Electronics Paper 2, Nov/Dec. 2014  
Questions: 1 2 3 4 5 6 7 Main
General Comments

Question 7


(a)      Explain with the aid of a block diagram, the operation of a closed
          loop system.
(b)     Classify the following into open and closed loop system:
          (i)      water heater;
          (ii)      electric pressing iron;
          (iii)     remote control device;
          (iv)     microwave oven;
          (v)      switch.
The expected answers were:


In a closed loop control system, part of the output is used to effect changes of the controlled variable.


Open loop

Closed loop

Water heater

Electric pressing iron

Remote control device

Microwave oven



The question was on Communication Systems. The question was unpopular. The performance of the very few candidates that attempted it was average.

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