Question

A current of $4A$ flows through $5$ turn coil of a tangent galvanometer having a diameter of $30cm$. If the horizontal component of Earth's magnetic induction is $4\times {10}^{-5}T$, find the deflection produced in the coil.
[Given ${\mu }_0=4\pi \times {10}^{-7}H{m}^{-1}]$

Answer 1

$n=5;I=4A;d=3\times {10}^{-1}m$;
$B_h=4\times {10}^{-5}T$;
$a=1.5\times {10}^{-1}m;\theta =?$
$I=\frac{2a{B}_h}{{\mu }_{0}n}\tan \theta$
$\therefore \tan \theta =\frac{{\mu }_{0}nI}{2a{B}_h}=\frac{4\pi \times {10}^{-7}\times 5\times 4}{2\times 1.5\times {10}^{-1}\times 4\times {10}^{-5}}$
$\tan \theta =2.093$
$\therefore \theta ={64}^{\circ }28$.