Question

A galvanometer of resistance $10\, \Omega$ gives full-scale deflection when $1\, mA$ current passes through it. The resistance required to convert it into a voltmeter reading upto $2.5\, V$ is

• A. $24.9\,\Omega$
• B. $249\,\Omega$
• C. $2490\,\Omega$
• D. $24900\,\Omega$

Answer 1

Answer: (C)

$2490\,\Omega$

Answer 2

Required series resistance
$R =\frac{V}{I_{g}}-G$
$=\frac{2.5}{1 \times 10^{-3}}-10$
$=2490\, \Omega$