The correct curve between the magnetic induction (B) along the axis of a along solenoid due to current flow i in it and distance x from one end is -

Magnetic field B along the axis of a long solenoid is given by

The magnetic field along the axis of an air cored solenoid is B. The magnetic field energy density is

Magnetic field at a distance x along the axis of a short bar magnet is

A charged particle of charge q moving with the velocity v, enters along the axis of a solenoid carrying a current. If B is the magnetic induction along the axis of the solenoid then the force acting on the charged particle will be

A current i ampere flows along the inner conductor of a coaxial cable and returns along the outer conductor fo the cable, then the magnetic induction at any point outside the conductor at a distance r metre from the axis is

A current i ampere flows along the inner conductor of a coaxial cable and returns along the outer conductor fo the cable, then the magnetic induction at any point outside the conductor at a distance r metre from the axis is