1. The flow rate through a circular pipe is measured by

- pitot-tube
- venturimeter
- orifice meter
- none of the above

Code:

- i
- i, ii and iii
- ii and iii
- all of the above

2. The head loss is more in a

- venturimeter
- nozzle meter
- inclined venturimeter
- orifice meter

3. The loss of energy in orifice meter is more than in the case of venturimeter because of

- Sudden obstruction
- Turbulence
- pressure variation
- More friction

4. Orifices are used to measure

- rate of flow
- velocity
- pressure
- none of three mentioned here

5. In a standard orifice meter,

- the level edge is on the upstream
- the coefficient of discharge does not depend upon the location of taps
- the loss of head is less than that in a venturimeter
- the level angle is usually 30° to 45°

6. An orifice is called a large orifice if water head, is

- twice the diameter of the orifice
- thrice the diameter of the orifice
- four times the diameter of the orifice
- five times the diameter of the orifice

7. Two small orifices A and B of diameter 1 cm and 2 cm respectively, are placed on sides of a tank at depths of h_{1} and h_{2} below the open liquid surface. If discharges through A and B are equal, then ratio of h_{1} and h_{2} (assuming equal c_{d }values) will be

- 16 : 1
- 8 : 1
- 4 : 1
- 2 : 1

8. In a short cylindrical external mouthpiece, the vena-contracta occurs at a distance from the outlet of orifice equal to

- Diameter of the orifice
- One-fourth the diameter of the orifice
- One-third the diameter of the orifice
- Two-third the diameter of the orifice
- Two times the diameter of the orifice

9. Coefficient of discharge in terms of orifice is, actual discharge ‘a’ and ideal discharge ‘d’ is

- a/d
- d/a
- (a + d)/d
- (a – d)/d

10. The coefficient of discharge for an external mouthpiece depends upon

- Velocity of liquid
- Pressure of liquid
- Area of mouthpiece
- Length of mouthpiece

11. Which mouthpiece has the maximum coefficient of discharge?

- External mouthpiece
- Convergent divergent mouthpiece
- Internal mouthpiece
- None of the above

12. A convergent mouth piece has the maximum value of coefficient of discharge (C) is about

- 0.60
- 0.95
- 0.50
- 0.80

13. The average value of coefficient of velocity is

- 0.76
- 0.84
- 0.62
- 0.97

14. Consider the following devices:

- Orifice
- Borda’s mouthpiece running free
- Bell-mouthed orifice
- External mouthpiece

What is the correct sequence of these devices in decreasing magnitude of coefficient of discharge?

- ii, iii, i, iv
- iv, iii, i, ii
- iv, i, iii, ii
- ii, i, iii, iv

15. Mouthpiece has increased net head when compared to small orifice due to

- turbulence in the tube
- vena contracta occurred within the tube
- smaller length of the tube
- smooth boundary of the tube

16. A mouthpiece and an orifice, both of the same diameter ‘d’, are discharging under the same head ‘H’. The discharge through the mouthpiece will be

- the same as that of the orifice
- less than that of the orifice
- more than that of the orifice
- no relationship

17. At vena contracta, the area of the water jet is minimum and the velocity of emerging water is

- minimum
- average
- maximum
- zero

18. An orifice discharges under a head of 1.25m of water. A pitot tube kept at its centre line at the vena contracta indicates a head of 1.20 m of water. The coefficient of velocity of the orifice is

- 0.980
- 0.990
- 0.965
- 0.9565

19. A vertical cylindrical tank, 2 m diameter has, at the bottom, a 5 cm diameter, sharp-edged orifice, for which C_{d} = 0.6. Water enters the tank at a constant rate of 9 l/sec. At what depth above the orifice will the level in the tank become steady?

- 2.95 m
- 2.75 m
- 2.60 m
- 2.50 m

20. The ratio of velocity of flow at exit to theoretical velocity of jet corresponding to manometric head is known as

- Specific speed
- Flow ratio
- Speed ratio
- Hydraulic ratio

21. The coefficient of discharge, C_{d} in terms of C_{v} and C_{c} is given (Notations have their usual meaning)

- C
_{v}= C_{d}× C_{c} - C
_{c}= C_{d}× C_{v} - C
_{d}= C_{c}× C_{v} - C
_{d}= C_{c}– C_{v}

22. The height of water level in a tank above the centre of a circular hole 2.5 cm in diameter is 50m. The velocity of water flowing through the hole is (neglect friction between jet and wall)

- 25.85 m/sec
- 20.53 m/sec
- 40.40 m/sec
- 31.32 m/sec