A parallel plate capacitor made of circular plates each of radius \(R=6.0\) cm has a capacitance \(C=100\) pF. The capacitor is connected to a \(230\) V AC supply with an (angular) frequency of \(300\) rad/s. The amplitude of \(\vec{B}\) at the point \(3\) cm from the axis between the plate is:
1. | \(1.12\times 10^{-11}\) T | 2. | \(2.01\times 10^{-12}\) T |
3. | \(1.63\times 10^{-11}\) T | 4. | \(1.01\times 10^{-12}\) T |
Displacement current goes through the gap between the plates of a capacitor when the charge of the capacitor:
(a) | increases |
(b) | decreases |
(c) | does not change |
(d) | is zero |
Displacement current through a capacitor at a steady state is:
1. infinite
2. zero
3. \(\dfrac{\varepsilon_0d\phi_E}{dt}\)
4. \(\dfrac{\varepsilon_0d\phi_B}{dt}\)
A capacitor of capacitance \(C\) is connected across an AC source of voltage \(V\), given by;
\(V=V_0 \sin \omega t\)
The displacement current between the plates of the capacitor would then be given by:
1. \( I_d=\frac{V_0}{\omega C} \sin \omega t \)
2. \( I_d=V_0 \omega C \sin \omega t \)
3. \( I_d=V_0 \omega C \cos \omega t \)
4. \( I_d=\frac{V_0}{\omega C} \cos \omega t\)
A parallel plate capacitor of capacitance \(20~\mu\text{F}\) is being charged by a voltage source whose potential is changing at the rate of \(3~\text{V/s}.\) The conduction current through the connecting wires, and the displacement current through the plates of the capacitor would be, respectively:
1. zero, zero
2. zero, \(60~\mu\text{A}\)
3. \(60~\mu\text{A},\) \(60~\mu\text{A}\)
4. \(60~\mu\text{A},\) zero
1. | displacement current of magnitude equal to \(i\) flows in the same direction as \(i\). |
2. | displacement current of magnitude equal to \(i\) flows in a direction opposite to that of \(i\). |
3. | displacement current of magnitude greater than \(i\) flows but can be in any direction. |
4. | there is no current. |
1. | when an electric field is changing in the circuit. |
2. | when an electric field is constant. |
3. | when an electric field is absent. |
4. | always exists independent of the electric field. |
A capacitor is made of two circular plates each of radius \(12~\text{cm}\) and separated by \(5.0~\text{cm}\). The capacitor is being charged by an external source. The charging current is constant and equal to \(0.15~\text{A}\). The displacement current across the plates is:
1. \(0\)
2. \(0.14~\text{A}\)
3. \(0.16~\text{A}\)
4. \(0.15~\text{A}\)