JEE MainPhysicsCurrent Electricity
A DC circuit has two terminals A and B. A 4 resistor is connected directly between A and B. From terminal A, a 1 resistor connects to a node C. An unknown resistor R connects node C to terminal B. From node C, a 6 resistor connects to a node D. A 10 resistor connects node D to terminal B. Finally, an ideal conducting wire also connects node D directly to terminal B. If the equivalent resistance across terminals A and
Correct answer
6
Step-by-step solution
The ideal conducting wire connects node D directly to terminal B, which means node D is at the same potential as terminal B. This short-circuits the 10 resistor, so no current flows through it. The 6 resistor, originally connected between C and D, is now effectively connected between C and B. This places it in parallel with the unknown resistor R , which is also connected between C and B. The equivalent resistance of this parallel combination is R_ CB = 6R 6+R . This combination is in series with the 1 resistor (co