The height of water on upstream and downstream side of a submerged weir of 4 m length are 24 cm and 13 cm. If Cd for free and drowned portions are .62 and .78 respectively, find the discharge over the weir.

The height of water on upstream and downstream side of a submerged weir of 4 m length are 23.5 cm and 14 cm. If Cd for free and drowned portions are .61 and .75 respectively, find the discharge over the weir.

A

m3/s

B

1.35 m3/s

C

3.2 m3/s

D

.55 m3/s

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

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

In a broad-crested weir, the discharge is maximum if the head of water on the downstream side of weir is __________ the head of water on the upstream side of weir.

A

Equal to

B

One-third

C

Two-third

D

Three-fourth

The discharge over a rectangular weir, considering the velocity of approach, is (where H₁ = H + H_a)
(H₁ = Total height of water above the weir, H = Height of water over the crest of the weir and H_a = Height of water due to velocity of approach)

A

$$\frac{2}{3}{{\text{C}}_{\text{d}}} \times {\text{L}}\sqrt {2{\text{g}}} \left$$

B

$$\frac{2}{3}{{\text{C}}_{\text{d}}} \times {\text{L}}\sqrt {2{\text{g}}} \left$$

C

$$\frac{2}{3}{{\text{C}}_{\text{d}}} \times {\text{L}}\sqrt {2{\text{g}}} \left$$

D

$$\frac{2}{3}{{\text{C}}_{\text{d}}} \times {\text{L}}\sqrt {2{\text{g}}} \left$$

For discharge over ogee weir discharge is directly proportional to length but for discharge over narrow crested weir it is inversely proportional to length.

A

True

B

False

A man can cross a downstream river by steamer in 40 minutes and same by boat in 1 hour. If the time of crossing Upstream by streamer is 50% more than downstream time by steamer and the time required by boat to cross same river by boat in upstream is 50% more than time required by in downstream. What is the time taken for the man to cross the river downstream by steamer and then return to same place by boat half the way and by steamer the rest of the way?

A

85 minutes

B

115 minutes

C

120 minutes

D

125 minutes

E

None of these

A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.

A

Equal to

B

Less than

C

More than

D

None of these

A weir is said to be broad crested weir, if the width of the crest of the weir is ________ half the height of water above the weir crest.

A

Equal to

B

Less than

C

More than

D

None of these

When the water level on the downstream side of a weir is above the top surface of a weir, the weir is known as

A

Narrow-crested weir

B

Broad-crested weir

C

Ogee weir

D

Submerged weir

Find the discharge through totally drowned orifice of width 2.3 m if the difference of water levels on both side of the orifice be 40 cm. The height of water from to and bottom of the orifice are 2.6 m and 2.75 m respectively.

A

.56 m3/s

B

.64 m3/s

C

.75 m3/s

D

.55 m3/s

The height of water on upstream and downstream side of a submerged weir of 4 m length are 24 cm and 13 cm. If Cd for free and drowned portions are .62 and .78 respectively, find the discharge over the weir.

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