Question

7. An electric iron of resistance 20 ohm takes a current of 5 A. Calculate heat produced in 30sec. If it is rated as 2000W, how much will it draw from a source of 220V ?

Answer 1

H= I^2Rt

Using this formula, H= 25*20*30 =15000

and P=VI

using this 2000 W= 220 *I

I = 2000/220 =9.09 Ampere

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

P = VI

I = 2000/220

= 9.09 A