Figure shows a larger horizontal coil of radius R carrying a current I. Another small coil of radius `r(r lt lt R)` carrying a current i & N turns is placed at the centre with its plane at an angle `theta` from the axis. Find the torque experienced by the smaller coil in this situation.

A circular coil of n turns and radius r carries a current I. The magnetic field at the center is

A circular loop of radius R carries a current I. Another circular loop of radius r(ltltR) carries a current I. The plane of the smaller loop makes an angle of 30^@ with that of the larger loop. The planes of the two circles are at right angle to each other. Find the torque acting on the smaller loop.

A small coil of radius r is placed at the centre of another coaxial coil of radius R(Rgtgtr) find the coeffcient for this pair of coils.

A coil of radius R carries a current i_(1) . Another concentric coil of radius r (r lt lt R) carries a current i_(2) . Planes of two coils are mutually perpendicular and both the coils are free to rotate about common diameter. Find maximum kinetic energy attained by the two coils, when both are released from rest. The masses of two coils are M and m respectively. Strategy : The magnetic field due to coil of radius R is (mu_(0)i_(1))/(2R) . This field exerts a torque on shorter coil. An equal and opposite torque is exerted by the shorter coil on larger coil. There is no external torque acting on the system. The angular momentum remains conserved. Also the total mechanical energy remains conserved. At any instant, let omega_(1) and omega_(2) represent the angular velocity

A circular coil of radius R carries a current i . The magnetic field at its centre is B . The distance from the centre on the axis of the coil where the magnetic field will be B//8 is

A coil of radius R carries a current I . Another concentric coil of radius r (r lt lt R) carries current (1)/(2) . Initially planes of the two coils are mutually prependicular and both the coil are free to rotate about common diameter. They are released from rest from this position. The masses of the coils are M and m respectively. (m lt M) . During the subsequeny motion let K_(1) and K_(2) be the maximum kinetic energies of the two cells respectively. and let U be the magnetic of maximum potential energy of magnetic interaction of the system of the coils. Choose the correct options.

A coil of n turns and radius R carries a current I it is unwound and rewound to make a new coil of radius (R )/(2) and the same current is passed through it what is the ratio of the magnetic moment of the new coil and the original coil ?

A circular coil of radius r carries I. If the same coil is now changed into a square loop carrying the same current, magnitude of its magnetic moment will