Question

A galvanometer of resistance 50 Ω is converted into a voltmeter of range (0 − 2V) using a resistor of 1.0 kΩ. If it is to be converted into a voltmeter of range (0 − 10 V), the resistance required will be ______.

Options

• 4.8 kΩ

• 5.0 kΩ

• 5.2 kΩ

• 5.4 kΩ

Answer 1

A galvanometer of resistance 50 Ω is converted into a voltmeter of range (0 − 2V) using a resistor of 1.0 kΩ. If it is to be converted into a voltmeter of range (0 − 10 V), the resistance required will be 5.2 kΩ.

Explanation:

V = I_g(G + R) 

I-Case:

2 = I_g(50 + 1000)

`I_g = 2/1050 A`

II-Case:

10 = I_g(50 + R)

`10 = 2/1050 (50 + R)`

`R = (10(1050))/2 -50`

R = 5.2 kΩ