BASIC ELECTRONICS
ASSIGNMENT
MULTISIM
1. With the knowledge you’ve gained in basic electronics, design and simulate a
circuit that comprises of a transformer, diode, capacitor, voltage regulator, zener
diode, transistors and any other vital components needed to make the circuit work.
A. Explain how the circuit you’ve built works
B. Describe the function of each of the components in the circuit.
2. As a electronic engineer, design a circuit where the transistor as a switch and
another where the transistor is for amplification.
TRANSISTORS
1. Draw the equivalent circuit for a common-emitter bipolar transistor amplifier and
derive suitable formulae for the amplifier current gain, voltage gain and power gain.
Neglect bias, decoupling and coupling components.
2. An amplifier has the following parameters: input resistance, 470 kΩ; output
resistance, 8.2 kΩ; opencircuit voltage gain 50. A signal source having an e.m.f. of 75
μV and negligible internal resistance is connected to the input of the amplifier. The
output is connected to a 10 kΩ resistive load. Draw the equivalent circuit and hence
determine: (a) the output voltage developed across the load; (b) the current gain (c)
the voltage gain.
3. In a CE transmitter amplifier, if the amplification factor is 100 and the collector
voltage is 4 V and resistance is 5 kΩ, what should be the value of RB, given that the
dc base current is 10 times the signal current?
4. The transistor in the circuit below is biased at a dc collector current of 0.5 mA.
What is the voltage gain?
5. For a BJt Vt is 5 V, Rc = 1200 ohm and bias current Ic is 15 mA. What is the
voltage gain ?
6. A transistor with &szlig; = 100 is biased to operate at a dc collector current of 1.2 mA.
Find the value of gm.
7. A transistor operating with nominal gm of 70 mA/V has a &szlig; that ranges from 60 to
300. Also, the bias circuit, being less than ideal, allows a 20% variation in Ic. What is
the largest value found of the resistance looking into the base?
8. The circuit shown below is a small sine wave signal with average zero and
transistor &szlig; =
Find the value of R(E) to establish a dc emitter current of about 0.8 mA
9. Find R(C) to establish a dc collector voltage of about +100V.
10. For R (L) = 15 kΩ and transistor Ro = 200 kΩ, determine the overall voltage
gain.
11. Consider the figure shown below and answer the questions that proceed.
For Vcc = 20V, R1 = 120 kΩ, R(E) = 4.9 kΩ, R(C) = 6.8 kΩ and &szlig; = 100, determine
the dc collector current for each transistor.
12. For Vcc = 20V, R1 = 120 kΩ, R(E) = 4.9 kΩ, R(C) = 6.8 kΩ and &szlig; = 100,
determine the dc collector voltage for each transistor.
13.
solve for the following dc quantities:
a. V B(Q1) .
b. V E(Q1) .
c. I E(Q1) .
d. V C(Q1) .
e. V B(Q2) .
f. V E(Q2) .
g. I E(Q2) .
h. V C(Q2) .
14.
Solve for each of the following ac
quantities:
a. Z in .
b. r L .
c. g mo .
d. g m .
e. A V .
f. V out .
15. What are the major differences between the collector characteristics of a BJT
transistor and the drain characteristics of a JFET transistor?
16. a) Describe in your own words why IG is effectively zero amperes for a JFET
transistor.
(b) Why is the input impedance to a JFET so high?
(c) Why is the terminology field effect appropriate for this important three-terminal
device?
17.
For the network above, determine:
(a) ID.
(b) VDS.
(c) VD.
(d) VS.
18.
Given the information appearing above, determine:
(a) IC.
(b) VE.
(c) VCC.
(d) VCE.
(e) VB.
(f) R1.
19.
Given the information provided above, determine:
(a) IC.
(b) VE.
(c) VB.
(d) R1.S
Submission Date : 16th July 2020 before 6pm.