A secondary cell after long use has an emf of 1.9 V and a large internal resistance of 380Ω. What maximum current can be drawn from the cell? Could the cell drive the starting motor of a car?

Question

Philoid · Accepted Answer

Emf of secondary cell E = 1.9Volt

Internal resistance of cell r = 380 Ω

⇒ I = 1.9V/380Ω

⇒ I = 0.005Ampere

Hence maximum current drawn from cell is 0.005Ampere and since a large current is required to start the motor of a car and hence cell cannot be used to start the motor.