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 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
Vertical component of earth's magnetic field is zero at a place where angle of dip is
45o
90o
0o
60o
The angle of dip is 90o at
Earth's magnetic poles
Equator
Both (1) and (2 )
None of these
The dimensions of magnetic dipole moment will be
LA
ML-1 A
ML-1 A -2
L2 A
A bar magnet has a magnetic moment of 2.5 JT-1 and is placed in a magnetic field of 0.2 parallel to anti parallel position relative to the field direction is
Zero
0.5 J
2.0 J
1 J
A diamagnetic material in a magnetic field moves
Perpendicular to the field
From weaker to the stronger parts of the field
From stronger to the weaker parts of the field
In none of the above directions
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
Two bar magnets having same geometry with magnetic moment M and 2 M, are firstly placed in such a way that their similar poles are on the same side, then its period of oscillation is T1. Now the polarity of one of the magnets is reversed the time period of oscillations becomes T2. Then
T1 < T2
T1 > T2
T1 = T2
