Question

Three 2 V cells are connected in series and used as a battery in a circuit. 

How many joules of electrical energy does 1 C gain on passing through (i) one cell (ii) all three cells?

Answer 1

(i) For one cell:
V = 2 V
Q = 1 C
And also:
Electrical energy gained = Work done
So using the relation, V = W/Q or W = V x Q
= 2 x 1 = 2 J
(ii) For three cells:
V = 6 V
Q = 1 C
So, W = V x Q = 6 x 1 = 6 J
So 2 joules and 6 joules of electrical energy is gained for the above two cases (i) one cell and (ii) all three cells, respectively.