1. Explain the reason that why big tyres are used in rear of vehicles.

Large tyres provide larger surface area touching the ground, thus providing the more pulling power. Basically tractors have larger rear tyres because tractors don’t have to operate at higher speeds, thus getting the same ground speed with larger tyres. Moreover gear ratios don’t have to be as high as b/c of the tyres.

2. What are the names given to constant temperature, constant pressure, constant volume, constant internal energy, constant enthalpy, and constant entropy processes?.

Isothermal, isochroic, isobaric, free expression, throttling and adiabatic processes respectively.

3. In a Rankine cycle if maximum steam pressure is increased keeping steam temperature and condenser pressure same, what will happen to dryness fraction of steam after expansion ?

It will decrease.

4. Why entropy change for a reversible adiabatic process is zero ?

Because there is no heat transfer in this process.

5. What are two essential conditions of perfect gas ?

It satisfies equation of state and its specific heats are constant.

6. Enthalpy and entropy are functions of one single parameter. Which is that ?

Temperature.

7. Why rate of condensation is higher on a polished surface compared to rusty surface?

Polished surface promotes drop wise condensation and does not wet the surface.

8. How much resistance is offered to heat flow by drop wise condensation ?

Nil

9. What is the relationship between COP of heating and cooling ?

COP of heating is one(unity) more than COP of cooling.

10. How much is the work done in isochoric process ?

Zero.