Assertion (A): | An external force \(F\) is needed to be applied in the direction of the velocity \(v\) so that the loop can move with constant velocity \(v\). |
Reason (R): | As the loop moves towards the right, the magnetic flux decreases inducing an emf and a corresponding current. This current causes a retarding force to be exerted on the wire. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
1. | reducing relative motion between the core and magnet in an electric motor |
2. | by making the core of thin laminations |
3. | by increasing the conductor cross-sectional area |
4. | both (1) and (2) are correct |
Assertion (A): | A bar magnet is dropped into a long vertical copper tube. Even if air resistance is negligible, the magnet attains a constant terminal velocity. If the tube is heated, the terminal velocity increases. |
Reason (R): | The terminal velocity is independent of the eddy currents produced in the copper tube. |
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. |
Assertion (A): | Faraday's law of electromagnetic induction is a consequence of Biot-Savart's law. |
Reason (R): | Currents cause magnetic fields and interact with magnetic flux. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
Assertion (A): | Faraday's law of electromagnetic induction is not consistent with the law of conservation of energy. |
Reason (R): | Lenz's law is consistent with energy conservation. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
Statement I: | The magnetic field due to a very long current-carrying solenoid, at its centre, is inversely proportional to the radius of the solenoid, other things remaining constant. |
Statement II: | \(I\) is directly proportional to \(I^2.\) | The magnetic energy stored in a solenoid carrying a current
1. | Statement I is incorrect and Statement II is correct. |
2. | Both Statement I and Statement II are correct. |
3. | Both Statement I and Statement II are incorrect. |
4. | Statement I is correct and Statement II is incorrect. |
List-I | List-II | ||
(a) | \(\times\) current | inductance(i) | V |
(b) | \(\times\) capacitance | frequency(ii) | Wb |
(c) | \(\times\) magnetic flux | frequency(iii) | \(\Omega^{-1}\) |
(d) | electric flux | (iv) | V-m |
1. | (a)-(i), (b)-(iv), (c)-(ii), (d)-(iii) |
2. | (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv) |
3. | (a)-(iii), (b)-(i), (c)-(ii), (d)-(iv) |
4. | (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i) |
A rectangular loop and a circular loop are moving out of a uniform magnetic field region (as shown in the figure) to a field-free region with a constant velocity \(v.\) In which loop do you expect the induced emf to be constant during the passage out of the field region? The field is normal to the loops:
1. only in the case of the rectangular loop
2. only in the case of the circular loop
3. in both cases
4. none of these
In a coil of resistance \(10\) \(\Omega\), the induced current developed by changing magnetic flux through it is shown in the figure as a function of time. The magnitude of change in flux through the coil in Weber is:
1. \(2\)
2. \(6\)
3. \(4\)
4. \(8\)
Assertion (A): | Lenz's law is in accordance with the conservation of energy. |
Reason (R): | The amount of mechanical energy lost against the induced emf or current is equal to the electrical energy reappearing in the circuit. |
In the light of the above statements choose the correct answer from the options given below:
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. |