Question

An electric iron of resistance 20ohm draws a current of 5A. Calculate the heat produced in 30seconds.

Answer 1

H= I^2 x R x t
H = 25 x 20 x 30
H = 15, 000 joule

Answer 2

given that,
R = 20ohm
I = 5A
t = 30secs
now,
as we know that,
H = I²RT
So,
H= 25 × 20 × 30
H = 25 × 600
H = 1500 J