Network Terminology & Basic Concepts

Question 1

Electrical Circuit:

Answer 1

An electrical network with at least one source and
a sink and having a closed path for current flow.

Question 2

Active Element:

Answer 2

An element which supplies or delivers energy in an
electrical network.
Eg: Voltage Sources & Current Sources

Question 3

Passive Element:

Answer 3

An element which absorbs or stores energy in an
electrical network.
Eg: Resistors, Inductors & Capacitors

Question 4

Ohms law

Answer 4

At a constant temperature, the potential difference across the
terminals of a conductor is directly proportional to the current
flowing through it

Question 5

Conductance formula and unit

Answer 5

G = 1/𝑅
It is measured in Siemens (S)

Question 6

Current divison rule formula

Answer 6

I1 = 1sR2 /(R1+R2)
I2 = 1sR1 /(R1+R2)

Question 7

Ideal voltage source principles

Answer 7

Its terminal voltage is independent of current flowing through it.

The current delivered by it depends on the circuit to which it is
connected.

Question 8

Ideal Current Source principles

Answer 8

Its current is independent of the voltage across it.

The voltage across it depends on the circuit to which it is
connected.

Question 9

KCL current law

Answer 9

At every node in an electric network, the algebraic sum
of currents is Zero (or) sum of incoming currents is equal to the sum
of outgoing currents”.

Question 10

node

Answer 10

A point at which two or more elements are interconnected is a node

Question 11

KVL voltage law

Answer 11

Around every closed path in an electric network, the
algebraic sum of voltages is Zero

Question 12

Voltage drop(+ to -) and Voltage gain signs(- to +)

Answer 12

Voltage drop is considered negative and voltage rise as
positive.

Question 14

voltage divsion rule formula

Answer 14

V1 = VsR2 /(R1+R2)
V2 = VsR1 /(R1+R2)

Question 15

what are the current and voltage values of open circuit

Answer 15

Current is Zero.

Voltage across the can be any finite value.

Question 16

What is a short circuit

Answer 16

A short circuit happens when electricity takes a shorter path than intended, creating a connection between two points in a circuit.

Question 17

what are the current and voltage values of short circuit and resistance

Answer 17

Voltage across a Short Circuit is Zero.

Current through the Short Circuit can be any finite value.

resistance = 0

Question 18

what happens to terminal voltage as current increases

Answer 18

terminal voltage falls

Question 19

how is terminal voltage modelled

Answer 19

It is modelled as an ideal voltage source in series with
internal resistance.

Internal resistance is small, usually few mΩ.

Internal resistance of an ideal voltage source is Zero

Question 20

how does terminal current source as load voltage increases

Answer 20

current decreases

Question 21

how is terminal current modelled

Answer 21

It is modelled as an ideal current source in parallel with
internal resistance.

Internal resistance is very high, usually few Mega Ohms

Internal resistance of an ideal current source is Infinite

Question 22

what is a delta connection

Answer 22

a connection in which three elements in series form a triangle, the supply being input and output at the three junctions.

When three resistors are connected at one common termina

Question 23

what is a star connection

Answer 23

the windings each have one end connected to a common junction, and the other end to a separate terminal.

Question 25

delta to star if all the values = what value

Answer 25

1/3 of delta = star resistor

Question 26

in mesh calculation is the voltage taken conventional or normal

Answer 26

its taken conventional (+ to -)

Question 27

what is Superposition Theorem

Answer 27

“In a linear network with more than one independent
source, the total response in any element is the algebraic
sum of the individual responses caused by each
independent source acting alone, while all other
independent sources are replaced by their internal
resistances i.e., all other ideal voltage sources with short
circuit and all other ideal current sources with open circuit.
”

Question 28

what is Thevenins theorem

Answer 28

“A linear network with a large number of independent and
dependent sources and resistors between two terminals
can be replaced with a simple two element series
equivalent in which a voltage source called ‘Thevenin’s
Equivalent Voltage’(VTH)is in series with a resistance called
‘Thevenin’s Equivalent Resistance’ (RTH).”

Question 29

thevenin current formula

Answer 29

IL =Vth/Rth+R(load)