Question

A voltmeter of resistance 400Ω is used to measure the potential difference across the 100Ω resistor in the circuit shown in figure (32-E24). (a) What will be the reading of the voltmeter ? (b) What was the potential difference across 100Ω before the voltmeter was connected ?

Answer 1

Voltage measured by the voltmeter =0.24x100/24V

b) If voltmeter is not connected

Reff = (200 + 100) = 300Ω

i =84/300 = 0.28 A

Voltage across 100Ω = (0.28 x 100) = 28 V.