A. 0.1
B. 0.3
C. 0.7
D. 1.7
E. 10.5
Related Mcqs:
- 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 - Thermal conductivity of air with rise in temperature__________________?
A. increases
B. decreases
C. remains constant
D. may increase or decrease depending on temperature
E. none of the above - Which of the following property of air does not increase with rise in temperature ________________?
A. thermal conductivity
B. thermal diffusivity
C. density
D. dynamic viscosity
E. kuiematic viscosity - Which of the following has least value of conductivity_________________?
A. glass
B. water
C. plastic
D. rubber
E. air - Which of the following has maximum value of thermal conductivity________________?
A. aluminium
B. steel
C. brass
D. copper
E. lead - The value of the wavelength for maximum emissive power is given by ___________________?
A. Wien’s law
B. Planck’s law
C. Stefan’s law
D. Fourier’s law
E. Kirchhoff’s law - 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 - Which of the following is expected to have highest thermal conductivity_______________?
A. steam
B. solid ice
C. melting ice
D. water
E. boiling water - According to Kirchoff’s law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a _________________?
A. grey body
B. brilliant white polished body
C. red hot body
D. black body
E. none of the above - Depending on the radiating properties, a body will be opaque when _________________?
A. p = 0, x = 0 and a = 1
B. p=l,x = 0anda = 0
C. p = 0, x = 1 and a = 0
D. x – 0, a + p = 1
E. a=0,x + p= 1.where a = absorptivity, p = reflectivity, X = transmissivity
