Assertion (A): | Work done by magnetic force on a charged particle moving in a uniform magnetic field is zero. |
Reason (R): | Path of a charged particle in a uniform magnetic field, projected in the direction of field, will be a straight line. |
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): | \(\alpha\)-particle enter in a uniform magnetic field perpendicularly with the same speed, the time period of revolution of \(\alpha\)-particle is double to that of a proton. | If a proton and an
Reason (R): | In a magnetic field, the period of revolution of a charged particle is directly proportional to the charge of the particle and inversely proportional to the mass of the particle. |
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): | Magnetic field interacts with a moving charge and not with a stationary charge. |
Reason (R): | A moving charge produces a magnetic field, which interacts with another magnetic field. |
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): | If a charged particle is moving on a circular path in a perpendicular magnetic field, the momentum of the particle is not changing. |
Reason (R): | The velocity of the particle is not changing in the magnetic field. |
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. |
Given below are two statements:
Assertion (A): | A uniformly moving charged particle in a uniform magnetic field, may follow a path along magnetic field lines. |
Reason (R): | The direction of the magnetic force experienced by a charged particle is perpendicular to its velocity and magnetic field.- |
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. |
Statement I: | A charged particle moving in a magnetic field experiences a force which is zero only when it moves in the direction of the field or against it. |
Statement II: | Whenever a charged particle moves in a uniform magnetic field, its trajectory may be a circle, a straight line or a helix. |
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. |
A particle having a mass of \(10^{-2}\) kg carries a charge of \(5\times 10^{-8}~\mathrm{C}\). The particle is given an initial horizontal velocity of \(10^5~\mathrm{ms^{-1}}\) in the presence of electric field \(\vec{E}\) and magnetic field \(\vec{B}\) . To keep the particle moving in a horizontal direction, it is necessary that:
(a) | \(\vec{B}\) should be perpendicular to the direction of velocity and \(\vec{E}\) should be along the direction of velocity. |
(b) | Both \(\vec{B}\) and \(\vec{E}\) should be along the direction of velocity. |
(c) | Both \(\vec{B}\) and \(\vec{E}\) are mutually perpendicular and perpendicular to the direction of velocity |
(d) | \(\vec{B}\) should be along the direction of velocity and \(\vec{E}\) should be perpendicular to the direction of velocity. |
Which one of the following pairs of statements is possible?
1. | (c) and (d) |
2. | (b) and (c) |
3. | (b) and (d) |
4. | (a) and (c) |