Heat questions | form five Physics

Define thermal convection.

Prove that at a very small temperature difference, Δ​T = ​ T_b - ​ T_s Newton’s law of cooling
obeys Stefan’s law, whereby ​ T_b ​ is the temperature of the body and ​ T_s is the temperature of the surrounding.

What is meant by temperature of inversion?.

A thermometer was wrongly calibrated as it reads the melting point of ice as -10°C and
reading a temperature of 60°C in place of 50°C. What would be the temperature of boiling
point of water on this scale?

Name the temperature of a thermocouple at which the thermo,

1. e.m.f changes its sign.
2. electrict power becomes zero.

A person sitting on a bench on a calm hot summer day is aware of a cool breeze blowing from the sea. Briefly explain why there is a natural convection?

A Nichrome-constantan thermocouple gives about 70µV for each 1°C difference in temperature between the junction. If 100 such thermocouples are made into a thermopile, what voltage is produced when the junctions are at 20°C and 240°C?

A black body of temperature is places in a blackened enclosure maintained at a temperature of 10°C. When its temperature rises to 30°C the net rate of loss of energy from the body was found to be 10watts. Find the power generated by the body at 50°C of the energy exchange takes place solely by the process of forced convection.

Compare the law governing the conduction of heat and electricity pointing out the corresponding quantities in each case.

Write down three laws governing the black body radiation.