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

The magnetic field intensity $(H)$ at the centre of a long solenoid having '$n$' turns per unit length and carrying a current $I$, when no material is kept in it is ($\mu_0$ = permeability of free space)

The magnetic induction along the axis of a toroidal solenoid is independent of

The magnetic induction due to an ideal solenoid is independent of

$A$ solenoid of $1000$ turns is wound uniformly on a glass tube $4 \text{ m}$ long and $0.3 \text{ m}$ in diameter. The magnetic intensity at the centre of the solenoid when a current of $4 \text{ A}$ flows through it is

$A$ solenoid $2 \,m$ long and $4 \,cm$ in diameter has $4$ layers of windings of $1000$ turns each and carries a current of $5 \,A$. What is the magnetic field at its centre along the axis? $\left[\mu_0=4 \pi \times 10^{-7} \,Wb / Am\right]$