A) 1050 W
B) 2100 W
C) 1500 W
D) 3000 W
Correct Answer: A
Solution :
Power is the amount of work done or energy (Q ) transferred per unit of time (t). \[\therefore \] \[P=\frac{H}{t}\] \[H=mc\Delta \theta \] where m is mass, c the specific heat and\[\Delta \theta \]the temperature difference. \[\therefore \] \[P=\frac{mc\Delta \theta }{t}\] \[\Delta \theta ={{(35-20)}^{o}}C={{15}^{o}}C\] \[C=1000,\] \[4.2\text{ }J=1\text{ }cal\] \[t=1\text{ }\min =60\text{ }s\] \[\therefore \]\[P=\frac{1\times 1000\times 15\times 4.2}{60}J/s=1050W\]You need to login to perform this action.
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