Magnetism and M...

An iron rod of volume 10^–4 m³ and relative permeability 1000 is placed inside a long solenoid wound with 5 turns/cm. If a current of 0.5 A is passed through the solenoid, then the magnetic moment of the rod is

A bar magnet has coercivity 4 × 10³ Am^–1. It is desired to demagnetize it by inserting it inside a solenoid 12 cm long and having 60 turns. The current that should be sent through the solenoid is

A magnet is suspended in the magnetic meridian with an untwisted wire. The upper end of wire is rotated through 180° to deflect the magnet by 30° from magnetic meridian. When this magnet is replaced by another magnet, the upper end of wire is rotated through 270° to deflect the magnet 30° from magnetic meridian. The ratio of magnetic moments of magnets is

A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be 2 seconds. The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be 2 seconds. Then the angle of dip is

The unit for molar susceptibility is

A solenoid has core of a material with relative permeability 500 and its windings carry a current of 1 A. The number of turns of the solenoid is 500 per metre. The magnetization of the material is nearly

For substances hysteresis (B–H) curves are given as shown in figure. For making temporary magnet which of the following is best

A curve between magnetic moment and temperature of magnet is

The variation of magnetic susceptibility ( χ ) with temperature for a diamagnetic substance is best represented by

The variation of magnetic susceptibility ( χ ) with magnetizing field for a paramagnetic substance is