Electricity

Electricity Is a natural form of energy that can take

many different forms. It is defined briefly as the flow of electric charge.• Lightning is a natural electrical charge of

very short duration and high voltage.• Static electricity is produced by friction

and causes sparks.• Electromagnetic field is a physical field

produced by electrically charged objects. It affects the behaviour of the charged objects in the field.

Electric Charge

The movement of electric charge is known as an electric current.

A current can consist of any moving charged particles; most commonly these are electrons, but any charge in motion constitutes a current.• Amperes (amps)= AMOUNT of electricity used• Voltage (volts)= FORCE of electricity• Wattage (watts)= WORK that electricity does per

second. Watts= Amps x Volts

Static Electricity

Law of Attraction and Repulsion• Charges that are the same will repel each other and charges that are different will attract each other.

Static Electricity Electroscope

• Detects the presence of charge.• When the metal leaves become

charged they repel each other.• So when the leaves move apart, you

know that they are charged.• Induction – movement of electrons

within a substance caused by a nearby charged object, without direct contact.

Electric Circuit

An electric circuit is an interconnection of electric components, usually to perform some useful task, with a return path to enable the charge to return to its source.

Circuit Diagram Symbols Conducting wire

Battery

Lamp

Ammeter

Voltmeter

Resistor

Switch

VA

Current

Current is the movement of charge (electrons)

In comparison to a current of water, it would be the number of litres that flow past a point in the pipe every minute.

Current is the amount of charge that passes a point in a conducting wire every second.• How do we measure current?

Conductors and InsulatorsConductor: An object or substance which conducts or leads electric current. A wire, cable, rod, or tube can serve as a path for electricity to flow. The most common conductor is an electrical wire.

Insulator: An insulator is a device through which electricity cannot easily pass. An example would be porcelain support used to insulate conductors from a pole or tower. An insulator can be constructed of material such as porcelain, glass, rubber, and wood.

Voltage Voltage: The force that moves electric

charges (electrons) in a circuit.

Potential Difference = difference in the potential energy (voltage) per electron at one point in the circuit compared to another point in the circuit.

Voltmeter: Measures the potential difference (voltage) between two locations in a circuit.

Series and Parallel Circuits

A series circuit has only one path along which electrons can flow. Each load in the circuit uses a portion of the total voltage supplied by the battery.

Parallel circuits are arranged so that electrons can flow along more than one path. Each load uses all the voltage supplied by the battery.

Schematic Diagram: Diagram using symbols, lines and numbers to help identify circuit created.

LED: A semiconductor diode that converts applied voltage to light and is used in digital displays, as of a calculator. Light Emitting Diode.

Battery: Two or more connected cells that produce a direct current by converting chemical energy to electrical energy. A single cell, such as a dry cell, that produces an electric current.

Current: The movement of an electric charge from a source of electrical energy along a controlled path.

Ammeter: a device that measures the amount of electric current flowing past a point in a circuit.

Ground: A ground happens when one or more conductors touch the earth causing the electricity to flow out of the circuit and into the earth.

Load: A load is the amount of power delivered, as required, at any point or points in the system. A load is created by the power demands of customer equipment.

Circuit (CKT): A circuit is a path through which electricity travels.

Amperes (Amps): AMPS are the amount of electricity or current flowing through a wire, similar to the flow of water through a pipe.