Question Details

A capacitor of capacitance ‘C’, is connected across an ac source of voltage V, given by V=V0 sinωt The displacement current between the plates of the capacitor, would then be given by :

Options

A

Id = (V0/ωC) cosωt

B

Id = (V0/ωC) sinωt

C

Id = V0ωCsinωt

D

Id = V0ωCcosωt

Show Answer

Correct Answer :

Option D

Id = V0ωCcosωt

Id = V0ωCcosωt

Solution :

The correct option is Id = V0ωCcosωt.

Step-by-Step Explanation:

1. Understanding Capacitor and Voltage:
We are given a capacitor of capacitance C connected to an alternating voltage source. The voltage across the capacitor as a function of time t is given by:
V=V0sin(ωt)

2. Relation between Charge and Voltage:
The instantaneous charge q on the plates of the capacitor at any time t is related to the capacitance and the instantaneous voltage across it by the relation:
q=CV

Substituting the expression for V into the equation:
q=CV0sin(ωt)

3. Calculating the Displacement Current:
By definition, the displacement current Id between the plates of a capacitor is equal to the rate of change of charge on its plates, which is also equal to the conduction current in the wires. Mathematically:
Id=dqdt

Substitute the expression for q:
Id=ddt[CV0sin(ωt)]

Since C and V0 are constants, we can take them out of the derivative:
Id=CV0ddt[sin(ωt)]

4. Evaluating the Derivative:
Using the chain rule of differentiation, the derivative of sin(ωt) with respect to t is ωcos(ωt):
Id=CV0(ωcos(ωt))

Rearranging the terms, we get:
Id=V0ωCcos(ωt)

Thus, the displacement current between the plates of the capacitor is given by Id=V0ωCcos(ωt).

Unlock Our Free Library

Access expert-curated educational resources and study materials—completely free.

Discover more resources

You may also like

Mock Tests

View All
  • JEE
  • intermediate
  • 3 hours
  • chemistry, mathematics, physics
  • Proctored

  • JEE
  • intermediate
  • 3 hours
  • chemical engineering, mathematics, physics

Ask AI Tutor
5 left
Q1 View Question & Options
AI Tutor is solving this question...
Reading question context & options...