Question

An electric iron of resistance 30 ohms takes current of 15 amphear calculate the heat produced in 40 sec

Answer 1

$h = i^{2} rt$
r=30 ohm
i=15 A
t=40 sec
Now,
H=15×15×30×40
H=270000 J
So the heat produced is 270 KJ

Answer 2

H = I^2rt 

r=30 ohm

i=15 A

t=40 second

H=15×15×30×40

H=270000 J

therefore , the heat produced is 270000J