Question

Which of the following options are true regarding thermal conductivity?

• A. The reciprocal of thermal conductivity is thermal resistivity.
• B. The greater the thermal conductivity, the greater the heat flow.
• C. The greater the thermal conductivity, the less the heat flow.
• D. The SI unit of thermal conductivity is $J{M}^{-1}{S}^{-1}{K}^{-1}$.

Answer 1

Answer: (A), (B), (D)

The correct options are
A

The reciprocal of thermal conductivity is thermal resistivity.

B

The greater the thermal conductivity, the greater the heat flow.

D

The SI unit of thermal conductivity is $J{M}^{-1}{S}^{-1}{K}^{-1}$.

Thermal conductivity is the property of a material to conduct heat.

Formula for Thermal conductivity is

$Q=KA\left(\frac{{\theta }_1-{\theta }_2}{x}\right)t\Rightarrow K=\frac{Qx}{A({\theta }_1-{\theta }_2)t}$
Where, K= Coefficient of thermal conductivity
Q= Amount of heat flowing normally through the faces.
$({\theta }_1-{\theta }_2)$= Temperature difference
t= time of flow
A= Area of the face

Thermal resistivity is the ability of a material to resist the flow of heat. Thermal resistivity is the reciprocal of thermal conductivity.

$Thermalresistivity=\frac{1}{Thermalconductivity}$

The greater the thermal conductivity, the greater the heat flow.