Question

A voltmeter has a range of 0 - 20 V and a resistance of 500 Q. Explain how can be used to measure voltages from 0 - 200 volt?

Answer 1

Given: V_g = 20 V, G = 500Ω, V = 200 V

`V_g=I_g.G`

`I_g=V_g/G`

`=20/500`

`=0.04 A`

Now,

`R=(V-V_g)/I_g`

`=(200-20)/0.04`

`=180/0.04`

`=4500Ω`