MECHANICAL ENGINEERING MCQ SECTION 4

31. Casting of a centrifugal pump is designed to minimize

(A) friction loss

(B) cavitation

(C) static head

(D) loss of kinetic energy

32. In reaction turbine, draft tube is used

(A) to transport water downstream without eddies

(B) to convert the kinetic energy to flow energy by a

gradual expansion of the flow cross-section

(C) for safety of turbine

(D) to increase flow rate

33. Francis and Kaplan turbines fall under the category of

(A) Impulse turbines

(B) Reaction turbines

(C) Axial flow turbines

(D) Mixed flow turbines

34. Sensible heat is the heat required to

(A) change vapour into liquid

(B) change liquid into vapour

(C) increase the temperature of a liquid of vapour

(D) convert water into steam and superheat it

35. The following are the method for compounding except

(A) velocity compounding

(B) pressure compounding

(C) volume compounding

(D) none of these

36. Which of the following cycles uses air as the refrigerant?

(A) Ericsson

(B) Stirling

(C) Carnot

(D) Bell-Coleman

37. The refrigerant for a refrigerator should have

(A) high sensible heat

(B) high total heat

(C) high latent heat

(D) low latent heat

38. Refrigeration in Aeroplan’s usually employs the following refrigerant

(A) CO2

(B) Freon-11

(C) Freon-22

(D) Air

39. The bank of tubes at the back of domestic refrigerator are

(A) condenser tubes

(B) evaporator tubes

(C) refrigerant cooling tubes

(D) capillary tubes

40. The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft

(A) 1/2

(B) 1

(C) 2

(D) 4