1. SI Unit of capacitance is ?

  1. Farad
  2. Henry
  3. Coulomb
  4. Ampere
View Answer

Answer: Option(A)


Memory: SI unit of capacitance is Farad, but practical unit is micro-farad.

2. The capacitance of a capacitor depends on ?

  1. The area of the plates
  2. The distance between the plates
  3. The dielectric material between them
  4. All of the above
View Answer

Answer: Option(D)


Memory: As per the capacitance formula, C = ϵ*A/d.

3. Dimensional formula of capacitance is ?

  1. M-1L-2T3I3
  2. M-2L-1T2I2
  3. M-1L-2T4I2
  4. M-1L-3T-2I-2
View Answer

Answer: Option(C)


Memory: As per the formula, F = kg-1m-2s4A2

4. The value of 1F in e.s.u is ?

  1. 3 × 1011
  2. 3 × 108
  3. 9 × 1011
  4. 1/3 × 10-10
View Answer

Answer: Option(C)


Memory: No information is available.

5. Which of the following acts as an open circuit for D.C and short circuit for A.C ?

  1. Inductor
  2. Resistor
  3. Capacitor
  4. Diode
View Answer

Answer: Option(C)


Memory: As we all know that, capacitive reactance of a capacitor depends on frequency.

Therefore, as per the formula Xc= 1/2πfc, when, frequency is zero (D.C), capacitive reactance is very high and acts as a open circuit.

And when frequency is greater than zero (A.C), capacitive reactance is low and acts as a short circuit.

6. What happens, if the plates of a charged capacitor are kept apart ?

  1. Decreases the capacitance
  2. Increases the capacitance
  3. Decreases the potential difference
  4. Increases the potential difference
View Answer

Answer: Option(D)


Memory: No information is available.

7. Capacity of a parallel plates capacitor can be increased by ?

  1. Increasing the distance between the plates
  2. Decreasing the distance between the plates
  3. Increasing the length of the plates
  4. Decreasing the thickness of the plates
View Answer

Answer: Option(B)


Memory: According to formula, C = ϵ*A/d.

Where,

  • C = Capacitance
  • ϵ = Permittivity of dielectric
  • A = Area of plates
  • d = Distance between the plates
equivalent capacitance between a and b

8. The equivalent capacitance between A and B in the above figure is ?

  1. 12 µF
  2. 14 µF
  3. 18 µF
  4. 25 µF
View Answer

Answer: Option(B)


Memory: As per the formula, (6*6*6/6+6+6)+2 = 14

parallel connection of capacitors

9. In the above figure, the two capacitors are connected in ?

  1. Series
  2. Parallel
  3. Series-parallel
  4. None of the above
View Answer

Answer: Option(B)


Memory: In the above figure, two capacitors are connected in parallel.

10. Four capacitors of value 3µF, 5µF, 7µF and 9µF are connected in parallel across a potential difference of 12V.

Their equivalent capacitance will be ?

  1. 20 µF
  2. 12 µF
  3. 6 µF
  4. 24 µF
View Answer

Answer: Option(D)


Memory: Parallel connection of capacitors are similar to series connection of resistors.

Therefore,

When capacitors are connected in parallel, the equivalent capacitance is the algebraic sum of their individual capacitance.

11. Capacitor stores which type of energy ?

  1. Mechanical energy
  2. Heat energy
  3. Gravitational energy
  4. Potential energy
View Answer

Answer: Option(D)


Memory: Capacitor stores potential energy.

The reciprocal of capacitance is called elastance.