# MCQ on Fluid Mechanics

**MCQ on Fluid Mechanics**

**1-Rain drops are spherical
because of:**

(A) viscosity

(B) air resistance

(C) surface tension

(D) atmospheric pressure

**2-An ideal fluid is one
which**

(A) Obeys Newton’s law of viscosity

(B) Flows through pipes with least friction

(C) is frictionless and incompressible

(D) satisfies continuity equation

**3-Bernolli’s equation deals
with the principal of conservation of:**

(A) Momentum

(B) Energy

(C) Mass

(D) Force

**4-Standard atmospheric
pressure in terms of water column is:**

(A) 9.81 m

(B) 8.75 m

(C) 12.35 m

(D) 10.33 m

**5-The essential feature of
turbulent flow:**

(A) Large discharge

(B) High discharge

(C) Velocity at a point remains constant with time

(D) Velocity and pressure at a point exhibits irregular fluctuations of high frequency

**6-The laminar flow is
characterized by:**

(A) Irregular motion of fluid particle

(B) Fluid particle moving in layers parallel to the boundary surface

(C) Existence of eddies

(D) High Reynold’s number of flow

**7-Venturi meter is a device
used for measuring**

(A) Flow rate

(B) Piezo metric head

(C) Velocity head

(D) Pressure

**8-Gauge pressure at a point
is equal to:**

(A) Absolute pressure minus atmospheric pressure

(B) Absolute pressure plus atmospheric pressure

(C) Vacuum pressure plus absolute pressure

(D) Vacuum pressure minus atmospheric pressure

**9-The discharge through a
rectangular notch is given by**

(A)
Q = 2/3[C_{d}L(2g)^{1/2}H^{5/2}]

(B)
Q = 8/15[C_{d}L(2g)^{1/2}H^{3/2}]

(C)
Q = 8/15[C_{d}L(2g)^{1/2}H^{5/2}]

(D)
Q = 2/3[C_{d}L(2g)^{1/2}H^{3/2}]

**10-The co-efficient of
discharge C _{d} in terms of C_{v} and C_{c}:**

(A)
C_{d} = C_{v}/C_{c}

(B)
C_{d} = C_{v} x C_{c}

(C)
C_{d} = C_{c}/C_{v}

(D) None of the above

**11-The unit of kinematic
viscosity is:**

(A)
m^{3}/s

(B)
m^{2}/s

(C)
m/s^{2}

(D) m/s

**12-The fluid pressure,
exerted upon a column of liquid, can be measured by an instrument called:**

(A) Pressure gauge

(B) Venturi meter

(C) Manometer

(D) Energy meter

**13-Give an example for
positive displacement pump: **

(A) Piston pump

(B) Jet pump

(C) Centrifugal pump

(D) Propeller pump

**14-Working of orifice meter
is based on**

(A) Pascal’s law

(B) Bernoulli’s theorem

(C) Stoke’s law

(D) Archimedes principle

**15-For a cylindrical pipe of
diameter d, the hydraulic mean depth ‘m’ is equal to**

(A) 4d

(B) 2d

(C) d/4

(D) d/2

**16-Water is flowing with a
velocity 4m/s ^{2} in a pipe line of diameter 8 cm. The diameter
suddenly reduced to 2 cm, what is its corresponding velocity?**

(A)
8 m/s^{2}

(B)
16 m/s^{2}

(C)
32 m/s^{2}

(D)
64 m/s^{2}

**17-One stoke is equal to:**

(A)
10^{-4} m^{2}/s

(B)
10^{-3} m^{2}/s

(C)
10^{-2} m^{2}/s

(D)
10^{-1} m^{2}/s

**18-Steady flow occurs when:**

(A) velocity does not change

(B) pressure does not change

(C) conditions change gradually with time

(D) conditions do not change with time at any point

**19-Pressure in Pascal at a
depth of 0.5m below the free surface of water will be**

(A) 0.5 Pa

(B) 4905 Pa

(C) 9810 Pa

(D) 981 Pa

**20-Newtons law of viscosity
states:**

(A) shear stress is directly proportional to velocity

(B) shear stress is directly proportional to velocity gradient

(C) shear stress is directly proportional to shear strain

(D) shear stress is directly proportional to viscosity

**21-The term v ^{2}/2g
is known as**

(A) velocity head

(B) pressure head

(C) potential head

(D) none of the above

**22-Notch is a device used
for measuring**

(A) rate of flow through pipes

(B) rate of flow through small channels

(C) velocity through pipes

(D) velocity through small channels

**ANSWERS:**

**1-(C), 2-(C), 3-(B), 4-(D), 5-(D), 6-(B), 7-(A), 8-(A), 9-(D), 10-(A), 11-(B), 12-(C), 13-(A), 14-(B), 15-(C), 16-(D), 17-(A), 18-(A), 19-(B), 20-(B), 21-(A), 22-(B)**