NSEJS - P#2

As the magnetic field inside a solenoid is $B=\mu n I$ , where $\mu=\mu_r\cdot\mu_0$ , $\ \mu_0$ is the vacuum permeabilty ( $\mu_0=4\pi\times10^{-7} T\cdot m/A$ ), $n$ is the number of turns per unit lenght of the solenoid and $I$ is the intensity of the electric current circulating through the wire.

Plugging $\mu_r=4000; n=4000; I=5A$ into the equation, we get $B=4000\times 4\pi*10^{-7} T\cdot m/ A \times 4000 m^{-1} \times 5A = 32\pi \ T \approx 100.531 T$