What is the thermal conductivity of a perfect heat insulator ?
A. Zero
B. One
C. ∞
D. Between 0 and ∞
Month: March 2019
The value of Stefan-Boltzmann constant in SI unit is_________________?
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
A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2.K. The Biot number is ______________?
A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2.K. The Biot number is ______________?
A. 5.6
B. 0.025
C. 3.5
D. 0.0035
Air is best heated with steam in a heat exchanger of__________________?
Air is best heated with steam in a heat exchanger of__________________?
A. Plate type
B. Double pipe type with fin on steam side
C. Double pipe type with fin on air side
D. Shell and tube type
Which is the most suitable for the concentration of foamy & frothy liquors ?
Which is the most suitable for the concentration of foamy & frothy liquors ?
A. Agitated film evaporator
B. Long tube vertical evaporator
C. Open pan evaporator
D. None of these
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) ?
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
Boiling point elevation of an ideal solution_______________?
Boiling point elevation of an ideal solution_______________?
A. Increases rapidly with temperature rise
B. Decreases rapidly with temperature rise
C. In independent of pressure
D. Both B. and C.
The main function of baffles provided in a shell and tube heat exchanger is to______________?
The main function of baffles provided in a shell and tube heat exchanger is to______________?
A. Facilitate the cleaning of outer tube surface
B. Enhance turbulence
C. Hold the tubes in position
D. All A , B & C
Steam side heat transfer co-efficient in an evaporator is in the range of ______________ kcal/hr.m2°C?
Steam side heat transfer co-efficient in an evaporator is in the range of ______________ kcal/hr.m2°C?
A. 10-50
B. 100-500
C. 1000-1500
D. 5000-15000
The ratio of total radiating power to the absorptivity of the body depends upon the _____________ as per Kirchoff‟s law?
The ratio of total radiating power to the absorptivity of the body depends upon the _____________ as per Kirchoff‟s law?
A. Wavelength of radiation
B. Nature of the body
C. Temperature of the body
D. None of these