Moving Charges ...

A long solenoid is formed by winding 20 turns/cm. The current necessary to produce a magnetic field of 20 millitesla inside the solenoid will be approximately

A battery is connected between two points A and B on the circumference of a uniform conducting ring of radius r and resistance R. One of the arcs AB of the ring subtends an angle θ at the centre. The value of the magnetic induction at the centre due to the current in the ring is

A current of 1 ampere is passed through a straight wire of length 2.0 metres. The magnetic field at a point in air at a distance of 3 metres from either end of wire and lying on the axis of wire will be

A long copper tube of inner radius R carries a current i. The magnetic field B inside the tube is

A straight wire of length (π²) metre is carrying a current of 2A and the magnetic field due to it is measured at a point distant 1 cm from it. If the wire is to be bent into a circle and is to carry the same current as before, the ratio of the magnetic field at its centre to that obtained in the first case would be

Due to 10 ampere of current flowing in a circular coil of 10cm radius, the magnetic field produced at its centre is 3.14 × 10^–3 weber/m². The number of turns in the coil will be

There are 50 turns of a wire in every cm length of a long solenoid. If 4 ampere current is flowing in the solenoid, the approximate value of magnetic field along its axis at an internal point and at one end will be respectively

A steady electric current is flowing through a cylindrical conductor

A vertical wire kept in Z-X plane carries a current from Q to P (see figure). The magnetic field due to current will have the direction at the origin O along

In a hydrogen atom, an electron moves in a circular orbit of radius 5.2 × 10^–11 m and produces a magnetic induction of 12.56 T at its nucleus. The current produced by the motion of the electron will be (Given μ₀ = 4π × 10^–7 Wb/A–m)