Electrical and Electronic Fundamentals: A Practical Approach

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Electrical and Electronic Fundamentals

Table of Contents
LO1.......................................................................................................................................................3
Task 1................................................................................................................................................3
LO2.......................................................................................................................................................9
Task 2................................................................................................................................................9
LO3.....................................................................................................................................................11
Task 3..............................................................................................................................................11
LO4.....................................................................................................................................................24
Task 4..............................................................................................................................................24
Table of Figure
Figure 1: ohm's Circuit Diagram...........................................................................................................3
Figure 2: Graphical Representation.......................................................................................................4
Figure 3 : KCL......................................................................................................................................5
Figure 4: KVL.......................................................................................................................................6
Figure 5: Circuit Diagram......................................................................................................................7
Figure 6: Circuit Diagram......................................................................................................................8
Figure 7: Thevenin's Theorem...............................................................................................................8
Figure 8: Diode....................................................................................................................................11
Figure 9: Forward Biasing...................................................................................................................12
Figure 19:Logic Circuit.........................................................................................................................26
Figure 20: Logic Circuit........................................................................................................................26
2

LO1
Task 1 A. Ohm’s Law
For conductor’s ,the electric current which flows through the conductor is directly
proportional to the voltage applied to the conductors.The ratio of voltage to current
gives resistance .If ratio is constant over a voltage applied to conductor then,it will be
ohmic material. (En.wikipedia.org, 2019)
The mathematical representation of resistance is :
R=V/I
Where,R=Resistance of conductor
V=Voltage
I=Current
Circuit Diagram of Ohm's law:
Figure 1: ohm's Circuit Diagram
(Source :Circuit Globe, 2019)
The Graphical representation of Ohm's law is:
3

Figure 2: Graphical Representation
( Source :Circuit Globe, 2019)
Above graph is also known as an i-v curve and the slope of this curve determines the
resistance and if the axes are changed then the slop is will 1/R.
 B. Kirchhoff Law
Gustav Kirchhoff was the physicist of German and have proposed the two laws
1. Current Law [KCL]
2. Voltage Law [KVL]
Current Law [Σ I = 0]
4

Figure 3 : KCL
(Source : Circuit Globe, 2019)
in the above graph when KCL is applied :- i1+i2-i3-i4-i5+i6=0
Voltage Current [ Σ E + Σ V = 0]
The algebraic sum of all EMF is equal to the sum of the of all the voltage drop (Circuit Globe,
2019)
Here, the voltage drop = R*I
Where R= resistance
I=current
5

Figure 4: KVL
( Source Circuit Globe, 2019)
From the above figure KVL :-
-V1 +(-V2)+iR1 + iR2 = 0
C: Practical Result
Figure 5: Circuit Diagram
(Source :CBSE, 2019)
6

here to solve this let us use the Kirchhoff Law of current that is first law
I3 =I2 +I1 ………………………….(1)
Let us take loop BDEA
-30I1 – 80 + 20I2 =0
- 3I1+2I2= 8…………………..(2)
Let us take a loop ACFB
-30I1 + 20 - 20I3 =0
3I1+2I3=2 …………………..(2)
Put the value of I3 in equation 1 and subtracting
We get,
8I1 = -6 ,I1 = -3/4A
Now I1 in equation (4)
I2 = 23/8 A
I3 = 17/8 A
Hence the Kirchhoff law of current is proved.
Figure 6: Circuit Diagram
(Source:CBSE, 2019)
here, to solve this the Kirchhoff Law of voltage KVL is applied
loop DCAB
7

VA + 1V +1*2-2 = VB
Now VA =0
Therefore VB =1
D. Thevenin’s Theorem
This law is for the linear circuit containing the lots of voltage and resistance can be replaced
by the single voltage in the series with the single resistance across the load.This theorem is
basically used for the battery system.(Anon, (2019)
Figure 7: Thevenin's Theorem
(Source: Circuit Globe, 2019)
here,
Rl = load resistor
Vs=Voltage Equivalent
Rs=Source Resistance
Step to analyse the Thevenin’s Theorem
1) Open the load resistor
2) Remove the Rl .
3) Finding the Rs and Vs .
4) Finding the current across the Rl.
8

LO2
Task 2
a).
1) For calculating the voltage resistor
The formula used v= I*R
Therefore given I= 40 mA
R= 200Ώ
Answer V= 8V
2) For calculating the voltage capacitor
As it has the resonance
Therefore, in this Vl=Vc
Here, Vl=0
Hence Vc =0
3) For calculating the voltage inductance
As, it has the resonance
Therefore, in this Vl=Vi
Here, Vl=0
Hence Vi =0
4. For calculating impedance
Z = R2(Xl –Xc)1/2
Z=200 ohm
5. The supply voltage.
(Sin(wt)dot – Vm +V)
= 8 volts.
9

6. To calculate the current
I= 8/200 sin wt.
I= 0.004 sin w.
7. Ɵ = 30.87 VM.
b) phasor diagram
V l
V l - V c
Vc
Θ= 30.87 from VM
10

LO3
Task 3
a).
 1. Diode
Figure 8: Diode
(Source: Electrical4u.com, 2019)
Basically, the diode is for, to conduct the electric current in one direction only either positive
or negative. Diode or semiconductors is mostly made up of silicon, germanium or selenium.
The diode consists of two electrodes 1) Cathode 2) Anode.
The usage of the diode is in rectifier, modulator,switches,voltage,regulators etc.
Semi-conductor diode can also produce the direct current which is also known as DC when
the infrared transmission or ultraviolet energy strikes to them.These diodes are known as the
photovoltaic cells because it consists of some solar energies.
The diode is of two terminals p-n junctions
There is one depletion layer ,where the p-n junction is created where there is no electric
charge is present,there is potential difference created .There is the forward biasing and the
reverse biasing .
11

Figure 9: Forward Biasing
(Source:Electrical4u.com, 2019)
 Backward current flows due to the minority charge and here the depletion layer is
increased.
12