Moving Charges And Magnetism

Two wires and are of lengths and . is bent into a circle of radius and into an arc of radius . A current is passed through and through . To have the same magnetic inductions at the centre, the ratio of is

In a moving coil galvanometer, to make the field radial

The relation connecting magnetic susceptibility and relative permeability is

Magnetic field at the centre of a coil in the form of a square of side carrying a current of is

Ampere's circuital law is equivalent to

A turn closely wound circular coil of radius carries a current of . The magnetic moment of the coil is, approximately

A rectangular coil, of sides and respectively, has turns in it. It carries a current of , and is placed in a uniform magnetic field of in such a manner that its plane makes an angle with the field direction. The torque on the loop is

An electron and a proton, both having the same kinetic energy, enter a region of uniform magnetic field, in a plane perpendicular to the field. If their masses are denoted by and respectively, then the ratio of the radii (electron to proton) of their circular orbits is

Three coplanar, parallel, long straight wires are equally spaced, that is, the distance between each pair of successive wires is the same. The first and the third wire carry currents of each, in the same direction. What must be the current in the second wire (wire in the middle), so that the other two wires do not feel any net force?

A long straight wire is carrying a current of . The magnetic field at a distance of is

A straight wire of mass and length carries a current of . It is suspended in mid-air by a uniform horizontal magnetic field . What is the magnitude of the magnetic field?

A solenoid of length has a radius of and is made up of turns. It carries a current of . What is the magnitude of the magnetic field inside the solenoid?

In a moving coil galvanometer, the coil having turns and an average area of carries a current of and is set parallel to a magnetic field with a torque of . The strength of the magnetic field is

A very long conductor carries a current of . The magnetic field at a point whose distance is from one end of the conductor is (in )