A short bar magnet placed with its axis at `30^(@)` with a uniform external magnetic field of 0.25T. T experiences a torque of magnitude equal to `4.5 xx 10^(-2)J`. What is the magnitude of magntic moment of the magnet?

A short bar magnet placed with its axis at 30^@ with an extemal field of 800 G experiences a tunque of 0.016 Nm, (a) What is the magnetic moment of the magnet? (b) What is the work done in moving it from its most stable to most unstable position? (c) The bar magnet is replaced by a solenoid of cros B-sectional area 2 xx 10^(-4) m^(2) and 1000 tums, but of the same magnetic moment. Determine the current flowing through the solenoid.

An electric dipole with dipole moment 4xx10^(-9) cm is aligned at 30^(@) with the direction of a uniform electric field of magnitude 5xx10^(4)NC^(-1) . Calculate the magnitude of the torque acting on the dipole.

A square coil of side 10 cm consists of 20 turns and carries a current of 12A. The coil is suspended vertically and normal to the plane of the coil, makes an angle of 30^(@) with the direction of a uniform horizontal magnetic field of magnitude 0.80T. What is the magnitude of torque experienced by the coil?

A bar magnet of magnetic moment 1.5 JT^(-1) lies aligned with the direction of a uniform magnetic field of 0.22 T. (a) What is the amount of work required by an external torque to turn the magnet so as to align its magnetic moment: (i) normal to the field direction (ii) opposite to the field direction? (b) What is the torque on the magnet in cases (i) and (ii)?

A paramagentic sample shows a net magnetization of 8 Am^(-1) when placed in an external magentic field of 0.6 T at a temperature of 4 k .When the same sample is placed in a external magnetic field of 0.2 T at temperature of 16 K . The magnetization will be .

A proton of energy 8 MeV enters a uniform magnetic field of 5T at right angles to the field. What is the magnetic force acting on proton ?

A magnetic needle has a magnetic moment 5xx 10^(-2) "Am"^(2) . If the moment of inertia of a magnet about an axis passing through the centre and perpendicular to the length of a magnet is 1.0 xx 10^(-7)"kgm"^(2) then calculate the magnitude of the magnetic field which sets the magnet into oscillation at a frequency of 2 Hz.