Above curie temperature
A ferromagnetic substance becomes paramagnetic
A paramagnetic substance becomes diamagnetic
A diamagnetic substance becomes paramagnetic
A paramagnetic substance becomes ferromagnetic
A bar magnet of magnetic moment is placed in a magnetic field of induction . The torque exerted on it is
If a diamagnetic substance is brought near the north or the south pole of a bar magnet, it is
Repelled by both the poles
Repelled by the north pole and attracted by the south pole
Attracted by the north pole and repelled by the south pole
Attracted by both the poles
The work done in turning a magnet of magnetic moment M by an angle of 90o from the meridian, is n times the corresponding work done to turn it through an angle of 60o. The value of n is given by
2
1
0.5
0.25
A bar magnet having a magnetic moment of 2 × 10 4 JT -1 is free to rotate in a horizontal plane. A horizontal magnetic field B = 6 × 10-4 T exists in the space. The work done in taking the magnet slowly from a direction parallel to the field to a direction 60o from the field is
0.6 J
12 J
6 J
2 J
The angle of dip is 90o at
Earth's magnetic poles
Equator
Both (1) and ( 2)
None of these
For protecting a sensitive equipment from the external magnetic field, it should be
Placed inside an aluminium can
Placed inside an iron can
Wrapped with insulation around it when passing current through it
Surrounded with fine copper sheet
According to Curie’s law, the magnetic susceptibility of a paramagnetic substance at an absolute temperature T is proportional to
T2
1/T
T
Vertical component of earth's magnetic field is zero at a place where angle of dip is
45o
90o
0o
60o
Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show
Paramagnetism
Anti-ferromagnetism
No magnetic property
Diamagnetism
