Question

Find the magnetic field produced by the solenoid if the number of loops is 400

       and current passing through it is 5A. (Length of the solenoid is 40cm).

Answer 1

We know that

$B=\mu_0ni$

$n=\frac{N}{l}=\frac{400}{0.40}=1000$

N=400

L=0.40m

i=5A

Put value in equation

$$B=4\times3.14\times10^{-7}\times1000\times5=6.28\times10^{-3}T$$

$B=6.28\times10^{-3}T$