Current and Potential Difference

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Current- the flow of electrical charge around the circuit.

Unit:ampere,A

Potential Difference- is the driving force that pushes the current around.

Unit: volt,V.

Resistance- is anything in the circuit that slows the flow of electrons down.

Unit: ohm,

The greater the resistance of a component, the smaller the current that flows (for a given potential difference)

The current is the amount of charge that flows through the circuit every second.

Current= Charge

Time

Current,I, measured in amperes(A)

Charge,Q,measured in coulumbs(C)

Time,t, measured in seconds(s)

The BIGGER the current the MORE charge that flows.

Potential Difference is the work done per coulomb of charge that passes between two point in a circuit.

So the Potential Difference across an electrical component is the amount of energy that is transferred by that electrical component per unit of charge

P.D= Work Done

charge

Potential Difference,V,measured in volts(v)

Work Done,W,measured in joules(j)

Charge,C,measured in coulombs(c)

In a series the total P.D of the supply is shared between the various components.

V= V1+V2.....

The current is the same everywhere.

A1 = A2

In a Parallel circuit the P.D is the same across all components.

V1 = V2 = V3

In parallel circuits the total current flowing around the circuit is equal to the total of all the currents through the separate branches.

A= A1+A2+...

Current and Potential Difference

Series Circuits

Parallel Circuits