This set of Fluid Mechanics Questions and Answers for Aptitude test focuses on “Time Required to Empty a Reservoir Or a Tank with a Rectangular, Triangular & Cipolletti Weir or Notch”.
1. What is the reduction in crest length due to each end contraction?
a) 0.1H
b) 0.2H
c) 0.15H
d) 0.25H
View Answer
Explanation: Francis through his experiment had derived this empirical relation.
2. In Francis formula, the effective length is –
a) L-0.2H
b) L-0.4H
c) L-0.3H
d) L-0.1H
View Answer
Explanation: In Francis formula, the effective length is L-0.2H.
3. In Francis empirical expression for discharge, the relation between head of water and discharge is
a) Q is directly proportional to H
b) Q is directly proportional to H1.5
c) Q is directly proportional to H2.5
d) Q is directly proportional to H0.5
View Answer
Explanation: In Francis empirical expression for discharge, the relation between head of water and discharge is Q is directly proportional to H1.5.
4. In Bazin’s formula, the discharge is inversely proportional to the length of weir.
a) True
b) False
View Answer
Explanation: In Bazin’s formula, the discharge is directly proportional to the length of weir.
5. The head of water over a rectangular weir is 38 cm. The length of the crest of the weir end contraction suppressed is 1.3 m. Find the discharge using the Francis formula.
a) 0.56 m3/s
b) 0.75 m3/s
c) 0.85 m3/s
d) 0.69 m3/s
View Answer
Explanation: Q = 1.84*L*H1.5 = 0.56 m3/s.
6. The head of water over a rectangular weir is 28 cm. The length of the crest of the weir end contraction suppressed is 1.27 m. Find the discharge using the Francis formula.
a) 0.346 m3/s
b) 0.556 m3/s
c) 0.788 m3/s
d) 0.225 m3/s
View Answer
Explanation: Q = m * L * (2*g)0.5 * H1.5
m = ⅔ * Cd
= 0.405 + 0.003/H
= 0.405 + 0.003/0.28
Q = 0.346 m3/s.
7. The head of water over a rectangular weir is 26 cm. The length of the crest of the weir end contraction suppressed is 1.25 m. Find the discharge using the Francis formula.
a) 0.304 m3/s
b) 0.502 m3/s
c) 0.350 m3/s
d) 0.625 m3/s
View Answer
Explanation: Q = 1.84*L*H1.5
= 0.304 m3/s.
8. The head of water over a rectangular weir is 28 cm. The length of the crest of the weir end contraction suppressed is 1.27 m. Find the discharge using the Francis formula.
a) 0.346 m3/s
b) 0.556 m3/s
c) 0.788 m3/s
d) 0.225 m3/s
View Answer
Explanation: Q = m * L * (2*g)0.5 * H1.5
m = ⅔ * Cd
= 0.405 + 0.003/H
= 0.405 + 0.003/0.28
Q = 0.346 m3/s.
9. Find the discharge over a cipolletti weir of length 1.5 m when the head over the weir is 0.85 m. Take Cd = 0.61.
a) 2.12 m3/s
b) 1.25 m3/s
c) 2.5 m3/s
d) 1.5 m3/s
View Answer
Explanation: Q = ⅔ * Cd * L * (2g)0.5 * H1.5
= 2.12 m3/s.
10. Find the discharge over a cipolletti weir of length 1.3 m when the head over the weir is 0.65 m. Take Cd = 0.60.
a) 2.12 m3/s
b) 1.21 m3/s
c) 2.5 m3/s
d) 1.5 m3/s
View Answer
Explanation: Q = ⅔ * Cd * L * (2g)0.5 * H1.5
= 1.21 m3/s.
Sanfoundry Global Education & Learning Series – Fluid Mechanics.
To practice all areas of Fluid Mechanics for Aptitude test, here is complete set of 1000+ Multiple Choice Questions and Answers.
Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!
