EASY

Earn 100

Assertion: In the flow-tube as the cross-section area decreases the flow velocity increases.

Reason: In ideal fluid flow the total energy per unit mass remains constant.

50% studentsanswered this correctly

Important Questions on Fluid Dynamics

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

The cylindrical tube of a spray pump. having

30

holes each of diameter

1 mm,

has a crosssection of

6 {cm}^{2} .

If the liquid flow inside the tube is

1.2 m

per minute, then the speed of ejection of the liquid through the spray holes is

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

A liquid is allowed to flow into a tube of truncated cone shape. Identify the correct statement from the following.

HARD

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Mumbai needs

1.4 \times 10^{12} L

of water annually. Its effective surface area is

600 {km}^{2}

and it receives an average rainfall of

2.4 m

annually. If

10 %

of this rain water is conserved, it will meet approximately

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

The cylindrical tube of a spray pump has radius

R

, one end of which has

n

fine holes, each of radius

r

. If the speed of the liquid in the tube is

V

, the speed of the ejection of the liquid through the holes is :

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water from a tap emerges vertically downwards with an initial speed of

1.0 m s^{- 1}

. The cross

-

sectional area of the tap is

10^{- 4} m^{2}

. Assume that the pressure is constant throughout the stream of water and that the flow is streamlined. The cross

-

sectional area of the stream,

0.15 m

below the tap would be:
(Take

g = 10 m s^{- 2}

)

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

A vessel completely filled with water has holes

A

and

B

at depths

h

and

3 h

from the top respectively. The hole

A

is a square of side

L

and

B

is a circle of radius

r

. The water flowing out per second from both the holes is same. Then

L

is equal to

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water flows through a horizontal pipe at a speed

V

. Internal diameter of the pipe is

d

. If the water is emerging at a speed

V_{1}

the diameter of the nozzle is

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

The top of a water tank is open to air and its water level is maintained. It is giving out

0.74 m^{3}

water per minute through a circular opening of

2 cm

radius in its wall. The depth of the centre of the opening from the level of water in the tank is close to:

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water flows in a horizontal tube (see figure). The pressure of water changes by

700 N m^{- 2}

between

A

and

B

where the area of cross section are

40 {cm}^{2}

and

20 {cm}^{2},

respectively. Find the rate of flow of water through the tube. (density of water

= 1000 kg m^{- 3}

)

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

An ideal fluid flows (laminar flow) through a pipe of non-uniform diameter. The maximum and minimum diameters of the pipes are

6.4 c m

and

4.8 c m

, respectively. The ratio of the minimum and the maximum velocities of fluid in this pipe is:

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

What will be the nature of flow of water from a circular tap, when its flow rate increased from $0.18 L {(\min)}^{- 1}$ to $0.48 L {(\min)}^{- 1} ?$ The radius of the tap and viscosity of water are $0.5 cm$ and $10^{- 3} Pa s$ , respectively. (Density of water : $10^{3} kg m^{- 3}$ )

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water containing air bubbles flows without turbulence through a horizontal pipe which has a region of narrow cross-section. In this region the bubbles

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Two non-mixing liquids of densities

ρ

and

n ρ (n > 1)

are put in a container. The height of each liquid is

h.

A solid cylinder of length

L

and density

d

is put in this container. The cylinder floats with its axis vertical and length

p L (p < 1)

in the denser liquid. The density

d

is equal to:

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

A cylindrical tank has a hole of $1 {cm}^{2}$ in its bottom. If the water is allowed to flow into the tank from a tube above it at the rate of $70 {cm}^{3} s^{- 1}$ , then the maximum height up to which water can rise in the tank is_________

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water flows into a large tank with flat bottom at the rate of

10^{- 4} m^{3} s^{- 1} .

Water is also leaking out of a hole of area

1 c m^{2}

at its bottom. If the height of the water in the tank remains steady then this height is:

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

An aluminium sphere is dipped into water. Which of the following is true?

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

A small hole of area cross-section

2 m m^{2}

is present near the bottom of a fully filled open tank of height

2 m .

Taking

g = 10 m s^{- 2}

, the rate of flow of water through the open hole would be nearly

EASY

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water flows through a horizontal pipe of diameter

2 cm

at a speed of

3 cm s^{- 1}

. The pipe has a nozzle of diameter

0.5 cm

at its end. The speed of water emerging from the nozzle is

MEDIUM

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

Water is flowing at a speed of 1.5 m s^-1 through a horizontal tube of cross-sectional area 10^-2 m²and you are trying to stop the flow by your palm. Assuming that the water stops immediately after hitting the palm, the minimum force that you must exert should be (density of water = 10³ kg m^-3)

HARD

Physics>Mechanical Properties of Matter>Fluid Dynamics>Equation of Continuity

The Bhagirathi and the Alaknanda merge at Deoprayag to form the Ganga with their speeds in the ratio

1 : 1 : 5 .

The cross-sectional areas of the Bhagirathi, the Alaknanda and the Ganga are in the ratio

1 : 2 : 3 .

Assuming streamline flow, the ratio of the speed of Ganga to that of the Alaknanda is

Assertion: In the flow-tube as the cross-section area decreases the flow velocity increases. Reason: In ideal fluid flow the total energy per unit mass remains constant.

Important Questions on Fluid Dynamics

Learn and Prepare for any exam you want !

Assertion: In the flow-tube as the cross-section area decreases the flow velocity increases.

Reason: In ideal fluid flow the total energy per unit mass remains constant.