Question

In a current-carrying long solenoid, the magnetic field produced does not depend upon

Answer 1

1. A solenoid is a coil of a long, insulated copper wire closely wound on a cylinder.
2. The magnetic field of a solenoid on its axis is given by the formulae, $B={\mu }_{0}nI$, where ${\mu }_0$ is the permittivity of free space, n = is the number of turns in unit length and I is the current flowing in the solenoid.
3. So it is clear that the magnetic field produced in a solenoid does not depend on the radius of the solenoid.

Hence, in a current-carrying long solenoid, the magnetic field produced does not depend upon the radius of the solenoid.