Thermal diffusivity of a substance is

A Directly proportional to the thermal conductivity
B Inversely proportional to density of substance
C Inversely proportional to specific heat
D All of the above

Correct Answer: All of the above

The thermal diffusivity of a substance or material is the thermal conductivity divided by the density and specific heat capacity at constant pressure and is a measure the rate of transfer of heat of a substance or material from the hot side to the cold side.
Bissoy MCQ
#Mechanical Engineering #Heat And Mass Transfer

Related Questions

Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity)
A $$\frac{1}{{\text{k}}}$$
B k
C k2
D $$\frac{1}{{{{\text{k}}^2}}}$$
The ratio of momentum diffusivity to thermal diffusivity is the __________ number.
A Prandtl
B Nusselt
C Stanton
D Grashoff
If mass diffusivity in a mixture is equal to the thermal diffusivity, then the Lewis number is
A 0
B 1
C > 1
If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the
A Pressure
B Temperature
C Both A & B
D Neither A nor B
The unit of thermal diffusivity is
A m2/hr-K
B kcal/m2-hr
C m2/hr
D m/hr-K
Thermal diffusivity is a
A Function of temperature
B Physical property of a substance
C Dimensionless parameter
D All of these
Thermal diffusivity is
A A dimensionless parameter
B Function of temperature
C Used as mathematical model
D A physical property of the material
Unit of thermal diffusivity is
A m2/hr
B m2/hr °C
C kcal/m2 hr
D kcal/m hr °C
The highest thermal diffusivity is of
A Iron
B Lead
C Concrete
D Wood
The lowest thermal diffusivity is of
A Iron
B Lead
C Aluminium
D Rubber

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