Basic Electronics Paper 2, WASSCE (PC 2ND), 2021

Question 1

 

  1.  List four types of electron emission.
  2.  Draw a labelled diagram of a cathode ray tube.
           

 

 The expected responses were:
Types of electron emission

  • Thermionic emission
  • Photoemission
  • Secondary emission
  • Field emission / cold cathode

 (b)       Labelled diagram of a cathode ray tube  

 

According to the Chief Examiner, while majority of the candidates that attempted this question were able to list the different types of electron emission as required in the first task, only a few of them could convincingly respond to the second which demanded more from the them.