Question

A solenoid of length $50cm$ with $600turns$ is connected to a cell and current through the solenoid is $\frac{20}{\pi }A$. Assuming solenoid to be ideal, magnetic field inside the solenoid (in central region) is found to be $N\times {10}^{-4}\text{T}$ then the value of $N$ is

Answer 1

$B={\mu }_{o}ni$
$n=\frac{N}{l}=\frac{600}{0.5}=1200$
$i=\frac{20}{\pi }$
$B=4\pi \times {10}^{-7}\times 1200\times \frac{20}{\pi }$
$=96\times {10}^{-4}T$