Topic 2 Electricity Within a Circuit. Static and Current Electricity: When charged particles build up in an object it is called static electricity. Another.

Topic 2 Electricity Within a Circuit

Static and Current Electricity:

When charged particles build up in an object it is called static electricity. 

Another kind of electricity occurs when electrons flow in a current.  • A battery and wires can make current flow

What is an electric current?

An electric current is the flow electrons flowing

through wires and components.

+ -

In which direction does the current flow? from the Negative terminal to the Positive terminal of a cell.

Current Electricity 

•As electrons pass through the wire and into the light bulb, the filament lights the bulb

simple circuits

simple electric circuit: It has a cell, a lamp and a

switch.

Circuit: components are connected together with

metal wires

cell

lamp

switch

wires

simple circuitsWhen the switch is closed, the lamp lights up. This

is because there is a continuous path of metal for the electric current to flow around.

If there were any breaks in the circuit, the current could not flow.

circuit diagram:

cell switch

lamp

wires

Scientists usually draw electric circuits using symbols;

circuit diagramsIn circuit diagrams components are represented

by the following symbols;

cell battery

switch

lamp

motorammeter

voltmeter

buzzer

resistor

variable resistor

measuring current

Electric current is measured in amps (A) using

an ammeter connected in series in the circuit.

A

measuring current

A A

This is how we draw an ammeter in a circuit.

SERIES CIRCUIT PARALLEL CIRCUIT

Lets give electrical diagrams a whirl…

DRAW THISELECTRICAL

CIRCUIT

DRAW THISELECTRICAL

CIRCUIT

Consider this to be a Switch

Label the circuit components

A

Label the circuit components

A

Haha, just kidding

measuring voltageThe ‘electrical push’ which the cell gives to the

current is called the voltage. It is measured in

volts (V) on a voltmeter. It provides the energy

for the moving electrons.

Voltage is also referred to as “Potential

Difference”

V

Different cells produce different voltages. The

bigger the voltage supplied by the cell, the bigger

the current.

measuring voltage

Unlike an ammeter a voltmeter is connected

across the components

Scientist usually use the term Potential

Difference (pd) when they talk about voltage.

Thinking of Electricity like Water

Current is literally just the amount of water flowing through a channel. - This is analogous to electricity flowing through a wire

Less water means less water molecules

are flowing

More water means more water molecules are

flowing

Amps (or amperes) measures current – the amount of electricity flowing through some point.

Amperes are measured in coulombs per second.

Just like measuring amps of

electricity, you could set up a flow meter to

measure exactly how much water is flowing past

this point

Volts• Voltage is analogous to water pressure • Voltage is the force that moves the electrons through the wire. Increasing

voltage increases current (electron) flow

water which falls from a high

waterfall has more pressure

than water which falls over the edge

of small rocks

9V 1.5V

WattsWatts = A measure of power / the rate of energy consumed by an electrical device when it is operating

Watts are calculated by multiplying the voltage at which an appliance operates (i.e. 1.5 V) by the current it draws