Q 12-04-234JEE MainJEE Main 2017 (2 Apr)Easy
When a current of $5$ mA is passed through a galvanometer having a coil of resistance $15\ \Omega$, it shows full-scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range $0$–$10$ V is:
Answer: (B) $1.985\times10^3\ \Omega$
At full scale, $I_g(G + R) = V$:
$$R = \frac{V}{I_g} - G = \frac{10}{5\times10^{-3}} - 15 = 2000 - 15 = 1985\ \Omega = 1.985\times10^3\ \Omega$$
Solution by Sreeraj P, M.Sc Physics