Question

In a tangent galvanometer a deflection of ${30}^o$ is obtained with a certain current flowing through the coil. If the current is tripled, the deflection obtained will be

• A. ${45}^o$
• B. ${60}^o$
• C. ${90}^o$
• D. ${30}^o$

Answer 1

The correct option is B ${60}^o$

$\frac{\tan {\theta }_1}{\tan {\theta }_2}=\frac{i_1}{i_2}$ $\therefore (B_4\tan \theta =\frac{{\mu }_{0}i}{2r})$
$\frac{\tan {30}^o}{\tan {\theta }_2}=\frac{1}{3}$
$\tan {\theta }_2=\sqrt{3}$
${\theta }_2={60}^0$