Question

Two resistors are connected in series across a battery as shown in figure. If a voltmeter of resistance 2000 Ω is used to measure the potential difference across 500 Ω resistor, the reading of the voltmeter will be _____ V.

Fig. Resistors

Answer 1

The correct answer is 8
$R_{eff} = \frac{2000 × 500}{2500} + 600 Ω = 1000 Ω$
⇒ Reading of voltmeter
$= \frac{400}{1000} × 20 = 8$ volts
Therefore , the reading of the voltmeter will be 8 volts.