A solenoid of length 0.5 m has a radius of 1 cm and is made up of 500 turns. It carries a current of 5 A. What is the magnitude of the magnetic field inside the solenoid ?

Explanation

The number of turns per unit length is,
`n = (500)/(0.5) = 1000` turns/m
The length l = 0.5 m and radius r = 0.01 m. Thus, l/a = 50 i.e., l > > a. Hence, we can use the long solenoid formula, namely, Eq.
`B = mu_0 n I`
` = 4 pi xx 10^(-7) xx 10^3 xx 5`
`= 6.28 xx 10^(-3) T`