1.In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the

A. Reynold's number

B. Grashoff's number

C. Reynold's number, Grashoff's number

D. Prandtl number, Grashoff's number

2.A regenerative steam cycle renders

A. increased work output per unit mass of steam

B. decreased work output per unit mass of steam

C. increased thermal efficiency

D. decreased work output per unit mass of steam as well as increased thermal efficiency

3.In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in __________ of the piston.

A. one stroke

B. two strokes

C. three strokes

D. four strokes

4.The type of rotary compressor used in gas turbines, is of

A. centrifugal type

B. axial flow type

C. radial flow type

D. none of these

5.The difference between dry bulb temperature and wet bulb temperature, is called

A. dry bulb depression

B. wet bulb depression

C. dew point depression

D. degree of saturation

6.The heat transfer takes place according to

A. Zeroth law of thermodynamics

B. First law of thermodynamics

C. Second law of thermodynamics

D. Kirchhoff's law

7.The coefficient of performance is always __________ one.

A. equal to

B. less than

C. greater than

8.For the same compression ratio, the efficiency of dual combustion cycle is

A. greater than Diesel cycle and less than Otto cycle

B. less than Diesel cycle and greater than Otto cycle

C. greater than Diesel cycle

D. less than Diesel cycle

9.The flow of steam is super-sonic

A. at the entrance to the nozzle

B. at the throat of the nozzle

C. in the convergent portion of the nozzle

D. in the divergent portion of the nozzle

10.The specific humidity during heating and humidification process.

A. remains constant

B. increases

C. decreases

11.The minimum temperature to which water can be cooled in a cooling tower is

A. dew point temperature of air

B. wet bulb temperature of air

C. dry bulb temperature of air

D. ambient air temperature

12.When the temperature of the surrounding is higher than the temperature of the body, then the heat loss by convection from the body to the surrounding will be

A. positive

B. negative

C. zero

D. none of these

13.The principal constituents of a fuel are

A. carbon and hydrogen

B. oxygen and hydrogen

C. sulphur and oxygen

D. sulphur and hydrogen

14.The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is always __________ one.

A. equal to

B. less than

C. greater than

15.In a vapour compression system, the condition of refrigerant before passing through the condenser is

A. saturated liquid

B. wet vapour

C. dry saturated vapour

D. superheated vapour

16.The critical temperature is the temperature

A. below which a gas does not obey gas laws

B. above which a gas may explode

C. below which a gas is always liquified

D. above which a gas will never liquefied

17.The behaviour of super-heated vapour is similar to that of

A. perfect gas

B. air

C. steam

D. ordinary gas

18.For the constant pressure and heat input, the air standard efficiency of gas power cycle is in the order

A. Dual cycle, Diesel cycle, Otto cycle

B. Otto cycle, Diesel cycle, Dual cycle

C. Dual cycle, Otto cycle, Diesel cycle

D. Diesel cycle, Otto cycle, Dual cycle

19.The artificial draught is produced by

A. steam jet

B. centrifugal fan

C. chimney

D. both (a) and (b)

20.The coefficient of performance (C.O.P.) of a refrigerator working as a heat pump is given by

A. (C.O.P.)P = (C.O.P.)R + 2

B. (C.O.P.)P = (C.O.P.)R + 1

C. (C.O.P)P = (C.O.P)R - 1

D. (C.O.P)P = (C.O.P)R

21.Thermal conductivity of solid metals __________ with rise in temperature.

A. remains same

B. decreases

C. increases

22.The coefficient of performance of a domestic refrigerator is __________ as compared to a domestic air-conditioner.

A. same

B. less

C. more

23.Which of the following is the extensive property of a thermodynamic system?

A. Pressure B. Volume

C. Temperature D. Density

24.The emissivity for a black body is

A. 0 B. 0.5

C. 0.75 D. 1

25.The volumetric efficiency of a compressor

A. increases with decrease in compression ratio

B. decreases with decrease in compression ratio

C. increases with increase in compression ratio

D. decreases with increase in compression ratio

26.The fuel mostly used in steam boilers is

A. brown coal

B. peat

C. coking bituminous coal

D. non-coking bituminous coal

27.A close cycle gas turbine gives __________ efficiency as compared to an open cycle gas turbine.

A. same

B. lower

C. higher

28.The increase in entropy of a system represents

A. increase in availability of energy

B. increase in temperature

C. decrease in pressure

D. degradation of energy

29.The expression Q = ρ AT4 is called

A. Fourier equation

B. Stefan-Boltzmann equation

C. Newton-Rikhmann equation

D. Joseph-Stefan equation

30.The amount of heat flow through a body by conduction is

A. directly proportional to the surface area of the body

B. directly proportional to the temperature difference on the two faces of the body

C. inversely proportional to the thickness of the body

D. all of the above