Basic Electrical Enginerring

BASICS OF ELECTRICAL ENGINEERING (BEE)
DC CIRCUITS
 Sources (or) Active elements
 Passive elements(R,L,C)
 OHM’s law
 KCL & KVL
 Series circuits NAVARATANA of BEE
 Parallel circuits
 Voltage division rule
 Current division rule
 Source transformation technique
 Nodal analysis
 Mesh analysis
 THEVININ’S THEOREM
 NORTON’S THEOREM
 SUPER POSITION THEOREM


VOLTAGE(V):- potential difference between any two points is voltage. Units are
“volts” represented with “V”.

CURRENT(I):- the flow of electrons in a conductor is current. Units are “amperes”
represented with “I”.

POWER(P):- the product of voltage and current is the power. Units are “watts”
represented with “P”

P=V*I
Explain about active elements (or) source in a circuit?

Active elements (or) Sources: which energies the circuit .

, VDVS: VOLTAGE DEPENDENT VOLTAGE SOURCE

VDCS: VOLTAGE DEPENDENT CURRENT SOURCE

CDVS: CURRENT DEPENDENT VOLTAGE SOURCE

CDCS: CURRENT DEPENDENT CURRENT SOURCE
SYMBOLs:-


+ + +
- V=avx - V=bix V=cix - I=dix



VOLTAGE CURRENT
VDVS VDCS CDVS CDCS
SOURCE SOURCE

Differentiate ideal and practical sources?
Explain about ideal source? Explain about practicl source?
IDEAL SOURCE:-The sources have zero PRACTICAL SOURCE:-The sources
operational losses. have operational losses depends on
Voltage source have resistance zero(R=0) resistance & operational time.

current source have resistance zero(R=∞)
V I R
R=0 V I
+ +
V- I R=∞ V
- R

Voltage source I current source V Voltage source current source V
I

,Write a short note on passive elements? relations with Voltage,current &Power?
Passive Elements :-

Resistance(R):-
 the element which oppose the flow of current(i) in the circuit
 it dissipates power in the form of heat
 the units of resistor is OHM‟s (Ω).
 It denoted with letter “R”
By ohm‟s law V = I*R or Resistance(R)


Note:- here the resistor value is 4.7KΩ(4.7*1000 = 4700Ω)

Inductor(L):-
 the element which oppose the sudden change in flow
of current(di/dt) in the circuit
INDUCTOR(L)
 it store power in the form of magnetic field
 the units of INDUCTOR is HENRY(H).
Note:- here the inductor value is
 It denoted with letter “L”
100mH(100/1000 = 0.1H)
or

CAPACITOR(C):-

 the element which oppose the sudden change in
Voltage(dv/dt) of the circuit
 it store power in the form of electric field
Note:- here the capacitor value is
 the units of CAPACITOR is HENRY(H).
(470*10-6 = 0.47mf [or]
 It denoted with letteVr “L”
0.00047F )
or

elements
Resistance Inductor capacitor
Parameter
1
V  Ldi dt 
C
VOLTAGE V=I*R V Idt

1  dv 
L
CURRENT I V I Vdt I  c 
R  dt 
1 1
POWER P V * I  I 2R V 2 R P  LI 2 P  CV 2
2 2

, OHM‟s law :
At constant temperature current flowing through a
conductor is directly proportional to applied voltage

then

Resistance Is always depends on the 3 parameters
length(L),area(A) and specific resistance(ρ) of a conductor



Kirchhoff’s Voltage Law(KVL) :-

Algebraic sum of voltages in a closed loop is zero
+ V1=2v -
+
VS =9v V2=4v
-

+ V3=3v -

Kirchhoff’s Current Law(KCL) :-

I4
I
Algebraic sum of currents at a node is zero



I3 I2 I1

Series Circuit:
In series circuit the current is same and voltage
is divide.

The equivalent resistance of series circuit is


Beside circuit