A storage battery of emf 28.0 ~V and internal resistance 0.5 is being charged by a 140 ~V dc supply using a series resistor of 27.5 . The terminal voltage of the battery during charging is

Step-by-step solution

The circuit consists of a DC supply of V_ s = 140 V , a series resistor R = 27.5 , and a battery being charged with emf E = 28.0 V and internal resistance r = 0.5 . The total resistance in the circuit is R_ total = R + r = 27.5 + 0.5 = 28.0 . The charging current I is given by the formula I = V_ s - E R_ total . Substituting the values, I = 140 V - 28.0 V 28.0 = 112 V 28.0 = 4 A . The terminal voltage V of the battery during charging is given by V = E + Ir . Substituting the values, V = 28.0 V + (4 A 0.5 ) = 28.0 V