Question

Which of the following statements are correct regarding the orifices and weirs? A. In orifice, the coefficient of discharge is product of coefficient of velocity and contraction B. Vena contracta is term used in rectangular weir C. The sheet of water flows over a weir is called as nappe D. Cipolletti is a type of orifice E. The V type of notch is used for low discharge in furrows Choose the correct answer from the options given below:

• A. A, B and C Only
• B. A, C and E Only
• C. B, D and E Only
• D. B, C and D Only

Hint:

Important formulas and facts: \[ \boxed{ C_d = C_c \times C_v } \] \[ \boxed{ \text{Water sheet over weir} = \text{Nappe} } \] \[ \boxed{ \text{V-notch} \Rightarrow \text{Small discharge measurement} } \]

Answer 1

The Correct Option is B

Concept: Orifices, notches, and weirs are hydraulic measuring devices used for discharge measurement. Key concepts:
• Coefficients of flow
• Vena contracta
• Nappe formation
• Types of notches and weirs

Step 1: Checking Statement A. Coefficient of discharge is: \[ C_d = C_c \times C_v \] where:
• \(C_c\) = coefficient of contraction
• \(C_v\) = coefficient of velocity Therefore: \[ \boxed{ \text{Statement A is correct} } \]

Step 2: Checking Statement B. Vena contracta is associated with:
• Orifice flow
• Jet contraction It is not specifically a rectangular weir term. Hence: \[ \boxed{ \text{Statement B is incorrect} } \]

Step 3: Checking Statement C. The water sheet flowing over a weir is called: \[ \boxed{ \text{Nappe} } \] Thus: \[ \boxed{ \text{Statement C is correct} } \]

Step 4: Checking Statement D. Cipolletti is:
• A trapezoidal weir
• Not an orifice Hence: \[ \boxed{ \text{Statement D is incorrect} } \]

Step 5: Checking Statement E. V-notch or triangular notch is highly suitable for:
• Small discharge measurement
• Furrow irrigation applications Therefore: \[ \boxed{ \text{Statement E is correct} } \]

Step 6: Writing correct combination. Correct statements are: \[ \boxed{ A,\ C,\ E } \]

Step 7: Checking options carefully. Option (A): Contains incorrect statement B. \[ \boxed{ \text{Option (A) is incorrect} } \] Option (B): Correct combination. \[ \boxed{ \text{Option (B) is correct} } \] Option (C): Contains incorrect statements. \[ \boxed{ \text{Option (C) is incorrect} } \] Option (D): Contains incorrect statement D. \[ \boxed{ \text{Option (D) is incorrect} } \] Final Conclusion: Correct statements are: \[ \boxed{ A,\ C,\ E \text{ Only} } \] Hence the correct answer is: \[ \boxed{ (B) } \]