Dr. Byoung Hee You TECH 4392, MFGE 4392, and TECH 5392 Solutions: Homework#1 1. How does energy-band theory explain the difference among insulators, conductors, and semiconductors? Ans) There are three different materials based on the flow of electric current through these materials. The energy band gap explains how a material can be an insulator, conductor or semiconductor. Insulators have a large energy gap between the valence and conduction bands. It is difficult for electrons to jump the gap. Conductors have overlapping bands making the jump for electrons very easy and electricity is conducted with little required energy. Semiconductors have an energy gap but when energy is supplied to the material the electrons can be excited to across the band gap. 2. What is resistance? State the resistance formula. Ans) Resistance is the material property opposing to the current flow. It is a function of resistivity, area, length of the material, R = ρL/A.
has intentionally blurred sections.
Sign up to view the full version.