MHT CET202526 Apr 2025Morning ShiftPhysicsCurrent ElectricityActual
The potentiometer wire is 5 m long and potential difference of 4 V is maintained between the ends. The e.m.f. of the cell which balances against a length of 200 cm of the potentiometer wire is
Options
- A0.4 V
- B0.8 V
- C1.2 V
- D1.6 V
Correct answer
D. 1.6 V
Step-by-step solution
Potential gradient is defined as potential difference per unit length: k = V L . Given total length L = 5 m = 500 cm and potential difference V = 4 V , the potential gradient becomes: k = 4 V 500 cm = 0.008 V/cm . The e.m.f. of the cell balancing against length l = 200 cm equals the potential drop across this length: E = k l = 0.008 V/cm 200 cm = 1.6 V . The e.m.f. is therefore 1.6 V , corresponding to option D.