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
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
Vertical component of earth's magnetic field is zero at a place where angle of dip is
45o
90o
0o
60o
The dimensions of magnetic dipole moment will be
LA
ML-1 A
ML-1 A -2
L2 A
The angle of dip is 90o at
earth's magnetic poles
equator
both (a ) and ( b )
8 times
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
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
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
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 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