Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about

Co-efficient of discharge (C_d) is defined as actual discharge/theoretical discharge and is equal to C_c . C_v; where C_c = Co-efficient of contraction and C_v = co-efficient of velocity. C_d of an orifice is usually about

A

0.42

B

0.62

C

0.82

D

0.98

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

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

The discharge through a small rectangular orifice is given by (where Cd = 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

Q = Cd × a × 2gh

B

Q = (2/3). Cd × a × h

C

Q = (Cd × a)/√(2gh)

D

Q = (3Cd × a)/√(2h)

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

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

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

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

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

A fluid flows through an orifice of an area 0.4 m2 with an actual discharge of 400 l/s. If the theoretical velocity of flow through the orifice is 2 m/s, what is the coefficient of discharge?

A

0.71

B

0.68

C

0.50

D

0.56

An orifice meter, having an orifice of diameter ‘d’ is fitted in a pipe of diameter D. For this orifice meter, what is the coefficient of discharge Cd?

A

A function of Reynolds number only

B

A function of d/D only

C

A function of d/D and Reynolds number

D

Independent of d/D and Reynolds number

Two centrifugal pumps P and R are available for use in a pipe flow system and their head-discharge characteristics are as follows. Pump P Pump R Discharge (cumecs) Head (m) Discharge (cumecs) Head (m) 0 40 0 45 0.12 35 0.14 40 0.2 28 0.24 35 0.3 18 0.3 28 The following statements (S1, S2, and S3) pertain to the head and discharge values during actual operation. Neglect losses in the system. Which of the following statements are correct? S1: When the two pumps P and R are connected in parallel, the discharge is 0.36 cumecs corresponding to a head of 35 m. S2: When the two pumps P and R are connected in parallel, the discharge is 0.36 cumecs corresponding to a head of 70 m. S3: When the two pumps P and R are connected in series, the discharge is 0.3 cumecs corresponding to a head of 46 m.

A

S2 only

B

S1 and S3

C

S1 and S2

D

S2 and S3

Regarding the Indian economy, which of the following reflect, unprecedented suspension of economic activity in the first quarter of this fiscal (April - June) due to the Covid pandemic (a) Contraction of around 50.3% in the construction sector (b) Contraction of around 39.3% in the manufacturing sector (c) Contraction of around 10% in the Agri, forestry and fishing sector (d) Contraction of around 5% in the Trade, hotels, transport sector

A

(a) and (b) only

B

(a) and (c) only

C

(b) and (c) only

D

(b) and (d) only

E

Answer not known

Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about

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