Flow Through Pipes - Mechanical Engineering (MCQ) questions and answers

1)   Minor losses occur due to

a. sudden enlargement in pipe
b. sudden contraction in pipe
c. bends in pipe
d. all of the above
Answer  Explanation 

ANSWER: all of the above

Explanation:
No explanation is available for this question!


2)   What is Darcy-Weisbach formula for heat loss due to friction?

Where,
f = Darcy's coefficient of friction


a. hf = (f l V2) / (g d)
b. hf = (f l V2) / (2 g d)
c. hf = (4 f l V2) / (2 g d)
d. hf = (16 f l V2) / (2 g d)
Answer  Explanation 

ANSWER: hf = (4 f l V2) / (2 g d)

Explanation:
No explanation is available for this question!


3)   What is the formula for determining the size of equivalent pipe for two pipes of lengths L1, L2 and diameters d1, d2 respectively?

Where,
L = L1 + L2


a. (L / d) = (L1 / d1) + (L2 / d2)
b. (L / d2 ) = (L1 / d12) + (L2 / d22)
c. (L / d3) = (L1 / d13 ) + (L2 / d23)
d. (L / d5) = (L1 / d15 ) + (L2 / d25)
Answer  Explanation 

ANSWER: (L / d5) = (L1 / d15 ) + (L2 / d25)

Explanation:
No explanation is available for this question!


4)   What is the correct formula for loss at the exit of a pipe?

a. hL = 0.5 (V2 / 2g)
b. hL = (V2 / 2g)
c. hL = (2 V2 / g)
d. hL = (4 V2 / g)
Answer  Explanation 

ANSWER: hL = (V2 / 2g)

Explanation:
No explanation is available for this question!


5)   Minor losses do not make any serious effect in

a. short pipes
b. long pipes
c. both the short as well as long pipes
d. cannot say
Answer  Explanation 

ANSWER: long pipes

Explanation:
No explanation is available for this question!


6)   The highest point of syphon is called as

a. syphon top
b. summit
c. reservoir
d. none of the above
Answer  Explanation 

ANSWER: summit

Explanation:
No explanation is available for this question!


7)   What is a syphon?

a. A long bend pipe used to carry water from a reservoir at a higher level to another reservoir at a lower level when two reservoirs are separated by a hill
b. A long bend pipe used to carry water from a reservoir at a lower level to another reservoir at a higher level with some work input when two reservoirs are separated by a hill
c. A long bend pipe used to carry water from one reservoir to another reservoir when two reservoirs are at same elevation
d. Unpredictable
Answer  Explanation 

ANSWER: A long bend pipe used to carry water from a reservoir at a higher level to another reservoir at a lower level when two reservoirs are separated by a hill

Explanation:
No explanation is available for this question!


8)   What is the effect of change in Reynold's number on friction factor in turbulent flow?

a. As the Reynold's number increases the friction factor increases in turbulent flow
b. As the Reynold's number increases the friction factor decreases in turbulent flow
c. change in Reynold's number does not affect the friction factor in turbulent flow
d. unpredictable
Answer  Explanation 

ANSWER: As the Reynold's number increases the friction factor decreases in turbulent flow

Explanation:
No explanation is available for this question!


9)   The friction factor in fluid flowing through pipe depends upon

a. Reynold's number
b. relative roughness of pipe surface
c. both a. and b.
d. none of the above
Answer  Explanation 

ANSWER: both a. and b.

Explanation:
No explanation is available for this question!


10)   The head loss through fluid flowing pipe due to friction is

a. the minor loss
b. the major loss
c. both a. and b.
d. none of the above
Answer  Explanation 

ANSWER: the major loss

Explanation:
No explanation is available for this question!