Q. No.Current in a circuit falls from \(5.0\) A to \(0\) A in \(0.1\) s. If an average emf of \(200\) V is induced, the self-inductance of the circuit is:
1. \(4\) H
2. \(2\) H
3. \(1\) H
4. \(3\) H
The back emf induced in a coil, when current changes from \(1\) ampere to zero in one milli-second, is \(4\) volts. The self-inductance of the coil is:
1. \(1~\text{H}\)
2. \(4~\text{H}\)
3. \(10^{-3}~\text{H}\)
4. \(4\times10^{-3}~\text{H}\)
| 1. | \(5\) H | 2. | \(2.5\) H |
| 3. | \(1.5\) H | 4. | \(2\) H |
A long solenoid has \(1000\) turns. When a current of \(4\) A flows through it, the magnetic flux linked with each turn of the solenoid is \(4\times 10^{-3}\) Wb. The self-inductance of the solenoid is:
1. \(3\) H
2. \(2\) H
3. \(1\) H
4. \(4\) H
| 1. | \(250\) J | 2. | \(125\) J |
| 3. | \(500\) J | 4. | \(100\) J |
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R):
| Assertion (A): | Self-inductance is called the inertia of electricity. |
| Reason (R): | It is on account of self-inductance that the coil opposes any change in current passing through it. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
The current \(i\) in an inductance coil varies with time \(t\) according to the graph shown in the figure. Which one of the following plots shows the variation of voltage in the coil with time?
| 1. |  |
2. |  |
| 3. |  |
4. |  |
The number of turns in a coil of wire of fixed radius & length is \(600\) and its self-inductance is \(108\) mH. The self-inductance of a coil of \(500\) turns will be:
1. \(74\) mH
2. \(75\) mH
3. \(76\) mH
4. \(77\) mH
A \(10\) H inductor carries a current of \(20\) A. How much ice at \(0^{\circ}\text{C}\) could be melted by the energy stored in the magnetic field of the inductor?
Latent heat of ice is \(2.26\times 10^{3}\) J/kg.
| 1. | \(0.08\) kg | 2. | \(8.8\) kg |
| 3. | \(0.88\) kg | 4. | \(0.44\) kg |
A coil is wound of a frame of rectangular cross-section. If the linear dimensions of the frame are doubled and the number of turns per unit length of the coil remains the same, then the self inductance increases by a factor of:
| 1. | \(6\) | 2. | \(12\) |
| 3. | \(8\) | 4. | \(16\) |
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