In steady-state heat conduction O A. the temperature at each position along the specimen rises slowly over time. O B. the thermal conductivity of the specimen decreases. ° C. the temperature gradient along the specimen is constant. D. changing the flowrate of cooling water against the cold side does not affect its temperature.

Respuesta :

Answer: Option (C) is the correct answer.

Explanation:

For heat conduction (Q), the general form is as follows.

             [tex]\frac{d}{dx}(k\frac{dT}{dx}) + q = \rho C_{p}\frac{dT}{dZ}[/tex]

where,         q = heat generation

                [tex]\rho[/tex] = density

                  [tex]C_{p}[/tex] = specific heat

                    Z = time

                   k = thermal conductivity

                   x = spatial direction (positional)

When k = constant

    No heat is generated hence, q = 0

    steady state conduction [tex]\frac{dT}{dx}[/tex] = 0

Hence,  [tex]k \frac{d^{2}T}{dx^{2}}[/tex] + 0 = [tex]\rho C_{p} \times 0[/tex]

               [tex]k \frac{d^{2}T}{dx^{2}}[/tex] = 0

                     [tex]\frac{d^{2}T}{dx^{2}}[/tex] = 0

On integrating both sides we get the following.

          [tex]\frac{dT}{dx} = C_{1}[/tex] = constant

Therefore, the temperature gradient along the specimen remains constant.

Hence, we can conclude that the statement in steady-state heat conduction  the temperature gradient along the specimen is constant, is true.