MHT CET202616 April 2026Morning ShiftPhysicsCurrent ElectricityActual
A potentiometer wire is 4m long and potential difference of 3V is maintained between the ends. The e.m.f. of the cell which balances against a length of 100 cm of the potentiometer wire is
Options
- A0.75 V
- B0.5 V
- C0.25 V
- D1.5 V
Correct answer
A. 0.75 V
Step-by-step solution
The potential gradient k of the potentiometer wire is given by the potential difference per unit length. k = V L = 3 4 V/m The balancing length for the cell is l = 100 cm = 1 m. The e.m.f. of the cell E is given by the product of the potential gradient and the balancing length. E = k l = 3 4 1 = 0.75 V Answer: 0.75 V