Test: Fluid Dynamics & Flow Through Pipes - 1 - Mechanical Engineering MCQ

Which one of the following statements is correct? While using boundarylayer equations, Bernoulli’s equation 

Assertion (A): After the fluid has re-established its flow pattern down stream of an orifice plate, it will return to same pressure that it had upstream of the orifice plate. 
Reason (R): Bernoulli’s equation when applied between two points having the same elevation and same velocity gives the same pressure at these points.

A tank containing water has two orifices of the same size at depths of 40 cm and 90 cm below the free surface of water. The ratio of discharges through these orifices is: 

The instrument preferred in the measurement of highly fluctuating velocities in air flow is:  

If a calibration chart is prepared for a hot-wire anemometer formeasuring the mean velocities, the highest level of accuracy can be:  

Which one of the following is measured by a Rotameter? 

In a rotameter as the flow rate increase, the float  

A glass tube with a 90° bend is open at both the ends. It is inserted into a flowing stream of oil, S = 0.90, so that one opening is directed up stream and the other is directed upward. Oil inside the tube is 50mm higher than the surface of flowing oil. The velocity measured by the tube is, nearly,  

The speed of the air emerging from the blades of a running table fan is intended to be measured as a function of time. The point of measurement is very close to the blade and the time period of the speed fluctuation is four times the time taken by the blade to complete onerevolution. The appropriate method of measurement would involve the use of  

Which one of the statements is correct for a forced vortex?  

For a real fluid moving with uniform velocity, the pressure 

In a pipe flow, the head lost due to friction is 6 m. If the power transmitted through the pipe has to be the maximum then the total head at the inlet of the pipe will have to be maintained at  

Assertion (A): Energy grade line lies above the hydraulic grade line andis always parallel to it.  
Reason (R): The vertical difference between energy grade line andhydraulic grade line is equal to the velocity head.

Which phenomenon will occur when the value at the discharge end of apipe connected to a reservoir is suddenly closed? 

Water hammer in pipe lines takes place when  

Assertion (A): The power transmitted through a pipe is maximum when the loss of head due to friction is equal to one-third of total head at theinlet.  
Reason (R): Velocity is maximum when the friction loss is one-third ofthe total head at the inlet.

Which one of the following statements is appropriate for the free surface, the hydraulic gradient line and energy gradient line in anopen channel flow?