Question

A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V.
calculate:
(i) the resistance of the wire and
(ii) the heat energy produced in 1 minute.

Answer 1

Given,

   Current, I = 0.2 A
Potential difference, v = 15 v
Time, t = 60 sec
As v = IR

(a) R = `15/0.2` = 75 Ω 

(b) Heat energy, H = ` I^2` Rt`

                           H = `(0.2)^2 xx75xx60`
Or                       H = 180 J