- Heat Transfer - Section 1
- Heat Transfer - Section 2
- Heat Transfer - Section 3
- Heat Transfer - Section 4
- Heat Transfer - Section 5
- Heat Transfer - Section 6
- Heat Transfer - Section 7
- Heat Transfer - Section 8
- Heat Transfer - Section 9
- Heat Transfer - Section 10
- Heat Transfer - Section 11


Heat Transfer - Engineering
Q1: A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions ? Assume that the conductive heat transfer co-efficient is infinitely large.A 5 minutes
B 10 minutes
C 20 minutes
D 40 minutes
ANS:A - 5 minutes To solve this problem, we can use Newton's Law of Cooling, which states that the rate of change of temperature of an object is proportional to the difference between its temperature and the surrounding temperature. The equation for Newton's Law of Cooling is: dtdT=−k⋅(T−Tambient) where:
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