Which of the following is the correct representation of magnetic field lines?
1. | (g), (c) | 2. | (d), (f) |
3. | (a), (b) | 4. | (c), (e) |
Which one of the following is correct?
1. | The magnetic field lines also represent the lines of force on a moving charged particle at every point. |
2. | Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid. |
3. | A bar magnet exerts a torque on itself due to its own field. |
4. | Magnetic field arises due to stationary charges. |
Diamagnetic material in a magnetic field moves:
1. | from stronger to the weaker parts of the field |
2. | from weaker to the stronger parts of the field |
3. | perpendicular to the field |
4. | in none of the above directions |
If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by \(\mu_d,~\mu_p,~\text{and}~\mu_f\) respectively, then:
1. \(\mu_p= 0 ~\text{and}~\mu_f \ne0\)
2. \(\mu_d\neq 0 ~\text{and}~\mu_p=0\)
3. \(\mu_d\ne 0 ~\text{and}~\mu_f \ne0\)
4. \(\mu_d= 0 ~\text{and}~\mu_p \ne0\)
For protecting a magnetic needle, it should be placed:
1. | In an iron box. |
2. | In a wooden box. |
3. | In a metallic box. |
4. | None of these. |
The correct direction of the magnetic field in the given figures is shown by:
1. | 2. | ||
3. | 4. |
1. | material \(A\) is preferred for making electromagnets. |
2. | material \(B\) is preferred for making permanent magnets. |
3. | material \(A\) is preferred for using electric generators and transformers. |
4. | all of these. |
1. | 2. | ||
3. | 4. |
1. | \((30\widehat k)\) N-m | 2. | \((10\widehat i+20\widehat j)\) N-m |
3. | \((20\widehat k)\) N-m | 4. | \((-30\widehat k)\) N-m |