Moving Charges ...

A steady current flows in a long wire. It is bent into a circular loop of one turn and the magnetic field at the centre of the coil is B. If the same wire is bent into a circular loop of n turns, the magnetic field at the centre of the coil is

A wire carrying current i is shaped as shown. Section AB is a quarter circle of radius r. The magnetic field is directed

A steady current I flows along an infinitely long hollow cylindrical conductor of radius R. This cylinder is placed coaxially inside an infinite solenoid of radius 2R. The solenoid has n turns per unit length and carries a steady current I. Consider a point P at a distance r from the common axis. The correct statement (s) is (are)

A current I flow in an infinitely long wire cross-section in the form of a semi-circular ring of radius R. The magnitude of the magnetic induction along its axis is

A current of i ampere flows in a circular area of wire which subtends an angle of (3π/ 2) radian at its centre, whose radius is R. The magnetic induction B at the centre is

The magnetic field on the axis of a long solenoid having n turns per unit length and carrying a current i is

A current i is passing through a straight conductor of infinite length. The magnetic field at a point situated at a distance R from the conductor is

A current i is flowing through the loop. The direction of the current and the shape of the loop are as shown in the figure.

PQ and RS are long parallel conductors separated by certain distance. M is the mid-point between them (see the figure). The net magnetic field at M is B. Now, the current 2 A is switched off. The field at M now becomes

Magnetic field at the centre of a circular coil of radius R due to i flowing through it is B. The magnetic field at a point along the axis at distance R from the centre is