A parallel plate capacitor is made of circular plates each of radius \(R=6.0~\text{cm}\) has a capacitance \(C=100~\text{pF}.\) The capacitor is connected to a \(230~\text V\) AC supply with an (angular) frequency of \(300~\text{rad/s}.\) The amplitude of \(\vec{B}\) at the point \(3~\text{cm}\) from the axis between the plate is:
1. \(1.12\times 10^{-11}~\text T\)
2. \(2.01\times 10^{-12}~\text T\)
3. \(1.63\times 10^{-11}~\text T\)
4. \(1.01\times 10^{-12}~\text T\)
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. \( I_d=\dfrac{V_0}{\omega C} \sin \omega t \)
2. \( I_d=V_0 \omega C \sin \omega t \)
3. \( I_d=V_0 \omega C \cos \omega t \)
4. \( I_d=\dfrac{V_0}{\omega C} \cos \omega t\)
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 |
A parallel plate capacitor is charged by connecting it to a battery through a resistor. If \(i\) is the current in the circuit, then in the gap between the plates:
1. | A displacement current of magnitude equal to \(i\) flows in the same direction as \(i.\) |
2. | A displacement current of magnitude equal to \(i\) flows in the opposite direction to \(i.\) |
3. | A displacement current of magnitude greater than \(i\) flows but it 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 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. \(0.15~\text{A}\)