Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Heat Transfer
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Heat Transfer
Newton's law of cooling represents a special case of
Newton's law of cooling represents a special case of
Options
- APlanck's law
- BKirchhoff's law
- CStefan's law
- DWien's displacement law
Correct answer
C. Stefan's law
Step-by-step solution
According to Stefan's law, the net rate of heat loss by radiation from a body at temperature in surroundings at temperature is given by .
Let , where the temperature difference is very small compared to .
Substituting this into Stefan's law:
P = e \sigma A T_0^4 \left[ \left(1 +\dfrac{\Delta T}{T_0}\right)^4 - 1\right]P \approx e \sigma A T_0^4 \left[1 + 4\dfrac{\Delta T}{T_0} - 1\right]P \approx 4 e \sigma A T_0^3 \Delta T4 e \sigma A T_0^3P \propto \Delta T.
This is Newton's law of cooling, which states that the rate of heat loss is directly proportional to the temperature difference between the body and its surroundings. Thus, Newton's law of cooling is a special case of Stefan's law.
Let , where the temperature difference is very small compared to .
Substituting this into Stefan's law:
P = e \sigma A T_0^4 \left[ \left(1 +\dfrac{\Delta T}{T_0}\right)^4 - 1\right]P \approx e \sigma A T_0^4 \left[1 + 4\dfrac{\Delta T}{T_0} - 1\right]P \approx 4 e \sigma A T_0^3 \Delta T4 e \sigma A T_0^3P \propto \Delta T.
This is Newton's law of cooling, which states that the rate of heat loss is directly proportional to the temperature difference between the body and its surroundings. Thus, Newton's law of cooling is a special case of Stefan's law.