NEET Physics Fluid Flow Reynolds Number and Bernoull is Principle MCQs

Question. Beyond the critical speed, the flow of fluids becomes
(a) turbulent
(b) very slow
(c) streamline
(d) steady

Answer: A

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: A

Question. For flow of a fluid to be turbulent
(a) velocity should be large
(b) fluid should have high density
(c) both
(d) None of these

Answer: A

Question.  In Bernoulli’s theorem which of the following is conserved?
(a) Energy
(b) Mass
(c) Linear momentum
(d) Angular momentum

Answer: A

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: A

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: A

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: A

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: A

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: A

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: A

Question. In Bernoulli’s theorem which of the following is conserved?
(a) None of these
(b) Mass
(c) Linear momentum
(d) Angular momentum

Answer: A

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: A