NEET Physics Fluid Flow Reynolds Number and Bernoull is Principle MCQs

a) 3.81 × 10⁵ N/m²

b) 6 × 10⁶ N/m²

c) 5 × 10⁷ N/m²

d) 4.6 × 10² N/m²

Answer: 3.81 × 10⁵ N/m²

Question: Figure shows a U-tube of uniform cross-sectional area A, accelerated with acceleration a as shown. If d is the separation between the limbs, then what is the difference in the levels of the liquid in the U-tube is

a)

b)

c)

d)

Answer:

Question: Beyond the critical speed, the flow of fluids becomes

a) turbulent

b) very slow

c) streamline

d) steady

Answer: turbulent

Question: Streamline flow is more likely for liquids with

a) low density and high viscosity

b) high density and low viscosity

c) high density and high viscosity

d) low density and low viscosity

Answer: low density and high viscosity

Question: For flow of a fluid to be turbulent

a) both

b) fluid should have high density

c) velocity should be large

d) None of these

Answer:  both

Question:  In Bernoulli’s theorem which of the following is conserved?

a) Energy

b) Mass

c) Linear momentum

d) Angular momentum

Answer: Energy

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

a) the speed is low at the wider end and high at the narrow end.

b) the speed is same at both ends in a stream line flow

c) the liquid flows with uniform velocity in the tube.

d) the speed is high at the wider end and high at the narrow end

Answer: the speed is low at the wider end and high at the narrow end.

Question: Which of the following statements are true about streamline flow?
I. Path taken by a fluid particle under a steady flow is a streamline
II. No two streamlines can cross each other
III. Velocity increases at the narrower portions where the streamlines are closely spaced

a) I, II & III

b) II & III only

c) I & II only

d) I & III only

Answer: I, II & III

Question: Consider the following statements : In a streamline flow of a liquid
I. the kinetic energies of all particles arriving at a given point are same.
II. the momenta of all particles arriving at a given point are same.
III. the speed of particles are below the critical velocity.
Which of the statements given above are correct?

a) I, II & III

b) II & III only

c) I & II only

d) I &III only

Answer:  I, II & III

Question: A liquid flows through a tube of uniform cross-section with a constant speed in the direction as shown by the arrows in fig. The liquid exerts on the tube

a) an anticlockwise torque

b) a net force to the right

c) a net force to the left

d) a clockwise torque

Answer: an anticlockwise torque

Question:  Water flows through a frictionless tube with a varying crosssection as shown in fig. Pressure P at points along the axis is represented by

a)

b)

c)

d)

Answer:

Question: Air flows horizontally with a speed v = 106 km/hr. A house has plane roof of area A = 20m². The magnitude of aerodynamic lift of the roof is

a) 1.127 × 10⁴ N

b) 1.127 × 10⁵ N

c) 5.0 × 10⁴ N

d) 3.127 × 10⁴ N

Answer:  1.127 × 10⁴ N

Question: In which flow the velocity of fluid particles reaching a particular point is same at all time?

a) steady flow

b) turbulant flow

c) None of these

d) vigrous flow

Answer: steady flow

Question:

a) 2.4 × 10⁵ N, upwards

b) 4.8 × 10⁵ N, downwards

c) 4.8 × 10⁵ N, upwards

d) 2.4 × 10⁵ N, downwards

Answer: 2.4 × 10⁵ N, upwards

Question: Assertion : Lifting of aircraft is caused by pressure difference brought by varying speed of air molecules.
Reason : As the wings/ aerofoils move against the wind, the streamlines crowd more above them than below, causing higher velocity above than below.

a) Assertion is correct, reason is correct; reason is a correct explanation for assertion

b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

c) Assertion is correct, reason is incorrect

d) Assertion is incorrect, reason is correct

Answer:  Assertion is correct, reason is correct; reason is a correct explanation for assertion

Question:

a)

b)

c) Both

d) None of these

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question: In Bernoulli’s theorem which of the following is conserved?

a) None of these

b) Mass

c) Linear momentum

d) Angular momentum

Answer: None of these

Question: In which flow the velocity of fluid particles reaching a particular point is same at all time?

a) None of these

b) turbulant flow

c) Both

d) vigrous flow

Answer:  None of these