JEE MainPhysicsCurrent Electricity
A battery of EMF 36 V and internal resistance 2 is connected across terminals A and B. Five resistors are connected between specific nodes: 2 between A and C, 4 between C and B, 4 between A and D, 8 between D and B, and a 10 galvanometer between C and D. The power dissipated in the 8 resistor is:
Options
- A16 W
- B32 W
- C72 W
- D162 W
Correct answer
B. 32 W
Step-by-step solution
The circuit described forms a Wheatstone bridge between terminals A and B, with C and D as the intermediate nodes. The arms of the bridge have resistances: R_ AC = 2 , R_ CB = 4 R_ AD = 4 , R_ DB = 8 Checking the balance condition: R_ AC R_ CB = 2 4 = 1 2 R_ AD R_ DB = 4 8 = 1 2 Since the bridge is balanced, no current flows through the galvanometer between C and D. We can remove the 10 resistor from our calculations. The equivalent resistance of the bridge R_ eq is the parallel combination of the upper branch (A-C