Basic Electronics Paper 2, WASSCE (SC), 2023

Question 2

       

  1. A single phase a.c. supply at 220 V, 50 Hz is applied to a series circuit consisting of 0.02H inductor and 15 Ω resistor. Calculate the:

    (a) inductive reactance of the circuit;

    (b)impedance of the circuit;

    (c)current in the circuit;

    (d)potential difference across the inductor;

    (e)potential difference across the resistor.

 

OBSERVATION

 

The expected responses were:
For a single phase a.c. supplied series circuit
Voltage = 220 V,
Frequency = 50 Hz
Inductor = 0.02 H
Resistor = 15 Ω
(a) inductive reactance of the circuit;
XL = 2πfL                                                                        
       
                    = 6.28 Ω                                                                              

  1. Impedance of the circuit;

                                                                     
 
 
 
                                                             

  1. current in the circuit;

                                                                        
 
                                                                                

  1. potential difference across the inductor;

                                        

                                                

  1. potential difference across the resistor.

                                          VR =                    
                       OR           =
                                = 203.0 V                         

This was well attempted by very many candidates. Only very few of those who attempted this question did not get either XL. Z, I, and/or pd across L and R correctly. Many did not put the unit of each answer.