Fins are used to increase heat transfer rate from a surface by1.increa...
Explanation:
Fins are widely used in various engineering applications for enhancing the heat transfer rate from a surface. The primary function of fins is to increase the effective surface area of a heat transfer surface so that more heat can be transferred from the surface. However, fins can also affect other parameters that affect heat transfer rate. Let's discuss each of the given options one by one:
1. Increasing the Temperature Difference:
Increasing the temperature difference between the surface and the surrounding fluid can enhance the heat transfer rate. However, fins do not directly affect the temperature difference between the surface and the fluid. Therefore, option 1 is incorrect.
2. Increasing the Effective Surface Area:
Fins are designed to increase the effective surface area of a heat transfer surface. By increasing the surface area, the contact area between the surface and the fluid increases, which enhances the heat transfer rate. Therefore, option 2 is correct.
3. Increasing the Convective Heat Transfer Coefficient:
Convective heat transfer coefficient is a measure of the efficiency of heat transfer between a surface and a fluid. Fins can enhance the convective heat transfer coefficient by promoting fluid flow and turbulence around the surface. However, fins do not directly affect the convective heat transfer coefficient. Therefore, option 3 is incorrect.
4. Decreasing the Thermal Conductivity:
Thermal conductivity is a measure of the ability of a material to conduct heat. Fins do not affect the thermal conductivity of the surface material. Therefore, option 4 is incorrect.
Conclusion:
From the above explanation, it is clear that option 2 is correct, and options 1, 3, and 4 are incorrect. Therefore, the correct answer is option C, i.e., 2 only.
Fins are used to increase heat transfer rate from a surface by1.increa...
Pls exp