A bar magnet of magnetic moment 104J/T is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from a direction parallel to a horizontal magnetic field of 4×10–5 T to a direction 60° from the field will be
1. 0.2 J 2. 2.0 J
3. 4.18 J 4. 2 × 102 J
Two equal bar magnets are kept as shown in the figure. The direction of the resultant magnetic field, indicated by arrowhead at the point \(P\) is: (approximately)
1. | 2. | ||
3. | 4. |
1. | equal pole strength |
2. | magnetic moment \(\frac{M}{4}\) |
3. | magnetic moment \(\frac{M}{2}\) |
4. | magnetic moment \(M\) |
A magnet of magnetic moment is placed along the x-axis in a magnetic field . The torque acting on the magnet is
1. 175 N-m
2. 150
3. 75 N-m
4. 25 N-m
1. Intersect at the neutral point
2. Intersect near the poles of the magnet
3. Intersect on the equatorial axis of the magnet
4. Do not intersect at all
The magnetic field lines due to a bar magnet are correctly shown in
1.
2.
3.
4. None of these
A bar magnet of length 3 cm has points A and B along its axis at distances of 24 cm and 48 cm on the opposite sides. Ratio of magnetic fields at these points will be
1. 8 2.
3. 3 4. 4
A dip needle in a plane perpendicular to magnetic meridian will remain
1. Vertical
2. Horizontal
3. In any direction
4. At an angle of dip to the horizontal
If the angles of dip at two places are 30o and 45o respectively, then the ratio of horizontal components of earth's magnetic field at the two places will be:
(Assume net magnetic field to be equal at the two places)
1. √3 : √2
2. 1 : √2
3. 1 : √3
4. 1 : 2
A line passing through places having zero value of magnetic dip is called
1. Isoclinic line
2. Agonic line
3. Isogonic line
4. Aclinic line