Boiler tube size is specified by its thickness and _____________________ diameter ?

Related Mcqs:

1. Water-tube boiler is the one, in which _____________________?

   A. Water passes through tubes and flue gases around it
   B. Tube carrying hot flue gases are immersed in a pool of water
   C. Tubes are placed in vertical position
   D. None of these
   Answer: Option A

2. Which of the following is a boiler accessory i.e., not a boiler mounting ?

   A. Blow off cock
   B. Feed check valve
   C. Feed water pump
   D. Stop valve

3. The amount of water evaporated in kg per kg of fuel burnt in a boiler is called the ______________ of a boiler ?

   A. Evaporative capacity
   B. Evaporation efficiency
   C. Thermal efficiency
   D. Steam load

4. The delivery pressure of boiler feed water pump compared to the boiler steam pressure is___________________?

   A. Same
   B. Slightly less
   C. Slightly more
   D. Much more

5. The most prominent single cause of corrosion in boiler-tubes, drums, economisers and steam superheaters in a thermal power plant boiler is the_______________?

   A. Water alkalinity & leakage
   B. Hydrazine addition during feed water treatment
   C. Release of non-condensable gas from water in the boiler
   D. Scale formation

6. In case of water (Prandtl number ≈ 6) flowing over a flat plate heated over the entire length, the thermal boundary layer thickness as compared to hydrodynamic boundary layer thickness is ?

   A. Less
   B. More
   C. Equal
   D. Unpredictable

7. 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

8. The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) ?

   A. x1.5
   B. x0.8
   C. x-1.5
   D. x-0.8

9. A fire tube boiler is limited to a maximum steam pressure of about ______________ kg/cm2 ?

   A. 6
   B. 18
   C. 38
   D. 52

10. The most important function of a washer is to provide bearing area and washers are normally specified by their hole diameters. The diameter of washer as compared to the nut is__________________?

    A. More
    B. Less
    C. Same
    D. More but less than the diameter of bolt