Question

A galvanometer of $50$ ohm resistance has $25$ divisions. $A$ current of $4\times 10^{-4}$ ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of $25$ volts, it should be connected with a resistance of

• A. $2500 \, \Omega$ as a shunt
• B. $2450 \, \Omega$ as a shunt
• C. $2550 \, \Omega$ in a series
• D. $2450 \, \Omega$ in a series

Answer 1

Answer: (D)

$2450 \, \Omega$ in a series

Answer 2

According to question $25 = I(R + R_g)$
$= (4 \times 10^{-4} \times 25)(R + 50)$
$\Rightarrow R = 2450\,\Omega$