2nd Law of Thermodynamics

What is second law of thermodynamics?

• change in Internal energy equal to difference of heat supplied and work done by the system

• if two thermodynamic systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other

• Energy neither create nor destroy but it is only can convert to another form

• Although nett heat supplied in a cycle is equal to nett work done, gross heat supply must be always greater than work done

Heat sink is a ...............

• Reservoir that rejects work

• Reservoir that supplies heat

• Reservoir that absorbs heat

• Reservoir that produces work

Heat source is ..............

• Reservoir that rejects work

• Reservoir that absorbs heat

• Reservoir that supplies heat

• Reservoir that produce work

Choose figure that tells about a heat engine

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Choose figure that tells about a reversed heat engine

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What is a heat engine?

• device that make heat flow from low temperature to high temperature

• device that use heat to produce work

• device that make heat flow from cold to hot

• device that use work to produce heat

What is reversed heat engine?

• Device that make heat flow from hot to cold

• Device that make heat flow from cold to hot

• Device that use work to supplies energy

• device that use heat to produce workk

Choose the application of heat engine

• power plant

• locomotive engine

• refrigerator

• all above

Choose application of reversed heat engine

• refrigerator

• air conditioning

• heat pump

• all above

what is the difference between heat pump and air conditioning?

• Desire output for heat pump is a Q_L and desire output for air conditioning is Q_H

• Desire output for heat pump is a Q_H and desire output for air conditioning is Q_L

• Desire input for heat pump is a Q_H and desire output for air conditioning is Q_L

• Desire input for heat pump is a Q_H and desire output for air conditioning is Q_L