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When both convection and radiation are included in Newton's law of cooling, the rate of heat loss from a body is (choose the correct statement).

1. directly proportional to the emissivity of the body
2. directly proportional to Stefan's constant
3. directly proportional to the surface area of the body
4. directly proportional to the temperature difference between the body and surroundings

Correct answer: directly proportional to the temperature difference between the body and surroundings

Solution

In Newton's law of cooling regime the heat-loss rate varies directly with the small temperature difference between the body and its surroundings.

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