26 terms

# Electric Circuits

Definition of Electric Circuits
###### PLAY
Electric Current
rate fo flow of electric charge
Ampere
One ampere is the amount of current flowing in each of two infinitely-long parallel wires of negligible cross-sectional area separated by a distance of one meter in a vacuum that results in a force of exactly 2*10^-7 N per meter of length of wire.
Current
Current is defined in terms of the force per unit length between parallel current-carrying conductors.
Closed Circuit
complete pathway for current
Open Circuit
incomplete pathway for current
break in circuit
infinite resistance
Short Circuit
Circuit with little to no resistance - extremely high current overheating
Resistance
ratio of potential difference applied across a piece of material to the current through the material
Power
energy per unit time
Ammeter
measures currents
Placement of Ammeter
must be placed in series to allow current to flow through it
Ideal Ammeter
has zero resistance so it will not affect current flowing through
Voltmeter
measures potential difference
Placement of Voltmeter
must be placed in parallel to measure potential difference between two points circuit does not to be broken
Ideal Voltmeter
has infinite resistance so it will not allow any current to flow through it and disrupt circuit
Potential Divider
resistors in series act as 'potential divider'. they split the potential of the source between them.
Light-Dependent Resistor (LDR)
Light Sensor
a photo-conductive cell made of semiconducting material whose resistance decreases as the intensity of the incident light increases
Negative Temperature Coefficient (NTC) Thermistor
Temperature Sensor
a sensor made of semiconducting material whose resistance decreases as its temperature increases
Strain Gauge
Force Sensor
a long thin metal wire whose resistance increases as it is stretched since it becomes longer and thinner
Resistance
ratio of potential difference applied across a piece of material to the current through the material
Ohm's Law
for a conductor at constant temperature, the current flowing through ti is proportional to the potential difference across it
Ohmic Device
a device that obeys Ohm's law for a wide range of potential differences (a device with constant resistance)
Non-Ohmic Device
a device that does not obey Ohm's law (resistance is not constant)
Potentiometer
a tie of variable resistor with three contact points (use as a potential divider)
Electromotive Force (emf)
total energy per unit charge supplied by the battery
Terminal Voltage
potential difference across the terminals of the battery
Ideal Behavior
terminal voltage always equals emf since no internal resistance