08. Current Electricity

a flow of electric charge.

*An electric current in a metal conductor is a flow of electrons.

The amount of charge passing any point of a conductor per second.

*The current is the same at
every point in a series
circuit.

*Connected in series

Joule per coulomb (J C⁻¹)
AND
Volt (V)

*The P.D between two points in
a circuit is the energy lost by
one coulomb as it moves
from one point to the other.

*A voltmeter is always connected in parallel with the part of the circuit
across which the p.d. is to be measured.

A voltage when applied to a circuit

The ratio of the potential difference to current.

A conductor has a resistance of 1 ohm if the current through it is 1 A when the p.d. across it is 1 volt.

ρ = RA ÷ l

ρ= Resistivity
R = Resistance
A = Cross sectional area
l = Length

states that at a constant temperature, the current flowing through a conductor is directly proportional to the potential difference.

*(know like 2 maybe)
• Temperature Control (Thermostat)
• Flame failure device
• Fire Alarm
•Strain Gauge

states that the rate at which heat is produced in a conducor is directly proportional to the square of the current provided its resistance is constant

A charged atom or group of atoms

*Positive and negative ions

Current that flows in one direction only

Current that constantly changes direction

The amount of energy used by a 1000 W appliance in 1 hour