The dimensions of magnetic dipole moment will be
LA
ML-1 A
ML-1 A -2
L2 A
A bar magnet is oscillating in earth’s magnetic field with a period T. What happen to its period of motion, if its mass is quadrupled?
Motion remains simple harmonic with new period = T/2
Motion remains simple harmonic with new period = 2 T
Motion remains simple harmonic with new period = 4 T
Motion remains simple harmonic and the period stays nearly constant
A bar magnet has a magnetic moment of 2.5 JT-1 and is placed in a magnetic field of 0.2 parallel to antiparallel 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. The value of n is given by
2
1
0.5
0.25
The angle of dip is 90o at
earth's magnetic poles
equator
both (a ) and ( b )
None of these
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 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
Above curie temperature
a ferromagnetic substance becomes paramagnetic
a paramagnetic substance becomes diamagnetic
a diamagnetic substance becomes paramagnetic
a paramagnetic substance becomes ferromagnetic
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
According to Curie’s law, the magnetic susceptibility of a paramagnetic substance at an absolute temperature T is proportional to
T2
1/T
T
