A long straight metal rod has a very long hole of radius `'a'` drilled parallel to the rod axis as shown in the figure. If the rod carries a current `I`, find the magnetic field on axis of hole. Given `C` is the centre of the hole and `OC=c`.

A long straight metal rod has a very long hole of radius a drilled parallel to rod as shown in the figure. If the rod carries a current i . Find the magnetic field (a) on the axis of the rod. (b) on the axis of the hole.

A long solenoid has a radius a and number of turns per unit length is n . If it carries a current i, then the magnetic field on its axis is directly proportional to

An infinitely long straight conductor is bent into the shape as shown in figure. It carries the current I and radius of the circular loop is a, then the magnetic field at the centre of the loop is ______

A long wire bent as shown in fig. carries current I. If the radius of the semicircular portion is a, the magnetic field at centre C is

A conducting circular loop of radius a is connected to two long, straight wires . The straight wires carry a current I as shown in figure . Find the magnetic field B at the centre of the loop.

A current of 2 amp. flows in a long, straight wire of radius 2 mm . The intensity of magnetic field on the axis of the wire is

A long straight solid metal rod of radius 4cm carries a current 2A , uniformly distributed over its circular cross-section. Find the magnetic field induction at a distance 3cm from the axis of the wire.

A uniform disc (of mass M and radius a ) has a hole (of radius b ) drilled through it. The centre of the hole is at a distance c from the centre of the original disc. What is the moment of inertia of the disc about an axis through the centre of the disc and perpendicular to its plane ?

A long wire bent as shown in the figure carries current I=10A . If the radius of the semicircular portion is 1 m, the magnetic induction ("in "muT) at the centre C is