The torque on a current loop is zero if the angle between the positive normal and the magnetic field is either `theta =0` or `theta = 180^@`. In which of the two orientations, the equilibrim is stable?

Give the stability position of bar magnet for theta = 0^@, 180^@.

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?

If theta is angle between two vectors vec(a) and vec(b) then vec(a).vec(b)ge 0 only when …….

Derive an expression for the torque acting or a current carrying loop which subtends angle with uniform magnetic field.

(a) A current-carrying circular loop lies on a smooth horizontal plane. Can a uniform magnetic field be set up in such a manner that the loop turns around itself (i.e., turns about the vertical axis). (b) A current-carrying circular loop is located in a uniform external magnetic field. If the loop is free to turn, what is its orientation of stable equilibrium? Show that in this orientation, the flux of the total field (external field + field produced by the loop) is maximum. (c) A loop of irregular shape carrying current is located in an external magnetic field. If the wire is flexible, why does it change to a circular shape?

A straight horizontal conducting rod of length 0.45 m and mass 60 g is suspended by two vertical wires at its ends. A current of 5.0 A is set up in the rod through the wires. (a) What magnetic field should be set up normal to the conductor in order that the tension in the wires is zero? (b) What will be the total tension in the wires if the direction of current is reversed keeping the magnetic field same as before? (Ignore the mass of the wires.) g = 9.8 m s^(-2) .

Write an equation for the torque acting on a current carrying loop which subtends angle theta with uniform magnetic field.

Mention the angle between a current - carrying straight conductor and magnetic field for which the force experienced by the conductor placed in a magnetic field is maximum .

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 a 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 angle 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 .