Topic: Electromagnetics
Which of the following has the highest skin depth?
- A. Aluminium
- B. Gold
- C. Sliver
- D. Copper
Answer: A. Aluminium
Explanation: Skin depth $\delta$ is inversely proportional to the square root of conductivity ($\delta \propto 1/\sqrt{\sigma}$). Among the given options, Aluminium has the lowest electrical conductivity ($\sim 3.5 \times 10^7$ S/m), which results in the highest skin depth.