DC CIRCUITS Flashcards
A closed conducting path through which an electric current flows or is intended to flow.
-ELECTRICAL CIRCUIT
is an electric current that has no variation in amplitude (strength) of the current or voltage. One that remains constant with time.
-DIRECT CURRENT
Is one whose parameters are constant (i.e. They do not change with voltage and current.
-LINEAR CIRCUIT
Is that circuit whose parameters change with voltage and current.
-NON LINEAR CIRCUIT
Is one whose properties or characteristics are the same in either direction.
-BILATERAL CIRCUIT
Is that circuit whose properties or characteristics change with the direction of its operation.
-UNILATERAL CIRCUIT
Connection of various electric elements in any manner
-ELECTRICAL NETWORK
With no source of emf.
-PASSIVE NETWORK
Contains one or more than one sources of emf.
-ACTIVE NETWORK
supplies power at a constant voltage, regardless of the current drawn.
-IDEAL VOLTAGE SOURCE
is independent of the voltage between its terminals.
-IDEAL CURRENT SOURCE
deliver volatge and current at thier rated values regardless of circuit parameters.
-INDEPENDENT SOURCES
deliver volatge and current at levels determined by a voltage or current elsewhere in the circuit.
-DEPENDENT SOURCES
A junction in a circuit where two or more circuit elements and/or branches are connected together.
NODE
Part of a network which lies between two junctions.
BRANCH
A closed path in a circuit in which no element or node is encountered more than once.
LOOP
A loop that contains no other loop within it.
MESH
A progressive movement of free electrons along a wire or other conductor.
Also defined as the time rate of change of charge, measured in amperes (A).
-CURRENT
One in which there is no variation in amplitude (strength) of the current or voltage such as those generated from batteries, dc generators, and power supplies.
DIRECT CURRENT
One in which the amplitude of the current or voltage varies but never falls to zero. Found in many transistor and vaccum-tube circuits.
Varying direct current (Vdo) -
One in which the amplitude drops to zero periodically. Obtained in rectifier circuits.
Pulsating direct current (Pdc)
One in which current or volatge starts and stops abruptly (square wave). Produced by vibrators, choppers, and special oscillator circuits.
Interrupted direct current (idc)
Is a form of electricity that flows in an alternating directions and/or possessing a voltage with alternating polarity over time.
This is the usual house current.
-ALTERNATING CURRENT
assumes that current flows out of the positive terminal, through the circuit and into the negative terminal of the source.
-CONVENTIONAL CURRENT
electrons flow out of the negative terminal, through the circuit and into the positive terminal of the source.
-ELECTRON FLOW
Also known as electromotve force (emf) or potential difference is the elctron - moving force in a circuit that pushes and pulls electrons (current) through the circuit.
-VOLTAGE
Is the opposition to current flow. To add resistance to a circuit, electrical components called resistors are used.
-RESISTANCE
One of the most fundamental law in electrical circuits relating voltage, current and resistance
-OHM’s LAW
also known as the Joule effect, is a physical law expressing the relationship between the heat generated by the current flowing through a conductor.
-JOULE’S FIRST LAW
A circuit connection in which the components are connected to form one conducting path
-SERIES CIRCUITS
A circuit connection in which the components are connected to form more than 1 conducting path
-PARALLEL CIRCUITS
More comprehensive than Ohm’s Law and is used in solving electrical Termed as “Laws of Electric Networks” Formulated by German physicist
-KIRCHHOFF’S LAWS
A sophisticated application of KVL with mesh currents.
-MESH ANALYSIS
A systematic application of KCL at a node and after simplifying the resulting KCL equation.
-NODAL ANALYSIS
a node with three or more circuit elements joined together.
-PRINCIPAL NODE
the node from which the unknown voltages are measured.
-REFERENCE NODE
The current through or voltage across, an element in a linear bilateral network is equal to the algebraic sum of the current or voltages produced independently in each
source.
-SUPERPOSITION THEOREM
If the impedance Z of a branch in a network in which a current I flows is changed by a finite amount dZ, then the change in the currents in all other branches of the network may be calculated by inserting a voltage source of Idz into that branch with all other voltage sources replaced by their internal impedances.
-COMPENSATION THEOREM
If a voltage source E acting in one branch of a network causes a current I to flow in another branch of the network, then the same voltage source E acting in the second branch would cause an identical current I to flow in the first branch.
-RECIPROCITY THEOREM
A special case of the application of Thevenin’s Theorem/or Norton’s Theorem used for finding the COMMON voltage (VAs) across a network which contains a number of parallel voltage sources. “
-MILLMAN’S THEOREM
For loads connected directly to a DC voltage supply, maximum power will be delivered to the load when the resistance is equal to the internal resistance of the source.
-MAXIMUM POWER TRANSFER THEOREM
Any two-terminal of a linear, active bilateral network of a fixed resistances and voltage source/s may be replaced by a single voltage source (VTH) and a series of internal resistance (RTH).
-THEVENIN’S THEOREM
the open circuit voltage which appears across the two terminals from where the load resistance has been removed.
-VTH
the resistance looking back into the network across the two terminals with all
the voltage sources shorted and
replaced by their internal resistances (if any) and all current sources by infinite resistance.
-RT
” Any two-terminal active network containing voltage sources and resistances when viewed from its output terminals, is equivalent to a constant-current source (In) and a parallel internal resistance (RN).*
-NORTON’S THEOREM
the current which would flow in a short circuit placed across the output terminals.
-In
the resistance of the network when viewed from the open circuited terminals after
all voltage sources being replaced by
open circuits.
-Rn
The equivalent resistance of each arm to the wye is given by the PRODUCT of the two delta sides that meet at its end divided by the SUM of the three delta resistances.
-DELTA to WYE
The equivalent delta resistance between any two twrminals is given by the SUM of a star resistance between those terminals PLUS the PRODUCT of these two star resistances DIVIDED by the third resistance.
-WYE to DELTA
