The Stefan-Boltzmann constant depends on the_________________?

Related Mcqs:

1. The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m2. The approximate surface temperature (K) is (Stefan-Boltzmann constant = 5.67 × 10-8 W/m2.K4) ?

   A. 1000
   B. 727
   C. 800
   D. 1200

2. The value of Stefan-Boltzmann constant in SI unit is_________________?

   A. 5.6697 × 10-8W/m2.°K4
   B. 0.1714 × 10-8W/m2.°K4
   C. 5.6697 × 10-8kcal/m2. °K4
   D. 0.1714 × 10-8kcal/m2. °K4

3. Stefan-Boltzmann law applies to _____________ body?

   A. Black
   B. White
   C. Grey
   D. Any colour

4. Stefan-Boltzmann law which describes the radiation heat transfer states that, it is proportional to (where, t = temperature in °C T = absolute temperature in ° K) ?

   A. t4
   B. T4
   C. 1/t4
   D. 1/T4

5. Stefan’s block body radiation law can also be derived from ______________ law?

   A. Kirchoff’s
   B. Planck’s
   C. Fourier’s
   D. None of these

6. The actual temperature drop across the heating surface in an evaporator depends on the_________________?

   A. Feed
   B. Depth of liquid over heating surface
   C. Pressure difference between steam chest and vapour space
   D. All A., B. and C.

7. Fluid motion in the natural convection heat transfer between a solid surface and a fluid in contact with it, results from the_________________?

   A. Existence of thermal boundary layer
   B. Temperature gradient produced due to density difference
   C. Buoyancy of the bubbles produced at active nucleation site
   D. None of these

8. LMTD can’t be used as such without a correction factor for the_________________?

   A. Multipass heat exchanger
   B. Baffled heat exchanger
   C. Condensation of mixed vapour in a condenser
   D. All A. B. and C.

9. In a gas-liquid shell and tube heat exchanger, the_________________?

   A. Presence of a non-condensable gas decreases the condensing film co-efficient
   B. Gases under high pressure are routed through the tube side, because high pressure gases are
   corrosive in nature
   C. Gases to be heated/cooled is normally routed through the shell side, because the corrosion
   caused by the cooling water or steam condensate remain localised to the tubes
   D. All A, B. & C.

10. Shell side pressure drop in a shell and tube heat exchanger does not depend upon the_________________?

    A. Baffle spacing & shell diameter
    B. Tube diameter & pitch
    C. Viscosity, density & mass velocity of shell side fluid
    D. None of these