Maximum permissible air velocity in pipelines is about ______________ metre/second ?

Related Mcqs:

1. A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness ______________ metre?

   A. 0.01
   B. 0.1
   C. 0.25
   D. 0.5

2. Maximum permissible sulphur content in steel is ______________ percent ?

   A. 0.015
   B. 0.055
   C. 0.505
   D. 0.805

3. ______________ joint is usually used for joining cast iron pipes mostly used for temporary pipelines, where it may be necessary to dismantle & reassemble the pipeline very frequently ?

   A. Collar
   B. Flanged
   C. Bell and Spigot
   D. Expansion

4. As per international norms, the maximum permissible value of noise level in the industrial environment is _____________ decibels as measured at a distance of 1.5 meters from the source of noise?

   A. 110
   B. 85
   C. 60
   D. 45

5. Water hammer is caused in steam carrying pipelines, because of ______________________?

   A. Partial condensation of steam
   B. Vibration of the pipeline
   C. High degree of superheat of steam
   D. Its exposure to torrential rain

6. Pipelines carrying various utilities in chemical industries are identified by their colour codes. The color of pipeline carrying steam is__________________?

   A. Black
   B. Silver grey
   C. Green
   D. Yellow

7. Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode________________?

   A. Occurs higher in the electro-chemical series of metals
   B. Is exemplified by magnesium plate
   C. Is much cheaper than the cathodic base material to be guarded against corrosion
   D. All A, B. & C.

8. In Newton’s law of viscosity, which states that the shear stress is proportional to the _____________ Co-efficient of viscosity is called dynamic or absolute viscosity(where, V = velocity, Vg = velocity gradient) ?

   A. V2
   B. 1/V2
   C. 1/Vg
   D. Vg

9. Rain drops falling through atmospheric air attain limited terminal velocity, because of ____________________?

   A. Upward thrust due to air
   B. Viscous force exerted by air
   C. Surface tension effects of water
   D. Force of gravity

10. The most economical channel section for the fluid flow is the one for which the discharge is maximum for a given cross-sectional area. Vertical velocity distribution in an open channel for laminar flow can be assumed to be_______________?

    A. Parabolic
    B. Hyperbolic
    C. Straight line
    D. None of these