# Notches MCQ – Fluid Mechanics

1. Notches are used to measure

1. velocity
2. flow rate
3. pressure
4. all above
Answer
Answer. b

2. For which angle of triangular notch the discharge over it is maximum?

1. 45°
2. 30°
3. 90°
4. 60°
Answer
Answer. c

3. The discharge over a rectangular notch is

1. inversely proportional to H3/2
2. directly proportional to H3/2
3. inversely proportional to H5/2
4. directly proportion to H5/2
Answer
Answer. b

4. Which notch is preferred for measuring the low discharges?

1. triangular notch
2. rectangular notch
3. trapezoidal notch
4. parabolic notch
Answer
Answer. a

5. The discharge through a V-notch varies as

1. H
2. H1.5
3. H0.5
4. H2.5
Answer
Answer. d

6. The sheet of water flowing through a notch or weir is known as

1. Nappe
2. Crest notch
3. Crested weir
4. Crest
Answer
Answer. a

7. In any channel, notch is used to measure the following

1. discharge
2. pressure
3. velocity
4. static energy
Answer
Answer. a

8. Discharge Q in a triangular weir varies as

1. H1/2
2. H
3. H3/2
4. H5/2
Answer
Answer. d

9. Which notch is preferable for low flow rates?

1. Rectangular
2. Triangular
3. Both Rectangular and Triangular
4. None of these
Answer
Answer. b

10. In a 90° triangular notch, the error in the estimated discharge for a given head due to an error of 1% in cutting the vertex angle is

1. 1 %
2. zero
3. π/2 %
4. π %
Answer
Answer. b

11. If H is the head, the discharge through a V-notch varies

1. proportional to head (H)
2. inversely proportional to angle θ
3. inversely proportional to tan θ/2
4. proportional to H5/2
Answer
Answer. d

12. The discharge through a V-notch varies with the depth of water H as

1. H1/2
2. H3/2
3. H5/2
4. H-1/2
Answer
Answer. c

13. For maximum discharge over a triangular notch, the angle of the notch should be

1. 60°
2. 30°
3. 120°
4. 90°
Answer
Answer. d

14. Notch is used for measuring

1. velocity through a small channel
2. rate of flow through a pipe
3. velocity through a pipe
4. rate of flow through a small channel
Answer
Answer. d

15. Notch is a device used for measuring

1. rate of flow through pipes
2. rate of flow through a small channel
3. velocity through a pipe
4. velocity through a small channel
Answer
Answer. b

16. The rate of flow through a V-notch varies

1. H
2. H1/2
3. H5/2
4. H3/2
Answer
Answer. c

17. A triangular notch is more accurate measuring device than a rectangular notch

1. for low flow rates
2. for medium flow rates
3. for high flow rates
4. for all flow rates
Answer
Answer. a

18. The discharge over a rectangular notch is

1. directly proportional to H5/2
2. directly proportional to H3/2
3. inversely proportional to H3/2
4. inversely proportional to H5/2
Answer
Answer. b

19. The head over a 90° V-notch increases from 0.20 m to 0.40 m. The ratio of the new discharge to the original discharge is

1. 1.414
2. 2.000
3. 4.000
4. more than 4.000
Answer
Answer. d

20. The percentage error in the computed discharge over a triangular notch corresponding to an error of 1% in the measurement of the head over the notch, would be

1. 2.5
2. 2
3. 2.2
4. 1.5
Answer
Answer. a