Basic Electronics Paper 2, WASSCE (PC 2ND), 2018

Question 7

 

  1. List two:
    1. components of a servo system;
    2. signals in a closed loop control system.
  2. Convert the binary 10100100 to its hexadecimal equivalent.
  3. Perform the following binary operations:

The expected responses were:

 

(a) (i)   Components of a servo system

  • Comparator
  • Actuator/amplifier
  • Servomotor
  • Feedback element                                          

   (ii)     Signals in a closed loop control system

  • Input /reference signal
  • Output signal
  • Feedback signal

                                               
(b) A4                                                                                                                  
(c) (i) 1100102
  . (ii) 1002

The Chief Examiner reported a fair performance of candidates in part (a), poor responses from candidates in part (b) and very good performance by majority of the candidates in part (c).