Question 3.
(a)
- (i)Name the parts labeled X and Y.
- (ii)Determine the frequency of the waveform.
(b)An alternating voltage has a peak value of 4.0kV. Calculate its:
- (i)average value;
- (ii)r.m.s value.
(c)
(ii) Copy and complete Table 1 by marking with a tick “√” the mode of fault indication for each equipment. The first one has been done for you.
(i)List any three electronic measuring instruments.
Fault finding equipment |
Visual indication |
Audio indication |
Tester |
|
|
Logic probe |
|
|
TV analyzer |
|
|
Signal tracer |
|
|
Oscilloscope |
|
|
Observation
The expected answers were:
- (i) X – Period;
Y – Amplitude
(b) Using the Kirchhoff’s Current Law:
(i)Vavg = 0.637Vpeak
= 0.637 x 4000
= 2,548V.
(ii)
(c)
(i) Electronic measuring instruments
• Ammeter
• Ohmmeter
• Voltmeter
• Multimeter
• Oscilloscope
(ii) Fault finding equipment and mode of fault indication
Fault finding equipment |
Visual indication |
Audio indication |
Logic probe |
√ |
|
Signal tracer |
|
√ |
TV analyzer |
√ |
|
Oscilloscope |
√ |
|
Many candidates did not show an understanding of the relationship between Vpeak, Vavg and Vr.m.s. . More so, candidates did not show good understanding of the mode of fault indication of fault finding equipment.