Basic Electronics Paper 2, WASSCE (SC), 2022

Question 1

 

  1. (a)  Define rectification.
    (b)  Figure 1 is a rectifier circuit diagram.
                                              
                                                           Figure 1

    1. Identify the component labelled Q.
    2. Sketch the output waveform.

    (c)     Component Q in Figure 1 can be replaced with a semiconductor equivalent to perform the `same functions.
    i.    Draw the circuit symbol of the equivalent component.
    ii.   State two advantages of this equivalent component in 1 (c)(i) over Q      

Observation

           The expected responses were:

  •      Rectification is the conversion of alternating current to pulsating direct current.      

 (b) (i) Vacuum tube diode | Thermionic diode | diode                                              

   (ii)  Output waveform
                       
                                                                                                                                                  
(c)        (i)        Semiconductor diode / PN junction diode


(ii)       Advantages of semiconductor diode over vacuum tube diode

      • It is more portable / smaller in size / not bulky
      • Less fragile / more rugged
      • Faster response/transient time
      • Less power consumption
      • Readily integrated
      • Lighter in weight
      • Cheaper | less expensive

  
                                          
Question 1 required candidates to define rectification and identify the parts of a rectifier. The Chief Examiner reported that a good number of the candidates responded well..