C_{1}C1​ and then released. The switch S2S_{2}S2​ is then pressed to charge the capacitor C2C_{2}C2​. After some time, S2S_{2}S2​ is released and then S3S_{3}S3​ is pressed. After some time,
  1. (A)the charge on the upper plate of C1C_{1}C1​ is 2CV02CV_{0}2CV0​.
  2. (B)the charge on the upper plate of C1C_{1}C1​ is CV0CV_{0}CV0​.
  3. (C)the charge on the upper plate of C1C_{1}C1​ is 0.
  4. (D)the charge on the upper plate of C2C_{2}C2​ is −CV0-CV_{0}−CV0​.

Correct answer: (B), (D)

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Capacitors and Dielectrics — frequently asked

How many questions from Capacitors and Dielectrics appear in JEE?

Capacitors and Dielectrics has appeared in 115 of the last 186 JEE Main and JEE Advanced papers — about 62% of them — contributing 134 questions in total across those papers.

Is Capacitors and Dielectrics an important chapter for JEE?

Judged by how often it is actually tested, it appears in roughly 62% of papers. Chapters above about 50% are effectively guaranteed to show up every session, so they repay thorough preparation; lower-frequency chapters are better treated as targeted revision.

Where do these Capacitors and Dielectrics questions come from?

Every question is from an official JEE Main or JEE Advanced paper, transcribed from the original paper and tagged to this chapter. Answers follow the official answer key.

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