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
A bar magnet of magnetic moment is placed in a magnetic field of induction . The torque exerted on it is
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
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. What is the value of n ?
2
1
0. 5
0 . 25
Due to the earth’s magnetic field, charged cosmic ray particles
can never reach the poles
can never reach the equator
require less kinetic energy to reach the equator than the poles
require greater kinetic energy to reach the equator, than the poles
The dimensions of magnetic dipole moment will be
LA
ML-1 A
ML-1 A -2
L2 A
Rate of change of torque with deflection θ is maximum for a magnet suspended freely in a uniform magnetic field of induction B when
θ = 45o
θ = 60o
θ = 0o
θ = 90o
A diamagnetic substance is brought near a strong magnet, then it is
attracted by a magnet
repelled by a magnet
repelled by north pole and attracted by south pole
attracted by north pole and repelled by south pole
According to Curie’s law, the magnetic susceptibility of a paramagnetic substance at an absolute temperature T is proportional to
T2
1/T
T
A bar magnet is placed with its north pole pointing earth’s north. The points of zero magnetic field will be which direction from the center of the magnet?
north and south
east and west
north-east and south-west
north-east and south-east
