## Fluid Mechanics Questions MCQs

### Total Questions : 745

Page 1 of 38 pages
Question 1. Velocity of liquid hydrocarbon fuels in a pipeline can not be measured by magnetic flowmeters, because their __________ is very low/small.
1.    Thermal conductivity
2.    Electrical conductivity
3.    Specific gravity
4.    Electrical resistivity
Question 2. For turbulent fluid flow in pipe, the expression for Prandtl one seventh power law is (where, r = pipe radius, x = distance).
1.    V/Vmax = (x/r)1/7
2.    V/Vmax = (r/x)1/7
3.    V/Vmax = (x.r)1/7
4.    None of these
Question 3. What is the force required (in Newtons) to hold a spherical balloon stationary in water at a depth of H from the air-water iterface? The balloon is of radius 0.1 m and is filled with air.
1.    4πg/3
2.    0.01πgH/4
3.    0.01πgH/8
4.    0.04πgH/3
Question 4. Capillary rise of mercury in a small diameter tube is proportional to (where, d = diameter of the tube, σ = surface tension of mercury)
1.    D
2.    1/d
3.    Σ
4.    L/σ
Question 5. With increase in molecular weight of the gas, the head developed by a centrifugal compressor will
1.    Decrease
2.    Increase
3.    Remain same
4.    Unpredictable
Question 6. Priming of a centrifugal pump is done to
1.    Increase the mass flow rate of fluid
2.    Develop effective pressure rise by the pump
3.    Avoid chances of separation inside the impeller
4.    None of these
Question 7. Pressure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as
1.    V1.8
2.    V-0.2
3.    V2.7
4.    V2
Question 8. __________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm².
1.    Centrifugal
2.    Piston
3.    Plunger
4.    Vane
Question 9. The terminal velocity of a small sphere settling in a viscous fluid varies as the
1.    First power of its dimeter
2.    Inverse of the fluid viscosity
3.    Inverse square of the diameter
4.    Square of the difference in specific weights of solid & fluid
Question 10. Pressure drop in a fluidised bed reactor is __________ that in a similar packed bed reactor.
1.    Less than
2.    More than
3.    Same as
4.    None of these
Question 11. Curve III in the above diagram represents a/an
1.    Dilatent fluid
2.    Pseudo plastic fluid
3.    Ideal plastic
4.    None of these
Question 12. A hydraulic ram acts as a/an __________ pump.
1.    Centrifugal
2.    Reciprocating
3.    Impulse
4.    Parallel cylinder
Question 13. The inherent characteristic of an equal percentage valve relating flow rate 'q' with valve stem movement 'x' are described by the equation
1.    dq/dx = K
2.    dq/dx = K.q
3.    dq/dx = K/q
4.    dq/dx = Kq²
Question 14. The capacity of an accumulator is the maximum
1.    Energy which it can store
2.    Discharge which it can deliver
3.    Liquid which it can store
4.    None of these
Question 15. What is the value of Fanning friction factor f ' for smooth pipe at NRe = 10⁶ approximately?
1.    0.003
2.    0.01
3.    0.1
4.    0.3
Question 16. For an unstable equilibrium of a floating body (where, M = metacentre.)
1.    M is above G
2.    M is below G
3.    M & G coincide
4.    None of these
Question 17. Drag force acting on a body does not depend upon the
1.    Density of the fluid
2.    Density of the body
3.    Velocity of the body
4.    Projected area of the body
Question 18. For an incompressible fluid, the bulk modulus of elasticity is
1.    5 kg/m³
2.    ∞ N/m²
3.    1 N
4.    0 N/m