Magnetism

A bar magnet of magnetic moment 80 units is cut into two halves of equal length: the magnetic moment of each half will be

• 80 units

• 40 units

• 60 units

• 20 units

A thin bar magnet of length 2L is bent at the midpoint so that the angle between them is 60⁰. The new length of the magnet is :

• (2)^1/2 L

• (3)^1/2 L

• 2L

• L

A semi circular magnet of moment M is being straightened , then the new magnetic moment :

• (2M/Π)

• Π / 2 M

• ( M Π / 2)

• (3M / Π)

The ratio of magnetic flux density to the strength of magnetising field is called :

• Magnetic potential

• Magnetic permeability

• Magnetic susceptibility

• Magnetic hysteresis

The dip angle at the magnetic poles :

• 0⁰

• 90⁰

• 45⁰

• 60⁰

The temperature at and above which a ferromagnetic material becomes a paramagnetic is called:

• critical temperature

• inversion temperature

• curie temperature

• debye temperature

A hydrogen atom is paramagnetic , a Hydrogen molecule is a :

• diamagnetic

• paramagnetic

• ferromagnetic

• anti-ferromagnetic

The angle between the earth's magnetic and geographic axes is :

• zero

• 17⁰

• 23⁰

• 71⁰

The unit of magnetic susceptibility is :

• henry

• amp / m

• weber / m

• none of these

A sphere of gold is brought close to a powerful magnet . The sphere will experience?

• zero force

• Repulsive force

• Attractive force

• Oscillating force