Question

The tangent galvanometers having coils of the same radius are connected in series. A current flowing in them produces deflections of $60^{o}$ and $45^{o}$ respectively. The ratio of the number of turns in the coil is:

• A. $\left(\frac{4}{3}\right)$
• B. $\frac{\left(\sqrt{3} + 1\right)}{1}$
• C. $\left(\frac{\sqrt{3} + 1}{\sqrt{3} - 1}\right)$
• D. $\frac{\sqrt{3}}{1}$

Answer 1

Answer: (D)

In series current is same. In tangent galvanometer
$B=B_{H}tan \theta \Rightarrow \frac{\mu _{0} n i}{2 R}=B_{H} \, tan\theta $
$\because i=$ same
$\therefore n \, \propto tan \theta \Rightarrow \frac{n_{1}}{n_{2}}=\frac{tan ⁡ 60^{o}}{tan ⁡ 45^{o}}=\frac{\sqrt{3}}{1}$