Which of the following contributes to the efficiency of Rankine cycle in thermal power plant.

a. Used of high pressure

b.  Reheating of steam at intermediate stag

c.  Regeneration use of steam for heating boiler

d.  All of these

Which of the following primarily involves heat transfer by convection?

1. Heat transfer from hand to the ice

2. Heating of surface of a boiler

3. Heating of liquid from a heat source

4. Heating of roads by Sun

Which of the following involves a decrease in entropy?

1. Freezing of liquid water into ice

2. Conversion of water into steam

3. Conversion of ice into water

4. Evaporative heating of water

Which of the following statements about using geothermal energy is not true?

1. Geothermal energy is a non-conventional source of energy

2. Geothermal energy is used as a fuel for vehicles

3. Geothermal energy is used to generate electricity

4. Geothermal energy is the internal heat of the earth