YEAR 9 ELECTRICITY
revision notes !!
WHAT IS ELECTRICITY?
Electricity is the flow of electrons. (from negative to positive)
• Conductors promote the flow of electrons. Silver is the best.
• Insulators prevent/resist the flow of electrons. E.g. rubber and plastic
• To conduct electricity, a substance must have free electrons (metals have free electrons)
• Size of current depends on how may electrons move past a point.
WHAT IS AN ELECTRICAL CIRCUIT?
An electrical circuit is a closed loop that provides the path for the transfer of electrical energy
from a power source to an electrical component.
• It requires:
> Power source (battery or power point)
> Wires (to carry the energy
> Components (converts electrical energy into another type) e.g. light bulb
CIRCUIT DIAGRAMS
• Circuit diagrams show the arrangement of components.
• On the right is a simple circuit made up of a switch, battery and light bulb.
• It is important to use the correct symbols when drawing circuit diagrams.
TYPES OF CIRCUITS
There are two types of circuits:
• Series
• Parallel
, ELECTRICAL SYMBOLS
WHAT IS CURRENT?
Current is the flow of charge from one point to another (carried by wires)
• Current will always try to flow through regions of least resistance
• It is measured with an ammeter
• It is measured in amperes (amps)
• Its symbol is A
AMMETER
• Measure current
• They need to be connected in series
WHAT IS VOLTAGE?
Voltage is the amount of energy driving the current
• It is measured with voltmeter
• It is measured in volts
• Its symbol is V
revision notes !!
WHAT IS ELECTRICITY?
Electricity is the flow of electrons. (from negative to positive)
• Conductors promote the flow of electrons. Silver is the best.
• Insulators prevent/resist the flow of electrons. E.g. rubber and plastic
• To conduct electricity, a substance must have free electrons (metals have free electrons)
• Size of current depends on how may electrons move past a point.
WHAT IS AN ELECTRICAL CIRCUIT?
An electrical circuit is a closed loop that provides the path for the transfer of electrical energy
from a power source to an electrical component.
• It requires:
> Power source (battery or power point)
> Wires (to carry the energy
> Components (converts electrical energy into another type) e.g. light bulb
CIRCUIT DIAGRAMS
• Circuit diagrams show the arrangement of components.
• On the right is a simple circuit made up of a switch, battery and light bulb.
• It is important to use the correct symbols when drawing circuit diagrams.
TYPES OF CIRCUITS
There are two types of circuits:
• Series
• Parallel
, ELECTRICAL SYMBOLS
WHAT IS CURRENT?
Current is the flow of charge from one point to another (carried by wires)
• Current will always try to flow through regions of least resistance
• It is measured with an ammeter
• It is measured in amperes (amps)
• Its symbol is A
AMMETER
• Measure current
• They need to be connected in series
WHAT IS VOLTAGE?
Voltage is the amount of energy driving the current
• It is measured with voltmeter
• It is measured in volts
• Its symbol is V
