3 Tutor System
Starting just at 265/hour

21. An electric iron of resistance 20Ω takes a current of 5 A. Calculate the heat developed in 30 s.

Heat developed, H = $$I^2 R t$$ = 25 x 20 x 30 = 15,000 J \)
We have, H = $$1.5 x 10^4 J$$