Physics - Electricity

What is charge?

The amount of electricity flowing through a metal wire.

⤷ Measured in coulombs

What is the Charge equation?

Charge (Q) = Current (I) x Time (t)

⤷ Q = charge in coulombs(C)

⤷ I = current in amperes(A)

⤷ t = time in seconds(s)

What is current?

The rate of flow of electrical charge that passes a fixed point in a circuit every second.

⤷ Measured in amps

What is potential difference?

The amount of energy transferred by each unit of charge as it passes between two points in an electrical circuit.

⤷ Measured in volts

What are the requirements for current to flow?

• A source of potential difference

• A complete and closed circuit, with no gaps

What is the equation of Potential Difference?

Potential difference (V) = Energy Transferred (E) / Charge (Q)

⤷ V = potential difference in volts(V)

⤷ E = energy transferred in joules(J)

⤷ Q = charge in coulombs(C)

What is resistance?

The measure of how much a component opposes the flow of an electric current.

⤷ Measured in ohms

Ohm’s formula for potential difference.

Potential difference(V) = Current(A) x Resistance(R)

⤷ V = Potential difference in volts(V)

⤷ I = Current in amps(A)

⤷ R = Resistance in ohms(Ω)

Potential difference is…

Shared

⤷ V_total = V₁ + V₂ + ..

Current is the..

Same everywhere

⤷ I₁ = I₂ = ..

Resistance ..

Adds up

⤷ R _total = R₁ + R₂