The radiator of a steam heating system has a volume of 20 L and is filled with superheated water vapor at 200 kPa and 150oC. At this moment, both the inlet and the exit valves to the radiator are closed. After a while, the temperature of the steam drops to 40oC as a result of heat transfer to the room air. Determine the entropy change of the steam during this process

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.