Basic Electricity 2, WASSCE (SC), 2021

Question 2

 

  1. State one function of a choke in a fluorescent lamp.
  2. When an alternating voltage is applied to a circuit, the current produced lags the voltage by an angle ɸ. Illustrate this statement by means of:
    1. Wave diagram;
    2. Phasor diagram.
  3. State the effect of frequency increase on current flow in an inductive circuit.

 

Observation

The expected answers were:

  1. Function of a choke in a fluorescent lamp

A choke is used to provide high starting voltage between the filaments to make the lamp slow.                                                    

  1. (i)  Illustration of statement by means of diagrams     

            

 

           
(ii)   
Diagram  Description automatically generated                                                                

     Phasor Diagram

 


  1. Effect of frequency increase on current flow in an inductive circuit

It causes the current flow to decrease.           

Many candidates who attempted this question performed fairly well. However, some candidates had difficulty illustrating the statement.