The p.d. across a lamp is 12 V. How many joules of electrical energy are changed into heat and light when:
(a) a charge of 1 C passes through it?
(b) a charge of 5 C passes through it?
(c) a current of 2 A flows through it for 10 s?
As we know that
Work done = potential difference x charge
a) W= 12 ×1= 12 j
b) W= 12 ×5 = 60 j
c) W = 12 × 2 x 10 = 240 j