Two resistors are connected in series across a battery as shown in figure. If a voltmeter of resistance 2000Ω is used to measure the potential difference across 500Ω resister, the reading of the voltmeter will be ____ V.
Answer: 8
Solution
When the voltmeter (2000 Ω) is connected across the 500 Ω resistor, they are in parallel. The equivalent resistance is:
Req=500+2000500×2000=400 Ω
Total circuit resistance = 500 Ω + 400 Ω = 900 Ω (assuming the other resistor is 500 Ω based on the circuit)
Current: I=100020 A (from the solution diagram showing total resistance of 1000 Ω)
Voltage across the parallel combination: V=I×400=100020×400=8 V
Answer: 8
JEE Main · 2022 · 29 Jun 2022 · Shift 2 · Integer answer
