Engineering Questions with Answers - Multiple Choice Questions
MCQs on Classification of Orifice & Hydraulic Coefficients
1 - Question
When is orifice called ‘large orifice’?
a) If the head of liquid is less than 5 times the depth of orifice
b) If the head of liquid is less than 2.5 times the depth of orifice
c) If the head of liquid is less Hence, 4 times the depth of orifice
d) If the head of liquid is less than 1.5 times the depth of orifice
View Answer
a
Explanation: It is the correct parametric definition for ‘large orifice’.
2 - Question
In case of any orifice, velocity always remains constant and hence discharge can be calculated.
a) True
b) False
View Answer
b
Explanation: In case of large orifice, velocity always remains variable and hence discharge cannot be calculated.
3 - Question
Find the discharge through a rectangular orifice 2.2 m wide and 1.3 m deep fitted to a easier tank. The water level in a team is 2.5 m above the top edge of orifice.
a) 13.9 m3/s
b) 11.5 m3/s
c) 16.9 m3/s
d) 8.7 m3/s
View Answer
a
Explanation: Q = 2/3 Cd *b*√2g* (H21.5 – H11.5)
Here,
H1 = 3.8
H2 = 2.5
b = 2.2
Hence, Q = 13.9 m3/s.
4 - Question
Find the discharge through a rectangular orifice 3.2 m wide and 1.7 m deep fitted to a easier tank. The water level in a team is 3.3 m above the top edge of orifice. Take Cd = 0.6
a) 29.4 m3/s
b) 58.5 m3/s
c) 67.9 m3/s
d) 78.7 m3/s
View Answer
a
Explanation: Q = 2/3 Cd *b*√2g* (H21.5 – H11.5)
Here,
H1 = 5
H2 = 3.3
b = 3.2
Hence, Q = 29.4 m3/s.
5 - Question
Find the discharge through totally drowned orifice of width 2.3 m if the difference of water levels on both side of the orifice be 40 cm. The height of water from to and bottom of the orifice are 2.6 m and 2.75 m respectively.
a) .56 m3/s
b) .64 m3/s
c) .75 m3/s
d) .55 m3/s
View Answer
a
Explanation: Q = Cd * b * (H2 – H1) √2gH
Here, b = 2.3
H2 = 2.75
H1 = 2.6
H = 40
Q = .56 m3/s.
6 - Question
Find the discharge through totally drowned orifice of width 3.3 m if the difference of water levels on both side of the orifice be 50 cm. The height of water from to and bottom of the orifice are 2.25 m and 2.67 m respectively.
a) 2.8 m3/s
b) 2.7 m3/s
c) 2.6 m3/s
d) 2.5 m3/s
View Answer
a
Explanation: Q = Cd * b * (H2 – H1) √2gH
Here, b = 3.3
H2 = 2.67
H1 = 2.25
H = 50
Q = 2.6 m3/s.
7 - Question
A rectangular orifice of 2 m width and 1.2 m deep is fitted in one side of large tank. The easier level on one side of the orifice is 3m above the top edge of the orifice while on the other side of the orifice the water level is 0.5 m below it’s top edge. Calculate discharge if Cd = .64
a) 4.95 m3/s
b) 5.67 m3/s
c) 3.56 m3/s
d) 6.75 m3/s
View Answer
a
Explanation: Explanation: Q = Cd * b * (H2 – H) √2gH
Here, b = 2
H2 = 4.2
H = 3.5
Q = 4.94 m3/s.
8 - Question
The time taken to empty the tank is independent of Cd but depends only on the height and acceleration due to gravity.
a) True
b) False
View Answer
b
Explanation: The time taken to empty the tank is dependent on Cd as well as depends only on the height and acceleration due to gravity.
9 - Question
The discharge rate is independent of the height difference and dependent only on the height.
a) True
b) False
View Answer
b
Explanation: The discharge rate is dependent of the height difference and dependent only on the height.
10 - Question
In case of submerged orifice the discharge is substantially dependent on temperature of fluid
a) True
b) False
View Answer
b
Explanation: Discharge is dependent on temperature but minimally.