Which of the following statements about thermionic emission is NOT correct?

Which of the following statements about thermionic emission is NOT correct?

  1. Thermionic emission is a process in which electrons are emitted from a metal surface due to the thermal energy of the metal.
  2. Thermionic emission is a quantum mechanical process.
  3. Thermionic emission is used in vacuum tubes and electron guns.
  4. Thermionic emission is a type of photoelectric emission. ✓

Explanation

This physics concept involves analyzing the given values and applying relevant formulas. Work through the problem step by step using known equations and constants.

Identify what quantity needs to be found and which formula connects the given information to the answer. Substitute the values carefully, paying attention to units.

Check that your calculated answer matches one of the options provided. Understanding the underlying principle helps verify the solution makes physical sense.