Question

An electric iron of resistance 20 Ω draws a current of 5 A. The heat developed in the iron in 30 seconds is ______.

Options

• 15000 J

• 6000 J

• 1500 J

• 3000 J

Answer 1

An electric iron of resistance 20 Ω draws a current of 5 A. The heat developed in the iron in 30 seconds is 15000 J.

Explanation:

I = 5 A, R = 20 Ώ and t = 30 s
H = I²Rt = 5² x 20 x 30 = 25 x 20 x 30 = 15000 J