Engineering Questions with Answers - Multiple Choice Questions

# Fluid Mechanics MCQ – Pipes in Series

1 - Question

The liquid flowing through a series of pipes can take up__________
a) Pipes of different diameters
b) Pipes of the same diameters only.
c) Single pipe only
d) Short pipes only

Explanation: When pipes of different diameters are connected at its ends to form a pipe, this pipe so developed is called as pipes in series. They might not have to be of the same diameters. But, having the same diameters are better as it avoids the losses so developed.

2 - Question

What is the total loss developed in a series of pipes?
a) Sum of losses in each pipe only
b) Sum of local losses only
c) Sum of local losses plus the losses in each pipe
d) Zero

Explanation: When the pipes of different diameters are connected in series from end to end to form a pipe line. The total loss so developed is equal to the sum of local losses plus the losses in each pipe. The local losses are developed at the connection point.

3 - Question

The total head loss for the system is equal to_________
a) Pipe length
b) Pipe diameter
c) Width of the reservoir
d) Height difference of reservoirs

Explanation: Total head loss for a system is equal to the height difference of the reservoirs. Height difference is denoted by the letter ‘H’. Total head loss can be equated by summing it up with all the local losses and the losses at each pipe.

4 - Question

Which among the following is not a loss that is developed in the pipe?
a) Entry
b) Exit
c) Connection between two pipes
d) Liquid velocity

Explanation: Liquid velocity in the pipe is the velocity with which the liquid travels through different cross sections of the pipe. It is a vector field which is used to describe the motion of a continuum. The length of flow velocity vector is equal to the flow speed.

5 - Question

Which among the following is the correct formula for head loss?
a) Z1-Z2
b) C
c) T2-T1
d) S2-S1

Explanation: Total head loss for a system is equal to the height difference of the reservoirs. Height difference is denoted by the letter ‘H’. Total head loss can be equated by summing it up with all the local losses and the losses at each pipe. Here, the height difference between the reservoirs is Z1-Z2.

6 - Question

If the two reservoirs are kept at the same level, the head loss is _______
a) Z1-Z2
b) Zero
c) T2-T1
d) S2-S1

Explanation: Total head loss for a system is equal to the height difference of the reservoirs. Height difference is denoted by the letter ‘H’. The height difference between the reservoirs is Z1-Z2. Since they are of the same level, Z1=Z2. Therefore, head loss is zero.

7 - Question

How do we determine the total discharge through parallel pipes?
b) Subtract them
c) Multiply them
d) Divide them

Explanation: Total discharge in parallel pipes are determined by adding the discharges so developed in individual pipes. If Q1 is the discharge through pipe 1 and Q2 is the discharge through pipe 2. Then the total discharge through parallel pipes is equal to Q1+Q2.

8 - Question

The pipe diameter is ________
a) Directly proportional to fluid density
b) Directly proportional to mass flow rate
c) Inversely proportional to mass flow rate
d) Directly proportional to fluid velocity

Explanation: The pipe diameter is directly proportional to mass flow rate of fluid. Pipe diameter can be calculated if volumetric flow rate and velocity are known. ‘D’ is inversely proportional to its velocity.

9 - Question

Define Viscosity.
a) Resistance to flow of object
b) Resistance to flow of air
c) Resistance to flow of fluid
d) Resistance to flow of heat

Explanation: Viscosity is developed due to the relative motion between two surfaces of fluids at different velocities. It happens due to the shear stress developed on the surface of the fluid.

10 - Question

Coefficient of friction of a laminar flow is_________
a) Re/16
b) Re/64
c) 16/Re
d) 64/Re