Question

A bulb marked 12 V, 24 W operated on a 12 volt battery for 20 minutes. Calculate:
(i) the current flowing through it, and
(ii) the energy consumed

Answer 1

Given,
Power, p = 24 w
Voltage, v = 12 v
Current, I = ?
As power, p = VI

(i) I = `24/12` = 2 A

(ii) Energy, E = P × t
                 E = 24 × 20 × 60 sec
                 E = 28, 800 J