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A water heater of power 2000 W is used to heat water. The specific heat capacity of water is 4200 J kg - 1 K - 1 . The efficiency of heater is 70 % . Time required to heat 2 kg of water from 10 ° C to 60 ° C is _____ s . (Assume that the specific heat capacity of water remains constant over the temperature range of the water).

Correct answer

0

Step-by-step solution

Heat provided to water will be responsible for increase in temperature. Therefore, we can write η × P × t = M × s × Δ T Now, η = 70 100 = 0 . 7 and energy = power × time . Therefore, t = 2 × 4200 × 60 ° - 10 ° 0 . 7 × 2000   s = 300   s

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