Question

A solenoid of length 0.6 m has a radius of 2 cm and is made up of 600 turns If it carries a current of 4 A, then the magnitude of the magnetic field inside the solenoid is
A. `6.024xx10^(-3)T`
B. `8.024xx10^(-3)T`
C. `5.024xx10^(-3)T`
D. `7.024xx10^(-3)T`

Answer 1

Correct Answer - C
Here, `n=(600)/(0.6)="1000 turns/m, I = 4 A"`
`"l = 0.6 m, r = 0.02 m "because (l)/(r)=30` i.e., `l gt gt r`
Hence, we can use long solenoid formula, then
`therefore " "B=mu_(0)nI=4pi xx10^(-7)xx10^(3)xx4=50.24 xx10^(-4)`
`=5.024 xx10^(-3)T`