61
Reynolds number is significant in
A)
supersonics, as with projectile and jet propulsion
B)
full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc
C)
simultaneous motion through two fluids where there is a surface of dis-continuity, gravity forces, and wave making effect, as with ship’s hulls
D)
all of the above
Answer & Solution
Answer: Option
B
62
Mach number is significant in
A)
supersonics, as with projectiles and jet propulsion
B)
full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc
C)
simultaneous motion through two fluids where there is a surface of dis-continuity, gravity force, and wave making effects, as with ship’s hulls
D)
all of fhe above
Answer & Solution
Answer: Option
A
63
A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?
A)
the metal piece will simply float over the mercury
B)
the metal piece will be immersed in mercury by half
C)
whole of the metal piece will be immersed with its top surface just at mercury level
D)
metal piece will sink to the bottom
Answer & Solution
Answer: Option
C
64
The viscosity of a gas
A)
decreases with increase in temperature
B)
increases with increase in temperature
C)
is independent of temperature
D)
is independent of pressure for very high pressure intensities
Answer & Solution
Answer: Option
B
65
The pressure at the summit of a syphon is
A)
equal to atmospheric
B)
less than atmospheric
C)
more than atmospheric
D)
none of the above
Answer & Solution
Answer: Option
B
66
In a free vortex motion, the radial component of velocity everywhere is
A)
maximum
B)
minimum
C)
zero
D)
non-zero and finite
Answer & Solution
Answer: Option
C
67
A fluid in equilibrium can’t sustain
A)
tensile stress
B)
compressive stress
C)
shear stress
D)
bending stress
Answer & Solution
Answer: Option
C
68
The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to
A)
2100
B)
2700
C)
10,000
D)
21,000
Answer & Solution
Answer: Option
D
69
If velocity is zero over $${\frac{1}{3}^{{\text{rd}}}}$$ of a cross-section and is uniform over remaining $${\frac{2}{3}^{{\text{rd}}}}$$ of the cross-section, then the correction factor for kinetic energy is
A)
$$\frac{4}{3}$$
B)
$$\frac{3}{2}$$
C)
$$\frac{9}{4}$$
D)
$$\frac{{27}}{8}$$
Answer & Solution
Answer: Option
C
70
With the same cross-sectional area and immersed in same turbulent flow, the largest total drag will be on
A)
a circular disc of plate held normal to flow
B)
a sphere
C)
a cylinder
D)
a streamlined body
Answer & Solution
Answer: Option
A
