Mechanical Engineering Multiple Choice Questions and Answers for Practice

16. During adiabatic process

1. work transfer is zero
2. enthalpy change is zero.
3. heat transfer is zero
4. enthalpy remains constant

17. During compression process which parameter will change?

1. Density
2. All Of above
3. Pressure
4. Volume

18. For earth moving machines, widely used engines are:

1. Diesel engine
2. Gas engine
3. Petrol engine
4. Steam engine

19. Function of piston rings is

1. To maintain a gas tight between the piston and the cylinder
2. To convert reciprocating motion into rotary motion
3. To connect piston and connecting road
4. To transmit force from piston to crank

20. If xl and x2 are the dryness fractions obtained in separating calorimeter and throttling calorimeter respectively, then actual dryness fraction of steam is

1. X1 + X2
2. X1 * X2
3. XI - X2
4. XI + X2 /2

21. In a IC engine from which of the following source energy is converted into mechanical energy

1. kinetic energy
2. All of the above
3. Chemical energy of fuel.
4. potential energy

22. In a simple gear train having two gears, if driving gear rotates in clockwise direction then driven gear rotates in

1. Depend on size of gear
2. depend on no. of teeth
3. Clockwise direction
4. Anti clockwise direction

23. In a two stroke cycle engine, one cycle is completed in the following number of revolutions of the crank shaft

1. 1
2. 4
3. 2
4. 3

24. In diesel cycle, heat is added at

1. constant volume
2. constant pressure
3. constant temperature
4. constant enthalpy

25. In Following which is the power producing device?

1. Compressor
2. Air Conditioner
3. Pump
4. I.C. Engine

26. In multi stage compression as compared to single stage compression the volumetric efficiency is

1. Constant
2. None of the above
3. more
4. less

27. In S.I. unit for the force is.

1. Newton
2. Lb
3. Kgm
4. Kgf

28. In the Polytropic Process PVⁿ= C, if n = infinity , the process is called

1. isothermal
2. adiabatic
3. isochoric
4. isobaric

29. Main disadvantage of nuclear energy is

1. Waste disposal
2. All of above
3. High operating cost
4. Low efficiency

30. Natural fuel is

1. Prepared fuel
2. None of the above
3. That occur in nature
4. Known as secondary fuel