# Fluid Mechanics MCQ – Objective Questions & Answers

1. Which combination of the following statements about steady incompressible forced vortex flow is correct?
P: Shear stress is zero at all points in the flow
Q: Vorticity is zero at all points in the flow
R: Velocity is directly proportional to the radius from the centre of the vortex
Q: Total mechanical energy per unit mass is constant in the entire flow field
A) P and Q
B) R and S
C) P and R
D) P and S
Ans: B

2. Consider steady laminar incompressible axi-symmetric fully developed viscous flow through a straight circular pipe of constant cross – sectional area at Reynolds number of 5. The ration of inertia force to viscous force on a fluid particle is
A) 5
B) 1 / 5
C) 0
D) ∞
Ans: A

3. A phenomenon is modelled using N dimensional variable with K primary dimension. The number of non-dimensional variable is
A) K
B) N
C) N – K
D) N + K
Ans: C

4. The maximum velocity of a one dimensional incompressible fully developed viscous flow, between two fixed parallel plates is 6 m /s. The mean velocity (in m / s) of the flow is
A) 2
B) 3
C) 4
D) 5
Ans: C

5. A streamline and equipotential line in a flow field
A) Are parallel to each other
B) Are perpendicular to each other
C) Intersect at an acute angle
D) An identical
Ans: B

6. In order to have maximum power from a pelton turbine, the bucket speed must be
A) Equal to the jet speed
B) Equal to half of the jet speed
C) Equal to twice the jet speed
D) Independent of the jet speed
Ans: B