Question

An orifice meter is installed in a pipe of diameter \(20\,\text{cm}\). If the discharge coefficient is assumed constant, the flow rate is proportional to

• A. Pressure difference
• B. Square root of pressure difference
• C. Velocity
• D. Pipe diameter only

Hint:

For an orifice meter, \[ \boxed{ Q\propto\sqrt{\Delta P} } \] when the discharge coefficient remains constant.

Answer 1

The Correct Option is B

Step 1: Use the discharge equation of an orifice meter. The discharge through an orifice meter is \[ Q=C_dA\sqrt{\frac{2\Delta P}{\rho}}. \] Here, \(C_d\), \(A\), and \(\rho\) are constant.

Step 2: Determine the proportionality. Therefore, \[ Q\propto\sqrt{\Delta P}. \] Hence, \[ \boxed{\text{Flow rate is proportional to the square root of pressure difference.}} \] Therefore, \[ \boxed{(B)} \] is the correct answer.