Electric Current
The continuous flow of charge in a circuit, measured in amperes (A).
Average Current
Iavg = change in charge/change in time
Battery
A battery is a device that maintains an electric potential difference between the two terminals.
Voltage
The electric potential difference between two points in a circuit, measured in volts (V).
Ohmâs Law
V = IR
R is the resistance in the circuit.
V is the potential difference in the circuit
I is the electric current
Resistance
It is the impedance to the flow of electricity through a material. Asa charge moves through a material, it eventually hits a non-moving nucleus in the material.
Equivalent Resistance
The resulting resistance when two or more resistors are combined in a circuit.
Resistors in Series
Resistors arranged sequentially in a circuit, resulting in a total resistance equal to the sum of individual resistances.
Resistivity
It can be thought of as the density of nuclei the electrons may strike.
R = Ï l / A
R = resistance of the circuit
Ï = resistivity
l = length
A = cross-sectional area
low resistivity
conductors
high resistivity
insulators
Resistors in Parallel
Resistors arranged in branches in a circuit, resulting in a total resistance less than the smallest individual resistance.
Ammeter
A device with low resistance used to measure electric current in a circuit.
Power Dissipation
The power dissipated by a circuit component, calculated as the product of current and voltage:P = VI.
Voltmeter
A device used to measure the electric potential difference in a circuit.
Ohm's Law
The relationship between potential difference (V), current (I), and resistance (R) in a circuit:V = IR.
Capacitance
C =Â QV
C = refers to the capacitance that we measure in farads
Q = refers to the equal charge that we measure in coulombs
V = refers to the voltage that we measure in volts
Besides, there is another formula that appears like this:
C = kΔ0Ad
C = refers to the capacitance
K = refers to the relative permittivity
Δ0 = refers to the permittivity of free space
A = refers to the surface area of the plates
d = refers to the distance between places measured
Capacitors in parallel
Cp = C1 + C2
Capacitors in series
1/Cs = 1/C1 + 1/C2
Name three possible energy sources for a circuit
Battery
Photoelectric cell
Generator
What will happen to the charges in a circuit when a switch is closed?
The charges will flow through the circuit.
What will happen to the charges in a circuit when a switch is open?
The circuit is broken and the charges stop flowing through the circuit.
What is the standard voltage per branch in a home in the United States?
120V
A switch that automatically opens if the current is too high is a ________________
Circuit Breaker
The symbol used to represent resistance in a schematic diagram is
The symbol used to represent resistance in a schematic diagram is
When two light bulbs are connected in series, the
same amount of current always flows through each bulb
When resistors are put in parallel with each other their overall resistance is
smaller than the resistance of any of the resistors
As more lamps are put into a series circuit, the overall current in the circuit
decreases
As more lamps are put into a parallel circuit, the overall current in the circuit
increases
When one light bulb in a parallel circuit containing several light bulbs burns out, the other light bulbs
burn the same as before
Electrical devices in our homes are connected in
parallel