(i) A storage battery of emf `8V`, internal resistance `1 Omega` is being charged by a `120 V` d.c. source using a `15 Omega` resistor in series in the circuit. Calculate the current in the circuit (ii) terminal voltage across the battery during charging and (ii) chemical energy stored in the battery in `5` minutes.

Answer

`(i)7A,(ii)15V,(ii)16800 J`

Explanation

Effective emf of the circuit `epsilon = 120 - 8 = 112V`
Total resistance of circuit `R = 1 + 15 = 10 Omega` ltbr gt (i) current `I = (epsilon)/(R ) = (112)/(10) = 7A`
(ii) Terminal voltage during charging
`V = epsilon + Ir = 8 + 7 xx xx 1 = 15 V`
(iii) Chemical energy stored in the battery in `5` minutes ` = epsilon It = 8 xx 7 xx (5 xx 60)= 16800 J`