Home
Class 12
PHYSICS
A magnetised needle of magnetic moment 3...

A magnetised needle of magnetic moment `3.6 xx 10^(-2) T^(-1)` is placed at `30^(@)` with the direction of uniform magnetic field of magnitude `2 xx 10^(-2)T`. Calculate the torque acting on the needle.

Text Solution

Verified by Experts

`tau = mu B sin theta `
Magnetic moment ` m = 3.6 xx 10^(-2) J T^(-1)`
Magnetic field `B = 2 xx 10^(-2) T`
Magnetic needle is inclined at an angle `theta = 30^(@)`
Torque `tau = ? `
` tau = 3.6 xx 10^(-2) xx 2 xx 10^(-2) sin 30^(@)`
` tau = 3.6 xx 10^(-4) ` Nm.
Promotional Banner

Similar Questions

Explore conceptually related problems

An electrle dipole with dipole moment 4 xx 10^(-9)Cm is aligned at 30^@ with the direction of a uniform clectric field of magnitude 5 xx 10^(4)NC^(-1) Calculate the magnitude of the torque acting on the dipole.

An electric dipole with dipole moment 4 xx 10^(-9) cm is kept at 30^@ with the direction of uniform electic field of magnitude 5 xx 10^4 NC^(-1) . The magnitude of torque on the dipole is

A bar magnet of magnetic moment 1.5 JT^(-1) lies aligned with the direction of a uniform magnetic field of 0.22 T . a . What is the amount of work required by an external torque to turn the magnet so as to align its magnetic moment : (i) normal to the direction , (ii) opposite to the field direction ? b. What is the torque on the magnet in cases (i) and (ii) ?

A square coil of side 10 cm consists of 20 turns and carries a current of 12 A. The coil is suspended vertically and the normal to the plane of the coil makes an angle of 30° with the direction of a uniform horizontal magnetic field of magnitude 0.8 T. What is the magnitude of the torque experienced by the coil?

A bar magnet having a magnetic moment of 1.0 xx 10^4 J T^(-1) is free to rotate in a horizontal plane. A horizontal magnetic field B = 4 xx 10^(-5) T exists in the space. Find the work done in rotating the magnet slowly from a direction parallel to the field to a direction 60^@ from the field.

A circular coil of radius 2.0 cm has 500 turns in it and carries a current of 1.0 A . Its axis makes an angel of 30^@ with the uniform magnetic field of 0f magnitude 0.40 T that exists in the space. Find the torque acting on the total.

Doubly ionized helium ions are projected with a speed of 10kms^(-1) in a direction perpendicular to a uniform magnetic field of magnitude 1.0 T. Find (a) the force acting on an ion, (b) the radius of the circle in which it ciruclates and ( c) the time taken by an ion to complete the circle.

A short bar magnet of magnetic moment 5.25xx10^(-2)JT^(-1) is placed with its axis perpendicular to the earth's field 's field direction . At what distance from the centre of the magnet the resultant field is inclined at 45^@ with earth's field on (a) its normal bisector and (b) its axis. Magnitude of te earth's field at the place is given to be 0.42 G, Ignore the length of the magnet in comparison to the distance involved.

A bar magnet with magnetic moment 2.5 xx10^3 J T^(-1) is rotating in horizontal plane in thespacecontaining magnetic induction B = 4xx10^(-5) T. The work done in rotating the magnet slowly from a direction parallel to the field to a direction 45^@ from the field,is (in joule)