Fluid Statics and Dynamics MCQs

Question 1

In steady (streamline or laminar) flow:

Accepted Answer

the velocity of the fluid at each point does not change with time

Answer

the speed is zero everywhere

Answer

the fluid swirls in eddies

Answer

the fluid moves randomly

Question 2

Superfluid helium can flow through tiny pores that ordinary liquids:

Accepted Answer

cannot pass through

Answer

evaporate in

Answer

pass through faster

Answer

fill instantly

Question 3

If a pipe has no leaks and the flow is steady, the mass entering per second equals:

Accepted Answer

the mass leaving per second

Answer

zero

Answer

twice the mass leaving

Answer

the mass of the pipe

Question 4

Why does a ball of clay sink but the same clay shaped as a boat float?

Accepted Answer

the boat shape displaces more water, giving more upthrust

Answer

the boat traps heat

Answer

the boat shape has less mass

Answer

the clay becomes less dense

Question 5

A Venturi meter measures:

Accepted Answer

the speed of flow from the pressure difference between wide and narrow sections

Answer

the density of a solid

Answer

temperature

Answer

voltage

Question 6

A ship floats lower in fresh water than in sea water because:

Accepted Answer

fresh water is less dense, so more volume must be displaced

Answer

fresh water is denser

Answer

the ship becomes heavier

Answer

gravity is stronger on rivers

Question 7

Water flows at 3 m/s through a pipe of cross-section 0.002 m^2. The volume flow rate is:

Accepted Answer

0.006 m^3/s

Answer

6 10^-4 m^3/s

Answer

0.06 m^3/s

Answer

0.012 m^3/s

Question 8

Water leaks through a small hole 5 m below the surface of an open tank. The speed of efflux is (g = 9.8):

Accepted Answer

9.9 m/s

Answer

14 m/s

Answer

19.8 m/s

Answer

4.95 m/s

Question 9

A river flows faster where it is:

Accepted Answer

narrow and shallow

Answer

wide and deep

Answer

at rest

Answer

frozen

Question 10

Life jackets help a person float because they:

Accepted Answer

add a large volume with little weight, increasing upthrust

Answer

reduce the density of water

Answer

make the person heavier

Answer

increase the density of the person

Question 11

Blood flows faster in the aorta than in the capillaries because:

Accepted Answer

the total cross-sectional area of all capillaries is much larger

Answer

capillaries are wider individually

Answer

the heart stops

Answer

blood is compressed

Question 12

Archimedes' principle states that the upthrust on a body in a fluid equals:

Accepted Answer

the weight of fluid displaced

Answer

the volume of the body

Answer

the density of the fluid

Answer

the weight of the body

Question 13

A filter pump (water aspirator) creates suction because:

Accepted Answer

fast water through a narrow nozzle lowers the pressure, drawing air in

Answer

it heats the air

Answer

it uses magnets

Answer

it compresses the water

Question 14

The quantity Av represents:

Accepted Answer

the volume of fluid passing per second

Answer

the kinetic energy

Answer

the pressure

Answer

the mass of the pipe

Question 15

Water flows at 2 kg/s into a pipe junction and leaves through two branches. One branch carries 0.5 kg/s. The other carries:

Accepted Answer

1.5 kg/s

Answer

2.5 kg/s

Answer

1 kg/s

Answer

0.5 kg/s

Question 16

Which is NOT an example of the Bernoulli effect?

Accepted Answer

a ship floating in water

Answer

lift on an aircraft wing

Answer

a perfume atomiser

Answer

a roof blown off in a storm

Question 17

The tangent to a streamline at any point gives:

Accepted Answer

the direction of the fluid velocity there

Answer

the viscosity

Answer

the pressure

Answer

the density

Question 18

A skydiver reaches terminal velocity because:

Accepted Answer

air drag increases with speed until it balances weight

Answer

mass decreases

Answer

the air pushes upward more than weight

Answer

gravity stops acting

Question 19

Water leaves a hose of area 2 cm^2 at 4 m/s. Squeezed to 0.5 cm^2, it leaves at:

Accepted Answer

16 m/s

Answer

1 m/s

Answer

8 m/s

Answer

2 m/s

Question 20

A football kicked with sidespin curves because:

Accepted Answer

of the pressure difference caused by spin (Magnus effect)

Answer

of gravity alone

Answer

the ball changes mass

Answer

the wind always blows

Question 21

Which statement about ideal and real fluids is correct?

Accepted Answer

Ideal fluids have zero viscosity; real fluids have some viscosity

Answer

Both have infinite viscosity

Answer

Ideal fluids are very viscous

Answer

Real fluids have zero viscosity

Question 22

A beaker of superfluid helium partly dipped in a bath will:

Accepted Answer

have its level equalise with the bath through a creeping film

Answer

stay at a different level

Answer

freeze

Answer

boil away

Question 23

Superfluidity is a:

Accepted Answer

quantum mechanical effect at very low temperature

Answer

property of all liquids

Answer

high-temperature effect

Answer

magnetic effect

Question 24

Squeezing a hose to half its outlet area changes the exit speed from 3 m/s to:

Accepted Answer

6 m/s

Answer

3 m/s

Answer

1.5 m/s

Answer

12 m/s

Question 25

For a compressible fluid, continuity is written as:

Accepted Answer

rho1A1v1 = rho2A2v2

Answer

P1A1 = P2A2

Answer

rho1v1 = rho2v2

Answer

A1v1 = A2v2

Fluid Statics and Dynamics MCQs — Physics (page 4)

76. In steady (streamline or laminar) flow:

77. Superfluid helium can flow through tiny pores that ordinary liquids:

78. If a pipe has no leaks and the flow is steady, the mass entering per second equals:

79. Why does a ball of clay sink but the same clay shaped as a boat float?

80. A Venturi meter measures:

81. A ship floats lower in fresh water than in sea water because:

82. Water flows at 3 m/s through a pipe of cross-section 0.002 m^2. The volume flow rate is:

83. Water leaks through a small hole 5 m below the surface of an open tank. The speed of efflux is (g = 9.8):

84. A river flows faster where it is:

85. Life jackets help a person float because they:

86. Blood flows faster in the aorta than in the capillaries because:

87. Archimedes' principle states that the upthrust on a body in a fluid equals:

88. A filter pump (water aspirator) creates suction because:

89. The quantity Av represents:

90. Water flows at 2 kg/s into a pipe junction and leaves through two branches. One branch carries 0.5 kg/s. The other carries:

91. Which is NOT an example of the Bernoulli effect?

92. The tangent to a streamline at any point gives:

93. A skydiver reaches terminal velocity because:

94. Water leaves a hose of area 2 cm^2 at 4 m/s. Squeezed to 0.5 cm^2, it leaves at:

95. A football kicked with sidespin curves because:

96. Which statement about ideal and real fluids is correct?

97. A beaker of superfluid helium partly dipped in a bath will:

98. Superfluidity is a:

99. Squeezing a hose to half its outlet area changes the exit speed from 3 m/s to:

100. For a compressible fluid, continuity is written as:

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