Question

When a current is drawn from battery is 0.5A its terminal voltage is 20v. When current is drawn from it is 2v. Terminal voltage reduced to 16v. Find emf and internal resistance of battery

Answer 1

EMF of the cell = 20V

Terminal voltage V = ?

Internal resistance of the cell = ?

External load resistance = 10 ohm

Load current = 1.8A

Now, Voltage V = IR = 1.8*10= 18V( less than the emf of the cell).

Internal resistance r = E- V/I

20–18/1.8= 1.111 ohm.