Thermal diffusivity of a substance is ____________________? - PakMcqs

Related Mcqs:

1. Thermal diffusivity of a substance is __________________?

   A. directly proportional to thermal con¬ductivity B. inversely proportional to density of substance C. inversely proportional to specific heat D. all of the above E. none of the above...

2. Thermal diffusivity is ____________________?

   A. a dimensionless parameter B. function of temperature C. used as mathematical model D. a physical property of the material E. useful in case of heat transfer by radiation...

3. Unit of thermal diffusivity is_________________?

   A. m2/hr B. m2/hr°C C. kcal/m2 hr D. kcal/m.hr°C E. kcal/m2 hr°C...

4. Thermal conductivity of water in general with rise in temperature ____________________?

   A. increases B. decreases C. remains constant D. may increase or decrease depending on temperature E. none of the above...

5. Unit of thermal conductivity in M.K.S. units is ___________________?

   A. kcal/kg m2 °C B. kcal-m/hr m2 °C C. kcal/hr m2 °C D. kcal-m/hr °C E. kcal-m/m2 °C...

6. Thermal conductivity of solid metals with rise in temperature normally___________________?

   A. increases B. decreases C. remains constant D. may increase or decrease depending on temperature E. unpredictable...

7. Thermal conductivity of air at room temperature in kcal/m hr °C is of the order of__________________?

   A. 0.002 B. 0.02 C. 0.01 D. 0.1 E. 0.5...

8. Which of the following is expected to have highest thermal conductivity_______________?

   A. steam B. solid ice C. melting ice D. water E. boiling water...

9. Thermal conductivity of a material may be defined as the________________?

   A. quantity of heat flowing in one second through one cm cube of material when opposite faces ^re maintained at a temperature difference of 1°C B. quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C...

10. The thermal diffusivities for gases are generally_____________________?

    A. more than those for liquids B. less than those for liquids C. more than those for solids D. dependent on the viscosity E. same as for the liquids...