1. Conductors

  1. Conductors are materials that allow the easy flow of electric current.
  2. Their conductivity is due to the presence of free electrons.
  3. Examples include metals such as copper, aluminum, and silver.
  4. Conductors have very low resistivity (10⁻⁶ to 10⁻⁸ Ω·m).
  5. They are widely used in electrical wiring and electronic circuits.

2. Insulators

  1. Insulators are materials that resist the flow of electric current.
  2. Their atomic structure does not allow free movement of electrons.
  3. Examples include rubber, glass, and plastic.
  4. Insulators have very high resistivity (10⁸ to 10¹⁴ Ω·m).
  5. They are used for insulating cables and as protective coatings in electrical devices.

3. Semiconductors

  1. Semiconductors are materials that have intermediate conductivity between conductors and insulators.
  2. At low temperatures, they act as insulators, and at higher temperatures, their conductivity increases.
  3. Examples include silicon and germanium.
  4. Their resistivity lies between 10⁻³ and 10³ Ω·m.
  5. Semiconductors are the backbone of modern electronics, including diodes and transistors.

4. Difference Between Conductors, Insulators, and Semiconductors

  1. Conductors: High conductivity and low resistivity.
  2. Insulators: Low conductivity and high resistivity.
  3. Semiconductors: Conductivity depends on temperature and doping.

5. Band Theory of Solids

  1. The valence band is the highest energy band occupied by electrons in an atom.
  2. The conduction band is the next higher energy band where electrons can move freely.
  3. Conductors: The valence and conduction bands overlap, allowing free flow of electrons.
  4. Insulators: A large energy gap exists between the valence and conduction bands.
  5. Semiconductors: A small energy gap exists, making them conduct under certain conditions.

6. Applications of Semiconductors

  1. Diodes: Used for rectification, converting AC to DC.
  2. Transistors: Used as amplifiers and switches in electronic circuits.
  3. Solar cells: Convert sunlight into electrical energy using semiconductors.
  4. Integrated Circuits (ICs): Comprise millions of semiconductor components on a chip.
  5. LEDs: Emit light when current passes through a semiconductor material.

7. Importance in Modern Electronics

  1. Semiconductors form the foundation of microprocessors and computer chips.
  2. They are crucial in developing communication devices like smartphones and radios.
  3. Used in power electronics, controlling and converting electrical power efficiently.
  4. Semiconductors have revolutionized the fields of automation and robotics.

Category

Questions

  1. What defines a semiconductor?
  2. What is an example of a good semiconductor?
  3. Which of the following is an insulator?
  4. What property differentiates conductors from semiconductors?
  5. Which material is commonly used in the manufacturing of diodes?
  6. What happens to the resistance of a semiconductor as temperature increases?
  7. What is the bandgap in a semiconductor?
  8. What is the role of doping in semiconductors?
  9. What type of material is glass?
  10. Which of the following is a good conductor of electricity?
  11. What determines whether a material is a conductor, insulator, or semiconductor?
  12. What is a p-type semiconductor?
  13. Which of these is an intrinsic semiconductor?
  14. Which material is not a semiconductor?
  15. What is the typical resistivity of conductors compared to semiconductors?
  16. What happens to the conductivity of a semiconductor when impurities are added?
  17. Which property makes insulators different from conductors?
  18. What is the main advantage of semiconductors over conductors in electronics?
  19. What is the bandgap of a typical semiconductor like silicon?
  20. What are the majority charge carriers in an n-type semiconductor?
  21. Which material is typically used in solar cells?
  22. What happens to the energy gap in a semiconductor at absolute zero?
  23. Which of the following materials is an example of a good insulator?
  24. What type of bond is present in semiconductors?
  25. Which of the following increases conductivity in a semiconductor?
  26. What type of semiconductor is formed by doping silicon with phosphorus?
  27. Why do insulators have high resistance?
  28. What type of material is germanium?
  29. What determines the movement of electrons in a conductor?
  30. What is the unit of resistivity?
  31. What happens to the conductivity of an intrinsic semiconductor when temperature increases?
  32. What is the process of adding impurities to a semiconductor called?
  33. Which of the following is a compound semiconductor?
  34. What are the majority charge carriers in a p-type semiconductor?
  35. What is the resistivity of an ideal conductor?
  36. Which phenomenon allows semiconductors to be used in diodes and transistors?
  37. Which of the following is a property of conductors?
  38. What is an example of a material with very high resistivity?
  39. What is the temperature coefficient of resistance in a typical conductor?