Moving Charges ...

If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be

The magnetic induction at a point P which is at a distance 4 cm from a long current carrying wire is 10^–8 tesla. The field of induction at a distance 12 cm from the same current would be

A wire of length l is bent into a circular loop of radius R and carries a current I. The magnetic field at the centre of the loop is B. The same wire is now bent into a double loop of equal radii. If both loops carry the same current I and it is in the same direction, the magnetic field at the centre of the double loop will be

Two concentric circular coils of ten turns each are situated in the same plane. Their radii are 20 and 40 cm and they carry respectively 0.2 and 0.3 ampere current in opposite direction. The magnetic field in weber/m² at the centre is

If the strength of the magnetic field produced 10 cm away from a infinitely long straight conductor is 10^–5 weber/m², the value of the current flowing in the conductor will be

A long straight wire of radius \'a\' carries a steady current i. The current is uniformly distributed across its cross section. The ratio of the magnetic field at a/2 and 2a is

Magnetic field intensity at the centre of coil of 50 turns, radius 0.5 m and carrying a current of 2 A is

The magnetic field at a distance r from a long wire carrying current i is 0.4 tesla. The magnetic field at a distance 2r is

A long solenoid of length L has a mean diameter D. It has n layers of windings of N turns each. If it carries a current \'i\' the magnetic field at its centre will be

A closely wound flat circular coil of 25 turns of wire has diameter of 10 cm and carries a current of 4 ampere. Determine the flux density at the centre of a coil