An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 A m-1. The permeability of the material of the rod is:
At point A on the earth's surface, the angle of dip is, . At a point B on the earth's surface, the angle of dip is, . We can interpret that:
1. A and B are both located in the southern hemisphere.
2. A and B are both located in the northern hemisphere.
3. A is located in the southern hemisphere and B is located in the northern hemisphere.
4. A is located in the northern hemisphere and B is located in the southern hemisphere.
The relation amongst the three elements of Earth's magnetic field, namely horizontal component H, vertical component V and dip angle is: (=total magnetic field)
1. V=tan, H=
2. V=sin, H=cos
3. V=cos, H=sin
4. V=, H=tan
A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched on, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence the rod gains gravitational potential energy. The work required to do this comes from:
|1.||the current source|
|2.||the magnetic field|
|3.||the lattice structure of the material of the rod|
|4.||the induced electric field due to the changing magnetic field.|
If and be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip is given by:-
A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in the equilibrium state. The energy required to rotate it by 60o is W. Now the torque required to keep the magnet in this new position is:
The following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole. Which configuration has the highest net magnetic dipole moment?
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:
A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It
1. will become rigid showing no movement
2. will stay in any position
3. will stay in north-south direction only
4. will stay in east-west direction only