An electric iron contumea energy at a rate of 840W whe.n heating la at the maximum and 360W, when the heating la at the minimum. The voltage at which it is running is 220V. What are the cunent and resistance values in each case ?

Explanation

`P_(1) =840 W ` V= 220 V
Current drawn `I_(1) =(P_(1))/(V)`
`=(840)/(220)= (42)/(11) = 3.8 A `
`P_(2) = 360 W V= 220 V `
Current drawn `I_(2) = (P_(2))/(V)= (360)/(220) = 1.6 A `
By Ohm .s Law
`V= I_(1) R_(1)`
`R_(1) =(V)/(I_(1)) = (220)/((42)/(11))=(220xx11)/(42)= (1210)/(21)Omega = 57.5 Omega`
`V= I_(2) R_(2)`
`R_(2) =(V)/(I_(2) = (220)/((18)/(11))=220xx(11)/(18)=134.4Omega`