A jet of water discharging from a 40 mm diameter orifice has a diameter of 32 mm at its vena contracta. The coefficient of contraction is

What is the co-efficient of contraction, if a fluid jet discharging from a 50 mm diameter orifice has a 40 mm diameter at its vena-contracta?

A

0.64

B

1.65

C

0.32

D

0.94

The fluid jet discharging from a 2" diameter orifice has a diameter of 1.75" at its vena-contracta. The co-efficient of contraction is

A

1.3

B

0.766

C

0.87

D

None of these

The theoretical velocity of jet at vena contracta is (where H = Head of water at vena contracta)

A

$$2{\text{gH}}$$

B

$${\text{H}}\sqrt {2{\text{g}}} $$

C

$$2{\text{g}}\sqrt {\text{H}} $$

D

$$\sqrt {2{\text{gH}}} $$

In an internal mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to height of the liquid above the vena contracta.

A

Less than

B

More than

C

Equal to

D

None of these

In an external mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to 0.89 times the height of the liquid, above the vena contracta.

A

Less than

B

More than

C

Equal to

D

None of these

In a short cylindrical external mouthpiece, the vena contracta occurs at a distance __________ the diameter of the orifice from the outlet of orifice.

A

Equal to

B

One-fourth

C

One-third

D

One-half

The discharge through a wholly drowned orifice is given by (where H₁ = Height of water (on the upstream side) above the top of the orifice, H₂ = Height of water (on the downstream side) above the bottom of the orifice and H = Difference between two water levels on either side of the orifice)

A

$${\text{Q}} = {{\text{C}}_{\text{d}}} \times {\text{b}}{{\text{H}}_1}\sqrt {2{\text{gh}}} $$

B

$${\text{Q}} = {{\text{C}}_{\text{d}}} \times {\text{b}}{{\text{H}}_2}\sqrt {2{\text{gh}}} $$

C

$${\text{Q}} = {{\text{C}}_{\text{d}}} \times {\text{b}}\left( {{{\text{H}}_2} - {{\text{H}}_1}} \right)\sqrt {2{\text{gh}}} $$

D

$${\text{Q}} = {{\text{C}}_{\text{d}}} \times {\text{bH}}\sqrt {2{\text{gh}}} $$

The discharge through a small rectangular orifice is given by (where C_d = Coefficient of discharge for the orifice, a = Cross-sectional area of the orifice, h = Height of the liquid above the centre of the orifice)

A

$${\text{Q}} = {{\text{C}}_{\text{d}}} \times {\text{a}} \times \sqrt {2{\text{gh}}} $$

B

$${\text{Q}} = \frac{2}{3}{{\text{C}}_{\text{d}}} \times {\text{a}} \times {\text{h}}$$

C

$${\text{Q}} = \frac{{{{\text{C}}_{\text{d}}} \times {\text{a}}}}{{\sqrt {2{\text{gh}}} }}$$

D

$${\text{Q}} = \frac{{3{{\text{C}}_{\text{d}}} \times {\text{a}}}}{{\sqrt {2{\text{h}}} }}$$

The discharge through a large rectangular orifice is given by (where H₁ = Height of the liquid above the top of the orifice, H₂ = Height of the liquid above the bottom of the orifice, b = Breadth of the orifice and C_d = Coefficient of discharge)

A

$${\text{Q}} = \frac{2}{3} \times {{\text{C}}_{\text{d}}} \times {\text{b}}\sqrt {2{\text{g}}} \left( {{{\text{H}}_2} - {{\text{H}}_1}} \right)$$

B

$${\text{Q}} = \frac{2}{3} \times {{\text{C}}_{\text{d}}} \times {\text{b}}\sqrt {2{\text{g}}} \left( {{\text{H}}_2^{\frac{1}{2}} - {\text{H}}_1^{\frac{1}{2}}} \right)$$

C

$${\text{Q}} = \frac{2}{3} \times {{\text{C}}_{\text{d}}} \times {\text{b}}\sqrt {2{\text{g}}} \left( {{\text{H}}_2^{\frac{3}{2}} - {\text{H}}_1^{\frac{3}{2}}} \right)$$

D

$${\text{Q}} = \frac{2}{3} \times {{\text{C}}_{\text{d}}} \times {\text{b}}\sqrt {2{\text{g}}} \left( {{\text{H}}_2^2 - {\text{H}}_1^2} \right)$$

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

A jet of water discharging from a 40 mm diameter orifice has a diameter of 32 mm at its vena contracta. The coefficient of contraction is

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