Question

A millimeter of range $10mA$ has a coil of resistance $1\Omega$. To use it as voltmeter of range $10volt$, the resistance that must be connected in series with it will be

• A. $999\Omega$
• B. $99\Omega$
• C. $1000\Omega$
• D. None of these

Answer 1

The correct option is A $999\Omega$

Given Data

Millimeter resistance = $1\Omega$

Current on Millimeter = $10mA$

Voltmeter = $10V$

$R=\frac{V}{i_g}-G=\frac{10}{10\times {10}^{-3}}-1=999\Omega$