Introductory Electronics Flashcards
1
Q
What are the key differences between metals, semiconductors, and insulators?
A
- Metals: Have free electrons that conduct electricity well. They have high electrical conductivity and low band gap (typically 0 eV).
- Semiconductors: Have a moderate band gap (e.g., 0.7 to 3 eV). Their conductivity lies between metals and insulators. Conductivity can be altered by doping.
- Insulators: Have a large band gap (greater than 3 eV), which prevents electron flow, resulting in very low electrical conductivity.
2
Q
What is the difference between intrinsic and extrinsic semiconductors?
A
- Intrinsic Semiconductors: Pure semiconductors with no added impurities (e.g., silicon, germanium). Their electrical properties are due to the properties of the semiconductor material itself.
- Extrinsic Semiconductors: Semiconductors that have been doped with impurities to improve their electrical conductivity. They are classified into n-type and p-type semiconductors.
3
Q
How are semiconductors and diodes used in rectification and transistors in amplification?
A
- Diodes: Used in rectification to convert alternating current (AC) to direct current (DC). They allow current to flow in one direction only.
- Transistors: Used in amplification to increase the strength of electrical signals. They can act as switches or amplifiers.
4
Q
What are n-type and p-type semiconductors?
A
- N-Type Semiconductors: Doped with elements that provide extra electrons (e.g., phosphorus in silicon), resulting in an excess of negative charge carriers (electrons).
- P-Type Semiconductors: Doped with elements that create “holes” (missing electrons) in the semiconductor lattice, resulting in an excess of positive charge carriers (holes).
5
Q
What are the basic principles of diodes and transistors?
A
- Diodes: Have two terminals (anode and cathode) and allow current to flow only in one direction. They are used for rectification and signal demodulation.
- Transistors: Have three terminals (emitter, base, and collector). They can amplify electrical signals and switch electronic signals on and off. They are classified into bipolar junction transistors (BJTs) and field-effect transistors (FETs).