Question

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 ?

Answer 1

The number of turns per unit length is
`n=(500)/(0.5)=1000` turns/ m
The length l=0.5m and radius r=0.01 m Thus, `l//a=50" i.e.,"l gt gt a`.
Hence, we can use the long solenoid formula, namely, Eq. `(B= mu_(0) nI) B=mu_(0)nI`
`=4pi xx 10^(-7)xx10^(3)xx5=6.28xx10^(-3) T`