A 2″ gate valve fitted in a pipe is replaced by a similar globe valve. Pressure drop in gate valve was Δp. For the same discharge, the pressure drop across globe valve is__________________?

Related Mcqs:

1. For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is___________________?

   A. More
   B. Less
   C. Equal
   D. Either A. or B.; depends on the viscosity of the fluid

2. The pressure drop per unit length of pipe incurred by a fluid ‘X’ flowing through pipe is Δp. If another fluid ‘Y’ having both the specific gravity & density just double of that of fluid ‘X’, flows through the same pipe at the same flow rate/average velocity, then the pressure drop in this case will be__________________?

   A. Δp
   B. 2Δp
   C. Δp2
   D. Δp/2

3. Applying a pressure drop across a capillary results in a volumetric flow rate ‘Q’ under laminar flow conditions. The flow rate for the same pressure drop, in a capillary of the same length but half the radius is____________________?

   A. Q/2
   B. Q/4
   C. Q/8
   D. Q/16

4. A mercury (specific gravity = 13.6) manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be _______________ cms?

   A. 17
   B. 42
   C. 84
   D. 1.8

5. What is the shear rate at the pipe wall, in case of laminar flow of Newtonian fluids in a pipe of diameter ‘D’ & length ‘L’ incurring a pressure drop ‘Δp’ with average velocity ‘Vavg’ ?

   A. D Δp/8L
   B. D Δp/4L
   C. 8 Vavg/D
   D. 4 Vavg/D

6. For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) ?

   A. μ
   B. 1/μ
   C. √μ
   D. 1/√μ

7. Vena-contracta pressure tapping is at a distance _______________ from the position of an orificemeter fitted in a pipe of internal diameter ‘d’ ?

   A. d
   B. 0.5 d
   C. 2d
   D. 4d

8. A globe valve is the most suitable for applications, in which____________________?

   A. Fluid flow control is required
   B. Fluid contains dispersed solid particles
   C. Valve is required to be either fully open or fully closed
   D. One way flow is required

9. 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__________________?

   A. 0.42
   B. 0.62
   C. 0.82
   D. 0.98

10. A gas (density = 1.5 kg/m3, viscosity = 2 × 10‒5 kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5 kg/m3and viscosity of 3 × 10‒5kg/m.s flowing at 3 m/s will be________________?

    A. 8400 Pa/m
    B. 12600 Pa/m
    C. 18900 Pa/m
    D. 16800 Pa/m