A compass needle is placed in the gap of a parallel plate capacitor. The capacitor is connected to a battery through a resistance. The compass needle:
1. | does not deflect. |
2. | deflects for a very short time and then comes back to the original position. |
3. | deflects and remains deflected as long as the battery is connected. |
4. | deflects and gradually comes to the original position in a time which is large compared to the time constant. |
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 |
A capacitor of capacitance CC is connected across an AC source of voltage VV, given by;
V=V0sinωtV=V0sinωt
The displacement current between the plates of the capacitor would then be given by:
1. Id=V0ωCsinωtId=V0ωCsinωt
2. Id=V0ωCsinωtId=V0ωCsinωt
3. Id=V0ωCcosωtId=V0ωCcosωt
4. Id=V0ωCcosωtId=V0ωCcosωt
(A) | a varying sinusoidal current flowing through a capacitor |
(B) | an electric dipole, whose size (and magnitude) is oscillating with time |
(C) | a steady current flowing through a toroid |
1. | only (A) |
2. | only (B) |
3. | only (A) & (B) |
4. | (A), (B), (C) |
Statement I: | Charged particles which undergo acceleration or deceleration radiate their energy away. |
Statement II: | Therefore, charged particles moving in circular paths in a uniform magnetic field should also radiate their energy. |
1. | Statement I is true, Statement II is true and Statement I implies Statement II. |
2. | Statement I is true, Statement II is true and Statement I does not imply Statement II. |
3. | Statement I is true, Statement II is false. |
4. | Statement I is false, Statement II is true. |
Out of the following options which one can be used to produce a propagating electromagnetic wave?
1. | a stationary charge. |
2. | a chargeless particle. |
3. | an accelerating charge. |
4. | a charge moving at constant velocity. |
Assume a bulb of efficiency 2.5% as a point source. The peak values of the electric field and magnetic field produced by the radiation coming from a 100 W bulb at a distance of 3 m are respectively:
1. | 2.5 V/m, 2.2×10−8 T |
2. | 3.6 V/m, 3.6 T |
3. | 4.07 V/m, 1.4×10−8 T |
4. | 4.2 V/m, 3.4×10−6 T |
1. | 2.16 cm,24.1 GHz | 2. | 0.29 cm,13.7 GHz |
3. | 3.23 cm,20.0 GHz | 4. | 1.26 cm,23.9 GHz |
1. | E0√2 | 2. | E0 |
3. | √2E0 | 4. | √3E0 |