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