If H is the horizontal component of the earth's magnetic field and 'V' is the vertical component of the earth's magnetic field, then at the magnetic equator:
1. V and H are equal.
2. values of V and H are zero.
3. value of H is zero only.
4. value of V is zero only.
Two bar magnets are held together tightly in a vibration magnetometer. When their like poles are together, they make \(20\) oscillations per minute and when their unlike poles are together, they make \(8\) oscillations per minute. The ratio of the magnetic dipole moments of two bar magnets is:
1. \(29:21\)
2. \(6:15\)
3. \(1:6\)
4. \(25:4\)
The magnetic susceptibility \(\chi\) of a diamagnetic material depends on absolute temperature \(T\) as:
1. \(\chi \propto T\)
2. \(\chi \propto \frac{1}{T}\)
3. \(\chi \propto T^0\)
4. \(\chi \propto \frac{1}{\sqrt{T}}\)
The magnetic lines of force inside a bar magnet are:
1. | from south to the north pole. |
2. | from north to the south pole. |
3. | not present. |
4. | intersecting each other. |
The material which is used to make permanent magnet has:
1. | High retentivity, low coercivity |
2. | Low retentivity, low coercivity |
3. | Low retentivity, high coercivity |
4. | High retentivity, high coercivity |
An electric cable is carrying current from north to south. The position of the null point from the cable is:
1. Vertically upward
2. Vertically downward
3. Eastward
4. Nowhere
Which of the following graphs represents the correct variation of the intensity of magnetisation (I) with the intensity of the magnetising field (H) in a ferromagnetic substance?
1. | 2. | ||
3. | 4. |
The magnetic susceptibility χ of a ferromagnetic material varies with temperature, as:
1. | 2. | ||
3. | 4. |
Which of the following is not dimensionless?
(where symbols stand for their usual meanings in magnetism)
1. \(\frac{I}{H}\)
2. \(\frac{B}{\mu_0H}\)
3. \(\mu_r\)
4. \(\frac{\mu_r B}{H}\)
At a place, the angle of dip is 30. If the horizontal component of the earth's magnetic field is B, the total intensity is:
1.
2.
3. 2B
4. B