There metal walls of same cross-sectional area having thermal conductivity in the ratio 1 : 2 : 4 transfer heat at the rate of 15000 kcal/hr. For same thickness of wall, the temperature deop will be in the ratio

Heat Transfer Mcqs
BILAL KHATTAK0

A.1 ; 2 ; 4
B.4 ; 2 ; 1
C.1 :

E.1 ; 1 ; 1

Related Mcqs:

  1. The rate of heat loss through a furnace wall is 1000 kcal per hour when inside temperature is 1000?C and outside wall temperature is 500?C. What should be the wall thickness in case the thermal conductivity of wall material is 0.5 kcal/m-hr?C
  2. The face temperatures of a flat wall are 650?C and 450?C respectively and the thermal conductivity of wall material is 0.30 kcal/m-hr-?C. For a wall thickness of 20 cm, the rate of heat conduction per square meter of wall area will be
  3. The surface temperatures of a flat wall are 650?C and 450?C respectively and the thermal conductivity of the wall material is 0.30 kcal/m-hr-?C. The heat flux for a wall of 20 cm thickness will be
  4. The ratio of heat flow QA/QB from two walls of same thickness having thermal conductivity kA = 2 kB, for the same temperature difference will be
  5. A sphere of radius 40 cm is lagged to a radius of 50 cm. The temperatures of outer and inner surfaces are 66?C and 235?C respectively. Thermal conductivity of logging per cm thickness is 0.7 kcal/m-hr?C. The rate of heat leakage will be
  6. The rate of heat flow from a 50 mm thick wall of material having thermal conductivity of 40 W/m?C for a temperature difference of 10?C will be
  7. A dimensionless heat transfer coefficient which gives a measure of the ratio of the heat transfer rate to the rate at which heat would be conducted within the fluid under a temperature gradient is known as
  8. A wall has two layers A and B, each made of a different material. Both the layers have the same thickness. The thermal conductivity of material of A is twice that of B. Under the thermal equilibrium the temperature difference across the wall is 30?C. The temperature drops in layers A and B will be respectively
  9. A dimensionless number which is the ratio of mass heat flow rate to the heat flow rate by conduction under a unit temperature gradient and through a thickness L is known as
  10. In the temperature of air above a pond is 8?C thermal conductivity of ice is 0.005 C.G.S. units, latent heat of fusion of ice is 79.9 cal/gram the density of ice is 1 gm/cu.m, the time taken for the formation of ice layer of 1 cm thickness is

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