Electricity Flashcards
Electric current
The amount of charge per time that passed through a surface that is perpendicular to the motion of the charges.
Direct current (DC)
Charges move around the circuit in the same direction at all times. cell/battery
Alternating current (AC)
Charges move first one way and then the opposite way. Socket/domestically
Conventional current
The hypothetical flow of positive charges that would have the same effect in the circuit as the movement of negative charges that actually occur.
Electromotive Force
The maximum potential difference across the terminals
Potential difference
The amount of work done to move a unit charge from one point to another in a conductor.
Conditions for the flow of charge
- need a potential difference - electric field
- close circuit
- charges that are free to move.
Electric current strength
the rate of flow of a charge
Resistance
The ratio of the potential difference to the current strength in the conductor. The ration of the voltage applied across a piece of material to the current through a material. it resists the flow of charge though a conductor.
Resistor
The extend that a wire or an electrical device offers resistance to electrical flow.
Insulators
Much higher resistivity compared to conductor
Semiconductors
The resistivity lies between the conductor and insulator.
Conductors
Low resistivity
Series
The devices are connected in such way that there is the same electric current through each device. the current is the same but the voltage is different
Parallel wiring
The devices are connected in such way that the same voltage is applied across each device. The current divides. the voltage is the same
