A small magnet of magnetic moment M is placed at broad side on position of a magnet of magnetic M', length 2l' in such a way that the axis of former coincides with the perpendicular bisector of the latter. The separation between their centres is d. Calculate the nature of interaction (force or couple ) among them. What is its limiting value, when d becomes very large ?

A small coil of radius 0.002 m is placed on the axis of a magnet of magnetic moment 10^(5) JT^(-1) and length 0.1 m at a distance of 0.15 m from the centre of the magnet. The plane of the coil is perpendicular to the axis of the magnet. Find the force on the when a current of 2.0 A is passed through it.

Derive an expression for the magnetic field due to magnetic dipole in broad-side on position at a distance r from its centre. The length of the dipole is 2 l and its magnetic moment is M.

Two bar magnets having same geometry with magnetic moments M and 2M, are firstly placed in such a way what their similar poles are same side then its time period of oscillation is T_1 . Now the polarity of one of the magnet is reversed then time period of oscillation will be

A small magnet A makes 10 vibrations in 90 seconds in earth's field. When another magnet B of short length is placed 0.1 m due south of the direction of earth's field, the magnet A makes 10 vibrations in 45 seconds . Calculate the magnetic moment of magnet B. Given B_(H)=0.3 G

A small magnet of magnetic moment pixx10^(-3) Am^(2) is placed on the Y-axis at a distance of 0.1 from the origin with its axis parallel to the X-axix. A coil have 169 turns and radius 0.05 m is placed on the X-axis at a distance of 0.12 m from the origin with the axis of the coil coinciding with the X-axis. Find the magnitude and direction of the current in the coil for a compass needle placed at the origin, to point in the north-south direction.

A bar magnet of magnetic moment M and moment of inertia I (about centre, perpendicular to length) is cut into two equal pieces, perpendicular to length. Let T be the period of oscillation of the original magnet about an axis through the mid point, perpendicular to length, in a magnetic field vecB . What would be the similar period T' for each piece?

A short bar magnet of magnetic movement 5.25 xx 10^-2 J T^-1 is placed with its axis perpendicular to the earth’s field direction. At what distance from the centre of the magnet, the resultant field is inclinedat 45^@ with earth’s field on its normal bisector. Magnitude of the earth’s field at the place is given to be 0.42 G. Ignore the length of the magnet in comparison to the distances involved.

A short bar magnet of magnetic movement 5.25 xx 10^-2 J T^1 is placed with its axis perpendicular to the earth’s field direction. At what distance from the centre of the magnet, the resultant field is inclined at 45^@ with earth’s field on its axis. Magnitude of the earth’s field at the place is given to be 0.42 G. Ignore the length of the magnet in comparison to the distances involved.

A short bar magnet is placed in a horizontal plane with its axis in the magnetic merdian . Null points are found on its equitorial line (i.e., its normal bisector) at 12.5 cm and the earth's magnetic field at the place is 0.38 G the angle of dip is zero. (i) What is the total magnetic field at points on the axis of the magnet located by the same distance (12.5 cm) as the null-points from the centre? (ii) Locate the null points when the magnet is turned around by 180^(@) . Assume that the length of the magnet is negligible as compared to the distance of the null-point from the centre of the magnet.