Which among the following is/are example/s of sink ?

Which among the following is/are example/s of sink ?

a. River
b. Sea
c. Atmosphere
d. all of the above

Correct Answer : d. all of the above

Explanation :

Sink is the thermal energy reservoir to which heat is rejected from the system which works on heat engine cycle. Heat engine utilizes the heat energy coming from the source and produces work output. But all the heat energy from the source is not converted into work and some amount of heat energy is rejected to the thermal energy reservoir which is called as sink. The above examples river, sea and atmosphere are huge enough that if some heat is rejected to them then there will not be any considerable change in their temperatures. Therefore they are the examples of sink.