Question

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

Answer 1

Answer:

8 A is the correct answer

Answer 2

Given

An electric iron of resistance 20 Ω takes a current of 5 A

Find out

We have to calculate the heat developed in 30 s.

Solution

The amount of heat (H) produced is given by the joule’s law of heating as

H= Vlt

Where,

Current (I) = 5 A

Time (t) = 30 s

Voltage (V) = Current x Resistance

V = 5 x 20

V = 100V

H= 100 x 5 x 30

H = 1.5 x 104 J.

Therefore, the amount of heat developed in the electric iron is 1.5 x 104 J.