Mechanical Engineering Questions

23-The concept of boundary layer is introduced by

(A) Prandtl

(B) Reynold

(C) Euler

(D) Nusselt

 

24-A broach has the following teeth

(A) Rough teeth

(B) Semi-finishing teeth

(C) Finishing teeth

(D) All of the above

 

25-Corrosion resistance of steel is increased by adding

(A) Carbon

(B) Manganese

(C) Magnesium

(D) Chromium

 

26-The loss of head (or energy) due to velocity of liquid at the outlet of the pipe is given as

(A) V4/4g

(B) V4/2g

(C) V2/4g

(D) V2/2g

 

27-The strain energy stored in a body when the load is gradually applied is

(Where V=Volume of body, σ=stress in the body, E=Young’s modulus)

(A) σE/V

(B) σV/E

(C) σ2 E/2V

(D) σ2 V/2E

 

28-Mild steel is a

(A) low carbon steel

(B) medium carbon steel

(C) high carbon steel

(D) high speed steel

 

29-The flow of fluid through pipe is laminar when

(A) the fluid is ideal

(B) the fluid is viscous

(C) the reynold’s number is less than 2000

(D) there is considerable lateral dispersion

 

30-The hoop stress in a thin cylinder is

(A) Half of the longitudinal stress

(B) equal to longitudinal stress

(C) twice the longitudinal stress

(D) four times the longitudinal stress

 

31-As per uniform wear theory, brakes and clutches friction radius is equal to

(A) (R+r)/2

(B) (R2+r2)/2

(C) (R2+r2)/2Rr

(D) R+r

 

32-An alloy of copper, tin and zinc is known as

(A) Brass

(B) Bronze

(C) Muntz metal

(D) Gun metal

 

33-The following is an antifriction bearing

(A) Journal bearing

(B) Sleeve bearing

(C) Foot step bearing

(D) Ball and roller bearing

 

ANSWERS:

23-(A), 24-(D), 25-(D), 26-(D), 27-(D), 28-(A), 29-(C), 30-(C), 31-(D), 32-(B), 33-(D)