Question

In the circuit shown below, a voltmeter of
resistance 6 ko is used to measure the voltage
drop across 3 kg resistance, then the reading
of the voltmeter is​

Answer 1

As per the given data the circuit would be -

The voltmeter shows 5V (V1) that means it shows voltage drop across 600 ohm Resistance along with it's internal Resistance, the parallel combination of resistance would be, (let it be R1)

R1=600||1200

R1=400 ohm

Find the current through it ‘I’

V1=I*R1

I=5/400 amps

This is the same current which flows through circuit.

As 5 volts drops across 600 ohm Resistance, remaining 30 volts would be appear across unknown resistor ‘R’

V=I*R

R= V/I

R= (30/5)*400=2400 ohm.

Hope this will help.

Suggestions are welcome.