GATE 2022 BM – Question 35
In the shown 10 V resistive circuit, the 3 Ω resistor dissipates 12 W. Find the unknown resistance R in ohms.
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Correct answer: 6 to 6
Explanation
The voltage across the three-ohm resistor is √(PR)=√36=6 V. The entire right parallel group has this voltage, leaving four volts across the left group, whose equivalent resistance is 2||1=2/3 Ω. Total current is 4/(2/3)=6 A. Right-group currents through three and two ohms are two and three amperes, leaving one ampere through R. Therefore R=6/1=6 Ω.