Index Number: ___________________________ Programme: _________________________________
UNIVERSITY OF ENERGY AND NATURAL RESOURCES, SUNYANI, GHANA
SCHOOL OF ENGINEERING
DEPARTMENT OF COMPUTER AND ELECTRICAL ENGINEERING
LEVEL 100: END OF SECOND SEMESTER EXAMINATION Part 1 - 2019/2020
Bachelor of Science (Agric/Mech/Comp/Electrical Engineering) /
Diploma Electrical Engineering
CENG 102: BASIC ELECTRONICS
16 July, 2020 - 24 July, 2020
[TOTAL=20 MARKS]
ANSWER ALL QUESTION
[20 Marks]
1.
i.
[8 Marks]
Explain five (5) applications of the hall effects
ii.
With the aid of a diagram, explain how a P-N Junction is form.
iii.
State five (5) application of PN Junction, and explain the property of the PN junction that make
those application possible.
iv.
Explain what carrier mobility is and elaborate on the factors that influence carrier mobility.
2.
[12 Marks]
a.
A 80 V rms is stepped down to 18V rms by a transformer. The output from the transformer is
rectified using a half wave rectifier circuit and connected to a 47.5 Ω load resistor.
Draw a circuit diagram of this arrangement and the waveform at each stage.
b.
Calculate the following about the circuit in Figure 2.1 (If silicon diodes are employed in the
rectification);
i.
the peak value of the output voltage considering the drop across each diode, Vpk.
ii.
the average voltage, Vdc.
iii.
The current through the load resistor, IL.
iv.
The current diode, Id.
v.
The frequency of the output signal, Fout.
vi.
Calculate the efficiency of the full wave rectifier expressed in percentage.
vii.
c.
Sketch a graph of the input and output voltage against time.
If a 480 𝜇F capacitor is added to the output in Figure 2.1, calculate the following:
i.
Vripple.
ii.
Average voltage, Vdc.
iii. Sketch a graph of the input and output voltage against time of the capacitor.
(Built-in-potential of silicon = 0.7V)
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Joseph Owusu
Index Number: ___________________________ Programme: _________________________________
Figure 2. 1
INTRUCTIONS:
1. The answers are to be hand written and a clear picture taken and converted into a single pdf file.
2. The file should be save with the course code_index number only_programme (No names
included). Example: CENG102_UE20000001_ComputerEng
3. DO YOUR INDEPENDENT WORK. Any copied work will be PENALIZED.
End of Examination
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Joseph Owusu