An electric iron is connected to the mains power supply of 220V. When the electric iron is adjusted at ‘minimum heating’ it consumes a power of 360W but at ‘maximum heating’ it takes a power of 840W. Calculate the current and resistance in each case.

Question

Accepted Answer

Given,
V = 220V
Pmin = 360W Pmax = 840 W
When the heating is minimum, Pmin = VI
360 = I220
I = 1.63amp R = V/I
R = 200/1.63
R = 134.96 ohms
When the heating is maximum, Pmax = VI
840 = 220I
I = 3.81amp R = V/I
R = 220/3.81
R = 57.74 ohms

V = 220V

360 = I220

R = 200/1.63

840 = 220I

R = 220/3.81

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