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Most Important Selected Qs for JEE AdvancedPhysicsThermal Properties of Matter

A metal block is placed in a room which is at 10^ C for long time. Now it is heated by an electric heater of power 500 W till its temperature becomes 50^ C . Its initial rate of rise of temperature is 2.5^ C / sec . The heater is switched off and now a heater of 100 W is required to maintain the temperature of the block at 50^ C . The heat radiated per second when the block was 30^ C is given as watt. Find the value

Correct answer

5

Step-by-step solution

Given at 50^ C : Newton's Law of cooling Power Loss =100=k(50-10) k= 10 4 = 5 2 At 30^ C P _ Loss = k (30-10)= 5 2 20=50 ~W

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