Parallel Plate Capacitor Questions

Electric field is developed between the parallel plates of the capacitor when plates are connected across a battery. This setup is known as the parallel plate capacitor.

Parallel plate capacitor formula is

\(\begin{array}{l}C=k\epsilon _{0}\frac{A}{d}\end{array} \)
.

Read more: Parallel Plate Capacitor

Important Parallel Plate Capacitor Questions with Answers

1. Choose the correct answer: The two plates of parallel plate capacitors are ______

  1. Unequal in length
  2. Equal in length

Answer: b) Equal in length

Explanation: Parallel plates of the capacitor are equal in dimension.

2. Which relation is correct.

  1. Q ∝ 1/V
  2. Q ∝ 2V
  3. Q ∝ V
  4. Q ∝ V/2

Answer: c) Q ∝ V

Explanation: Q ∝ V since the potential difference between the two plates of a parallel plate capacitor is directly proportional to the number of electric charges stored in any of the plates.

3. Is mica a conducting material?

  1. YES
  2. NO

Answer: a) YES

Explanation: Mica is a non-conducting material.

4. The permittivity of space is _______

  1. 2.854 × 10−12 F/m
  2. 4.854 × 10−12 F/m
  3. 6.854 × 10−12 F/m
  4. 8.854 × 10−12 F/m

Answer: d) 8.854 × 10−12 F/m

Explanation: ϵo is the permittivity of space, and the value permittivity is 8.854 × 10−12 F/m.

5. The relative permittivity of dielectric material is represented by ______

  1. r
  2. p
  3. k
  4. d

Answer: c) k

Explanation: The ratio of the capacitance of a capacitor using that material as a dielectric, compared with a similar capacitor that has vacuum as its dielectric.

6. The parallel plate capacitor formula is _______

  1. \(\begin{array}{l}C=k\epsilon _{0}\frac{A}{d}\end{array} \)
  2. \(\begin{array}{l}C=k _{0}\frac{d}{A}\end{array} \)
  3. \(\begin{array}{l}C=k\epsilon _{0}+\frac{A}{d}\end{array} \)
  4. \(\begin{array}{l}C=k\epsilon _{0}-\frac{A}{d}\end{array} \)

Answer: a)

\(\begin{array}{l}C=k\epsilon _{0}\frac{A}{d}\end{array} \)

Explanation: The parallel plate capacitor is given by the formula

\(\begin{array}{l}C=k\epsilon _{0}\frac{A}{d}\end{array} \)
.

7. The relative permittivity for air is ______

  1. 1
  2. 2
  3. 4
  4. 6

Answer: a) 1

Explanation: The relative permittivity for air is 1.00058.

8. The capacitance for the parallel plate capacitor is _______

  1. \(\begin{array}{l}C=\frac{\varepsilon _{0}d}{A}\end{array} \)
  2. \(\begin{array}{l}C=\frac{V}{Q}= {\varepsilon _{0}A}+{d}\end{array} \)
  3. \(\begin{array}{l}C=\frac{V}{Q}= {\varepsilon _{0}A}-{d}\end{array} \)
  4. \(\begin{array}{l}C=\frac{Q}{V}=\frac{\varepsilon _{0}A}{d}\end{array} \)

Answer: d)

\(\begin{array}{l} C=\frac{Q}{V}=\frac{\varepsilon _{0}A}{d} \end{array} \)

Explanation: The capacitance for the parallel plate capacitor can be given as

\(\begin{array}{l} C=\frac{Q}{V}=\frac{\varepsilon _{0}A}{d}.\end{array} \)

9. Units of capacitance are ______

  1. Farad
  2. Pico-farads (pF)
  3. Micro-farads (µF)
  4. All the above options

Answer: d) All the above options

Explanation: Farads, micro-farads (µF), and pico-farads (pF) are the units of capacitance.

10. State true or false: The two conducting plates of parallel plate capacitors act as electrodes.

  1. True
  2. False

Answer: a) True

Explanation: The two conducting plates of parallel plate capacitors behave as electrodes and there is dielectric between the plates.

Practice Questions

  1. What is a capacitor?
  2. What are the types of capacitors?
  3. What is meant by a parallel plate capacitor?
  4. Define dielectric.
  5. Explain conducting and non-conducting materials with examples.

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