Network Terminology & Basic Concepts Flashcards
Electrical Circuit:
An electrical network with at least one source and
a sink and having a closed path for current flow.
Ohms law
At a constant temperature, the potential difference across the
terminals of a conductor is directly proportional to the current
flowing through it
Current divison rule formula and for I1 is it R1 or R2
voltage division rule
I1 = 1sR2 /(R1+R2)
I2 = 1sR1 /(R1+R2)
V1 = VsR2 /(R1+R2)
V2 = VsR1 /(R1+R2)
Ideal voltage source principles
Ideal Current Source principles
Its terminal voltage is independent of current flowing through it.
The current delivered by it depends on the circuit to which it is
connected.
Its current is independent of the voltage across it.
The voltage across it depends on the circuit to which it is
connected.
KCL current law
KVL voltage law
and what is node
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”.
Around every closed path in an electric network, the
algebraic sum of voltages is Zero
NODE
A point at which
two or more elements are interconnected is a node
Voltage drop(+ to -) and Voltage gain signs(- to +)
Voltage drop is considered negative and voltage rise as
positive.
what are the current and voltage values of open circuit
what are the current and voltage values of short circuit and resistance
Current is Zero.
Voltage across the can be any finite value.
resistance is infinte
short circuit
Voltage across a Zero.
Current can be any finite value.
resistance = 0
What is a short circuit
A short circuit happens when electricity takes a shorter path than intended, creating a connection between two points in a circuit.
how is terminal voltage modelled
what happens to terminal voltage as current increases
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
terminal voltage falls
how is terminal current modelled
how does terminal current source as load voltage increases
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
current decreases
delta to star if all the values = what value
1/3 of delta = star resistor
in mesh calculation is the voltage taken conventional or normal
its taken conventional (+ to -)
what is Superposition Theorem
“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.
”
what is Thevenins theorem
thevenin current formula
“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).”
formula:
IL =Vth/Rth+R(load)
What is the best way to make a long chain circuit simple
Starting and ending node should be in a straight line
Lettering of nodes should be in such a way that it follows one path from start to finish
Start making parallel series from start and see where the other elements connect
