Question

An electric iron of resistance 20 ohm take a current of 5 amperes. Calculate the heat developed in 30 seconds

Answer 1

given:
R=20ohm
I=5A
t=30seconds
H=?

therefore,
H =I^2Rt
H=(5)^2(20)(30)
= (25)(20)(30)
= 25(600)
= 15000

therefore heat will produce 15000

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