Interstellar space has an extremely weak magnetic field of the order of `10^(-12)T.` Can such a weak fleld be of any significant consequence? Explain.

A rectangular coil of 300 turns has an area of 25 cm x 10 cm. The coil rotates with a speed of 50 cps in a uniform magnetic field of strength 4 xx 10^(-2)T about an axis perpendicular to the field. The peak value of the induced e.m.f is (in volt)

A square loop of side 12 cm with its sides parallel to X and velocity of 8 cm s in the positive x-direction in an environment containing a magnetic field in the positive z-direction. The field is neither uniform in space nor constant in time. It has a gradient of 10 T cm along the negative x-direction (that is it increases by 103 T cm- as one moves in the negative x-direction), and it is decreasing in time at the rate of 103 Ts. Determine the direction and magnitude of the induced current in axes is moved with a the loop if its resistance is 4.50 m2. Sol. Given, side of loop a = 12 cm . Area of loop (A) = a = (12) = 144 cm = 144 x 10 m? (. Area of square = (side))

A 100 turn closely wound circular coil of radius 10 cm carries a current of 3.2.A. (a) What is the field at the centre of the coil ? (b) What is the magnetic moment of this coil ? The coil is placed in vertical plane and is free to rotate about a horizontal axis which coincides with its diameter. A uniform magnetic field of 2T in the horizontal direction exists such that initially the axis of the coil is in the direction of the field. The coil rotates through an anlge of 90^(@) under the influence of the magnetic field. (c) What are the magnitudes of the torques on the coil in the initial and final position ? (d) What is the angular speed acquired by the coil when it has rotated by 90^(@) ? The moment of inertia of the coil is 0.1 kg m^(2)

A magnetic dipole is under the influence of two magnetic fields. The angle between the field directions is 60^(@) , and one of the fields has a magnitude of 1.2 xx 10^(-2)T . If the dipole comes to stable equilibrium at an angle of 15^(@) with this field, what is the magnitude of the other field ?

The earth's field, it is claimed, roughly approximates the field due to a dipole to magnetic moment 8 xx 10^(22) J T^(-1) located at its centre. Check the order of magnitude of this number in some way.

A jet plane is travelling towards west at a speed of 1800 km/h. What is the voltage difference developed between the ends of the wing having a span of 25 m, if the Earth's magnetic field at the location has a magnitude of 5 xx 10^(-4)T and the dip angle is 30^(@).