The magnetic induction at the centre of a solenoid is `B`. If the length of the solenoid is reduced to half and the same wire is would in two layers the new magnetic induction is

The magnetic induction due to toroidal solenoid is independent of

A solenoid have self inductance 2H. If length of the solenoid is double having turn density and area constant then new self inductance is :-

A solenoid have self inductance 2H. If length of the solenoid is double having turn density and area constant then new self inductance is :-

At the mid point along the length of a long solenoid, the magnetic field is equal to x . If the length of the solenoid is doubled and the current is reduced to half, the field at the new mid point will be nearest to