Basic Electronics Paper 2, WASSCE (SC), 2022

Question 7

 

  1. (a)  Draw the circuit symbol of the following logic gates:

    (I)Ex-OR;

    (ii)Ex-NOR.

    (b)Draw the truth table for the Ex-OR logic gate.

    (i)Calculate the:

    (ii)sum of 11002 and 10002;

    (iii)difference between 11012 and 1112.

Observation

     

           The expected responses were:

  1. Logic Gate Symbols
  2.      EX-OR  

                                                             
(ii)   EX-NOR
                                                                       

  •             TRUTH TABLE

A

B

F

0

0

0

0

1

1

1

0

1

1

1

0

                         

 

                                                                                                             

 
(c) 
                     (i)
                                
                                                 
(ii)

OR   1102

                                                                                       

Question 7 required candidates to draw the diagrams of some logic gates, construct a truth table and also perform some operations on binary numbers. The Chief Examiner noted that majority of the candidates that attempted this question performed very well.