Circuit Fundamentals Flashcards
Ohm’s law
Current (I) is a proportion of voltage (E) and resistance (R)
What is the mathematical expression of Ohm’s law?
I = E/R
What is the basic power formula/Watt’s law?
The rate at which a load consumes energy is determined by current and voltage.
What is the mathematical expression of Watt’s law?
P = E x I
What is the mathematical formula for work?
W = P (a certain amount of power) x t (applied for a certain period of time)
In a series circuit, the total resistance is equal to ________.
The sum of the individual resistance within the circuit
In a series circuit, the current is ________.
The same throughout
The total voltage at the source of a series circuit is equal to _______.
The sum of the voltages at each of the resistor
What is the main disadvantage of series circuits?
A fault in the circuit stops the current in the entire circuit.
Branch
A pathway in a parallel circuit
What is the main advantage of parallel circuits?
A fault in any branch of the circuit doesn’t stop the current to other branches
The voltages across all branches of a parallel circuit are equal to _______.
The Source Voltage
The total current in a parallel circuit is equal to ___________.
Sum of the current flowing through each branch
The total resistance in a parallel circuit is ________________.
The reciprocal of the sum of the reciprocals of the separate resistances in parallel.
Complex circuit
Combines loads in parallel with loads in series in a single circuit
How do we analyze complex circuits?
By reducing the parallel circuits into an equivalent series circuit
As Current (I) increase, resistance __________
Decreases
Describe the Ohm’s Triangle
Current (I)
The continuous flow of free + electrons through a conductor
Voltage (V)
The motivating force, PRESSURE, causing electrical current
Current (I) is measured in …
Amps
As current increases, voltage…
Increases
Electron current flows from
Negative to Positive
Electron current flows from???
Negative to Positive
Voltage is expressed as…
V or I
Electric current is measured in…
Amps
Voltage is measured in…
Volts
Resistance is measured in…
Ohms
Voltage and Resistance are a measure of…
potential difference “between” or “across” two points in a circuit
The standard unit of measure of resistance is the …
Ohm
The standard unit of measure current is the…
Amp
Power is a measure of???
The amount of work that can be performed in a given time
Work is the amount of???
weight lifted against gravity
Power is the measure of ???
The speed of a standard amount of work
Power is a function of???
Voltage and Current
Electrical power is measured in???
Watts
kW
1,000 Watts
1 HP =
745.7 Watts
The formula for Power (P) is…
P=IE
The formula for electrical power (Watts) is…
Watts = Amps x Volts
If current and resistance is known, Power =
If voltage and resistance are know, Power =
Conventional current direction flows???
Positive to negative
The symbol for a Resistor is…
The symbol for a Capacitor is…
The symbol for an Inductor is…
3 Current-Voltage/time circuit elements?
Resistor, Capacitor, Inductor
The formula for Resistance (R)
The formula for Capacitance (C)
The formula for Inductance (L)
The symbols for Constant Voltage…
The symbol on the left is used for a battery. The circle symbol represents some other source of voltage, often a power supply.
The symbol for Constant Source…
The arrow indicates the direction of positive current flow
The symbol for Variable Voltage Source…
Variable Voltage Equation
v = v(t)
Constant Voltage Equation
v = V
Constant Current Equation
i = I
The formula for power in a resistor
The formula for energy in a capacitor
The formula for energy in an inductor
A node is a…
A junction where 2 or more elements connect in a circuit
A branch in a circuit…
the connections between nodes
Mesh is…
A loop that has no other loops inside it
Loop…
the number of meshes and closed paths in a circuit
Reference Node
Voltage is measured relative to the reference node
2 common Reference Nodes are
1) - terminal of the voltage or current source
2) the node connected to the greatest number of branches
Ground is the reference point from which ________ is measured
Voltage
The return path for electric current back to its source is…
Ground
The direct physical connection to the Earth
Ground
Common Ground symbols
To be equivalent, two schematics must:
Represent every component and source
Have the same number of nodes
Each node must be connected to the same branches
A passive component does not …
Create power or amplify a signal
Series Resitors are connected …
Head to tail
A parallel resistor shares the same…
node and voltage
