waecE-LEARNING
Electronics Paper 2, Nov/Dec. 2012  
Questions: 1 2 3 4 5 6 7 8 9 10 Main
General Comments
Weakness/Remedies
Strength















Question 1
  • Question 1
    (a) State the function of the following in a cathode ray tube:
               (i)        electron gun;
               (ii)       X-plates;
               (Hi)     Y-plates;
               (iv)      fluorescent screen.
    (b) State two applications of the cathode ray tube.

         

_____________________________________________________________________________________________________
OBSERVATION

TThe expected answers were:
      (a)       (i)        Electron gun - emits high velocity beam of electrons
                 (ij)        X-plates - causes the horizontal deflection of the electron beam
                  (iii)       Y-plates - causes the vertical deflection of the electron beam
                  (iv)      Flourescent screen - emits visible lightwhen struck by the
electron beam
      (b)       - Television                - Picture display
                  - Radar systems        - Signal display
- Computer display - Waveform display (CRO)
The question was on Electron Emission and Thermionic Devices. It was quite
unpopular with the candidates. Quite a few candidates correctly responded to
this question.


Powered by Sidmach Technologies(Nigeria) Limited .
Copyright © 2015 The West African Examinations Council. All rights reserved.