waecE-LEARNING
Home
Technical
Mathematics
Languages
Science
Social Science
Art
Literature Arabic Islamic Studies C.R.KHistory MusicVisual Art Clothing/Textile Home Management Shorthand
 
Applied Electricity 1, Nov/Dec 2009  
Questions:   1 2   Main
General Comments
Weakness/Remedies
Strength
































































Question 1

  1. Connect the circuit as shown in Fig.1.
  2. Ask the Supervisor to check the circuit.
  3. Copy Table 1 into your answer booklet.

 

Voltage Reading (V)

Ammeter Reading (mA)

0

 

2

 

4

 

6

 

8

 

10

 

12

 

                                                                                                  Table 1

  1. Adjust the variable power supply to read 0V on the voltmeter.
  2. Close switch S.
  3. Read and record in Table 1 the corresponding ammeter reading.
  4. Repeat steps (d) and (f) for voltage values as indicated in Table 1.
  5. Plot a graph of voltage (V) on the vertical axis against current (I) on the horizontal axis.
  6. Calculate the slope of the graph.
  7. Comment on the shape of the graph.
  8. Which law does the relationship in (i) obey?



_____________________________________________________________________________________________________
Observation

The candidates were required to

  1. connect the circuit shown and take ammeter readings;
  2. calculate the slope of the graph and comment on the shape of the graph;
  3. state the law the relationship in (i) obey.

 

The expected answers were:

Voltage Reading (V)

Ammeter Reading (mA)

0

0.000

2

166.700

4

333.300

6

500.000

8

666.700

10

750.000

12

833.300

From the results obtained, the graphical representation showed clearly that the graph was linear which is  in consonance with Ohm’s law.
The candidates understood the task, connected the circuit and obtained readings but the ill-understanding of the position of the pointer of the measuring instrument  was evident in the tables they came up with and the graphs plotted.

Powered by Sidmach Technologies(Nigeria) Limited .
Copyright © 2012 The West African Examinations Council. All rights reserved.