An electric iron consumes energy at a rate of 840W when heating is at the maximum rate and 360W when the heating is at the minimum. The voltage is 220V. What are the current and the resistance in each case?

An electric iron consumes energy at a rate of 840W when heating is at

1.	An electric iron consumes energy at a rate of 840W when heating is at the maximum rate and 360W when the heating is at the minimum. The voltage is 220V. What are the current and the resistance in each case?
Answer» Solution :(a) When heating is at maximum rate, the POWER rating P=840 W and supply voltage V=220V `therefore` Current flowing `I=P/V=(840 W)/(220 V)=3.82 A` and resistance of electric iron `R=V/I=(220V)/(3.82A)=57.6 OMEGA` (b) When heating is at minimum rate, the power rating P=360W `therefore` Current flowing `I=P/V=(360 W)/(220 V)=1.64A` and resistance of electric iron `R=V/I=(220V)/(1.64A)=134.2 Omega`