Capacitor questions with solutions

Showing 1–10 of 258 questions

• MCQmediumCapacitor

  Capacitors C and 2C are connected in parallel and charged to potential V. The battery is removed and a dielectric of constant K is inserted fully into capacitor C. The final potential across each capacitor is:

  Options

  • Option A

    V/(K+2)

  • Option B

    2V/(K+2)

  • Option C

    3V/(K+2)

  • Option D

    (K+2)/(3V)

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• NumericmediumCapacitor

  Three identical capacitors C₁, C₂ and C₃, each 1.0 µF, are initially uncharged and connected as shown. C₁ is completely filled with a dielectric of relative permittivity εᵣ. The cell emf is V₀ = 8 V. First S₁ is closed while S₂ remains open. After C₃ is fully charged, S₁ is opened and S₂ is closed simultaneously. At final equilibrium, the charge on C₃ is 5 µC. Find εᵣ.

  

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  JEE Advanced 2018

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• MCQmediumCapacitor

  Two conducting objects carrying charges +Q and -Q are placed on the x-axis at x = 0 and x = 1 respectively. The electric field on the x-axis is E(x) = 3Q(x² + 4/3). If the capacitance of this configuration is C, find 1/C (in F⁻¹).

  Options

  • Option A

    2

  • Option B

    3

  • Option C

    5

  • Option D

    7

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• MCQeasyCapacitorRC circuit

  During charging of a 2.5 μF capacitor in a DC circuit, the displacement current is 0.25 mA. Find the rate of change of capacitor voltage dV/dt.

  Options

  • Option A

    1 V s⁻¹

  • Option B

    10 V s⁻¹

  • Option C

    100 V s⁻¹

  • Option D

    0.1 V s⁻¹

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  JEE Mains 2025 23 Jan Evening Shift

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• MCQmediumCapacitor

  Both capacitors are initially uncharged and then connected as shown and switch is closed. What is the potential difference across the 3 µF capacitor ?

  

  Options

  • Option A

    30 V

  • Option B

    10 V

  • Option C

    25 V

  • Option D

    None of these

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• MCQmediumCapacitor

  A capacitor of capacitance C is charged to a potential difference V from a cell and then disconnected. A charge +Q is now given to its positive plate. The potential difference across the capacitor is now:

  Options

  • Option A

    V

  • Option B

    V + Q/C

  • Option C

    V + Q/(2C)

  • Option D

    V - Q/C

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• MCQmediumCapacitor

  Five conducting plates are placed face to face and equally spaced by distance d. The area of each plate is half that of the previous plate. If the area of the first plate is A, find the equivalent capacitance of the system shown.

  

  Options

  • Option A

    ε₀A/d

  • Option B

    ε₀A/(10d)

  • Option C

    ε₀A/(20d)

  • Option D

    ε₀A/(30d)

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• MCQeasyCapacitorparallel plate capacitor ,cylindrical capacitor and spherical capacitor

  A parallel-plate capacitor initially has l=3 cm, b=1 cm and d=3 μm. Which changes increase its capacitance by a factor 10? A: l=6 cm,b=5 cm,d=3 μm; B: l=5 cm,b=2 cm,d=1 μm; C: l=5 cm,b=1 cm,d=30 μm; D: l=1 cm,b=1 cm,d=30 μm.

  Options

  • Option A

    A, B

  • Option B

    A, C

  • Option C

    B, C

  • Option D

    B, C, D

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  JEE Mains 2025 24 Jan Morning Shift

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• MCQmediumCapacitor

  A parallel-plate capacitor consists of two circular plates separated by 5 mm with dielectric constant 2.2 between them. When the electric field in the dielectric is 3×10⁴ V/m, the positive-plate charge density is closest to:

  Options

  • Option A

    6×10⁻⁷ C/m²

  • Option B

    3×10⁻⁷ C/m²

  • Option C

    3×10⁴ C/m²

  • Option D

    6×10⁴ C/m²

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• Multi-correctmediumCapacitor

  Four capacitors and a battery are connected as shown. The potential drop across the 7 μF capacitor is 6 V. Which statements are correct?

  Select all that apply

  • Option A

    Potential difference across the 3 μF capacitor is 10 V.

  • Option B

    Charge on the 3 μF capacitor is 42 μC.

  • Option C

    The emf of the battery is 30 V.

  • Option D

    Potential difference across the 12 μF capacitor is 10 V.

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