Question

An electric iron of resistance 20 ohm takes a current of 5a. calculate the heat developed in 30 sec

Answer 1

h=I^2 rt
(5)^2 ×20 ×30 = 15000 J

Answer 2

Given :-

R = 20 Ω

I = 5 A

t = 30 s

H = I^2Rt

= (5)^2×20×30

= 15000 J

= 1.5 × 10^4 J