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A electric kettle ( rated accurately at ...

A electric kettle ( rated accurately at `2.5 kW`) is used to heat `3 kg` of water from `15^(@)C` to boiling point . It takes `9.5 min`. Then the amount of heat that has been lost is

A

`3.5 xx 10^(5) J`

B

`7 xx 10^(8) J`

C

`3.5 xx 10^(4) J`

D

`7 xx 10^(8) J`

Text Solution

Verified by Experts

The correct Answer is:
A
Energy consumed in `9.5 min ` is
`2.5 xx 1000 xx 9.5 xx 60 J = 1425000 J`
Heat usefully consumed is
` 3 xx 4.2 xx 1000 xx (100 - 15 ) J = 1071000 J`
Loss `= 3.54 xx 10^(5) J`
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