The following figures show the arrangement of bar magnets in different configurations. Each magnet has a magnetic dipole. Which configuration has the highest net magnetic dipole moment?
1. | 2. | ||
3. | 4. |
A bar magnet of length \(‘l’\) and magnetic dipole moment \(‘M’\) is bent in the form of an arc as shown in the figure. The new magnetic dipole moment will be:
1. | \(\frac{3M}{\pi}\) | 2. | \(\frac{2M}{l\pi}\) |
3. | \(\frac{M}{ 2}\) | 4. | \(M\) |
A vibration magnetometer placed in a magnetic meridian has a small bar magnet. The magnet executes oscillations with a time period of 2 s in the earth's horizontal magnetic field of 24 T. When a horizontal field of 18 T is produced opposite to the earth's field by placing a current-carrying wire, the new time period of the magnet will be:
1. 1 s
2. 2 s
3. 3 s
4. 4 s
Two identical bar magnets are fixed with their centres at a distance d apart. A stationary charge Q is placed at P in between the gap of the two magnets at a distance D from the centre O as shown in the figure:
The force on the charge Q is in:
1. direction along OP
2. direction along PQ
3. direction perpendicular to the plane of paper
4. zero
A bar magnet is oscillating in the Earth's magnetic field with a period T. What happens to this period and motion if this mass is quadrupled:
1. | motion remains S.H.M. with time period = T/2 |
2. | motion remains S.H.M. with time period = 2T |
3. | motion remains S.H.M. with time period = 4T |
4. | motion remains S.H.M. with time and period remains nearly constant |
Two bar magnets having the same geometry with magnetic moments M and 2M are firstly placed in such a way that if their similar poles are on the same side then their time period of oscillation is T1. Now if the polarity of one of the magnets is reversed then the time period of oscillation is T2. The relation between T1 & T2 is:
1.
2.
3.
4.
For a vibration magnetometer, the time period of the suspended bar magnet can be reduced by:
1. moving it towards the south pole
2. moving it towards the north pole
3. moving it towards the equator
4. anyone of them