Question

- State Joule's law of heating and give its mathematical form,
An electric iron takes a current of 5 A and develops
1.5 x 104 J of heat energy in 30 s. Calculate the resistance
of the electric iron.​

Answer 1

Answer:

joule law of heating is H = I^2 RT where

I = Current

R = Resistence

T = Time

H = Heat

I = 5A

R =?

T = 30 s

H = 1•5 x10^4

H = I^2 RT

1•5 x10^4= 25*R*30

15000 = 750R

R = 15000/750

= 20 ohm