Final answer:
Fourier's law is used to express the relationship of rate of conductive heat flow proportional to the temperature gradient. Therefore, the correct answer is A) Fourier's law.
Step-by-step explanation:
The equation used to express the relationship of rate of conductive heat flow proportional to the temperature gradient is Fourier's law. According to Fourier's law, the rate of heat flow is directly proportional to the temperature difference and the cross-sectional area of the material, and inversely proportional to the thickness of the material. The equation can be written as:
Q = -kA(dT/dx)
where:
- Q is the rate of heat flow
- k is the thermal conductivity of the material
- A is the cross-sectional area
- dT/dx is the temperature gradient
The equation used to express the relationship of rate of conductive heat flow proportional to the temperature gradient is known as Fourier's law. According to Fourier's law, the heat conducted through a material is proportional to the negative gradient in the temperature and to the area, at right angles to that gradient, through which the heat is flowing.