The pole strength of a bar magnet is 48 ampere-metre and the distance between its poles is 25cm. The moment of the couple by which it can be placed at an angle of` 30^(@) `with the uniform magnetic intensity of flux density `0.15 "newton"//"ampere-metre"`

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . Use your answer to show that the magnetic flux density B between the poles of the magnet is 70 mT.

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . For the coil in the position for maximum torque, state whether the plane of the coil is parallel to, or normal to , the direction of the magnetic field.

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . For the coil in the position shown in the figure. calculate the magnitude of the force on (i) side AB of the coil and (ii) side BC of the coil.

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . The current in the coil in (a) is switched off and the coil s positioned as shown in the figure. The coil is then turned thorugh an angle of 90^@ in a time of 0.14 s. Calculate the average e.m.f. induced in the coil.

A bar magnet is 0.1 m long and its pole strength is 12 Am. Find the magnetic induction at a point on its axis at a distance of 0.2 m from its centre.

A bar magnet with poles 25 cm apart and of strength 14.4 amp - m rests with centre on a frictionless pivot. It is held in equilibrium aat an angle of 60^@ with respect to a uniform magnetic field of induction 0.25 Wb//m^(2) , by applying a force F at right angles to its axis at a point 10 cm from pivot. Calculate F.

A small coil is positionaed so that its axis lies along the axis of a large bar agnet, as shown in the figure. The coil has a cross-sectional area of 0.40 cm^2 and contains 150 turns of wire. The average magnetic flux density B through the coil aries with the distance x between the face of the magnet and the plane of the coil as shown in the figure. The coil is 5.0 cm from the face of the magnet to determine the magnetic flux density in the coil.

Two identical thin bar magnets, each of length L and pole strength m are placed at right angles to each other, with the N pole of one touching the S-pole of the other. Find the magnetic moment of the system.