NEET2014PhysicsCurrent ElectricityActual
A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0   V and a negligible internal resistance. The potentiometer wire itself is 4   m long. When the resistance, R , connected across the given cell, has values of. i infinity i i   9.5   Ω The 'balancing lengths, on the potentiome
Options
- A0.25 Ω
- B9.5   Ω
- C0.5 Ω
- D0.75 Ω
Correct answer
C. 0.5 Ω
Step-by-step solution
Here, we have to calculate the internal resistence of the unknown cell. So, we have to use the following formulae: Internal resistance of the unknown cell is r = l 1 l 2 - 1 R = 3 2.85 - 1 9.5 Ω = 0.5 Ω Hence the internal resistance will be 0.5 Ohm