Chapter 6-Electricity Flashcards
Current
The rate of flow of charge or the amount of electric charge passing any one point through a circuit in one second.
Coulomb
The charge is the quantity of electrical charge which passes any point in an electrical circuit in one second when a steady current of one amp is flowing.
Potential difference (p.d.)
The work done (energy transferred) in a moving unit charge between two points.
E.m.f. (Electromotive force)
How much energy the charges per unit charge gains. When a charge moves around an electrical circuit it needs energy to do so.
P.d. across its terminals when no current is flowing through.
One volt
When a charge of one coulomb flows and releases one joule of energy.
Resistance
For a metallic conductor with physical conditions kept constant, for example temperature, the current is directly proportional to the potential difference across its ends.
Which law is about resistance?
Ohm’s Law
What does Ohm’s Law state?
For a metallic conductor kept at a constant temperature, the current is directly proportional to the potential difference across its ends.
Forward biased
The direction which the current is allowed to flow.
Kirchhoff’s First Law
The sum of the currents entering the point in a circuit is equal to the sum of the currents leaving the same point.
Kirchhoff’s Second Law
The algebraic sum of the potential difference drops around a closed loop is equal to the algebraic sum of the e.m.f s.
Power
The rate at which electrical energy transferred per second.
External resistance
Total resistance in the external circuit.
Internal resistance
The resistance inside the battery.
Terminal p.d.
Voltage available from battery when current flows.
