69) The unit of Stefan Boltzmann constant is

Answer is:

watt/cm2 °K4

Explanation:

According to Stefan's law, the total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature. Stefan Boltzmann law is applicable for heat transfer by radiation. The unit of Stefan-Boltzman is Watt/m²K⁴.

Heat transfer MCQ with Answers

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70) In free con-vection heat transfer, Nusselt number is function of

Answer is:

Grashoff no. and Prandtl no.

71) Stefan Boltzmann law is applicable for heat transfer by

Answer is:

radiation

Explanation:

Stefan Boltzmann law is applicable for heat transfer by radiation. According to Stefan's law, the total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature.