An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature 20^@C ? The temperature of boiling water is 100^@ C.

An electric kettle takes 4 A current at 220 V. How much time will it t

1.	An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature 20^@C ? The temperature of boiling water is 100^@ C.
Answer» 6.3 min 8.4 min 12.6 min 4.2 min Solution :Heat required to boil water of 1 kg from `20^@C` to `100^@C` `Q=ms DeltaQ=(1xx4200xx80)` J Power of kettle (P)=VI=(220 X 4) W `therefore` Time TAKEN= `Q/P` `=(1xx4200xx80)/(220xx4)` =381.81 s =6.36 min