Question

A voltmeter consists of a 25 Ω coil connected in series with a 575 Ω resistor. The coil takes 10 mA for full-scale deflection. What maximum potential difference can be measured by this voltmeter?

Answer 1

The measured potential difference of the voltmeter is 6V.

Explanation:

For the maximum current, it is given that I = 10 mA. Across the voltmeter, the potential drop will be high.

The circuit’s effective resistance is Reff = 575 + 25 Ω = 600 Ω

The potential difference’s maximum is measured,

V = Reff $\times$ i

= 10 $\times$ 600 $\times$ 10−3 = 6 V

So, the voltmeter’s measured potential difference is 6V.