Current electricity

In this lesson you will learn that:

• Circuit diagrams are used to show how electrical components are connected in a circuit.
• Individual circuit components are represented using circuit symbols.
• Current is the flow of electrons around a circuit.
• Ammeters are used to measure the current flowing through components. 
• Components in a circuit resist current flow.
• Voltmeters are used to measure the potential difference across components.

• Explore basic electricity relationships.
• Explain basic electricity relationships in series and parallel circuits.
• Use an ammeter and voltmeter to take readings in circuits.
• Provide reasoning to explain the measurements and relationships in circuits.
• Build circuits from schematic drawings.
• Determine if common objects are conductors or insulators.

• Explain basic electricity relationships in series and parallel circuits.
• Use an ammeter and voltmeter to take readings in circuits.
• Provide reasoning to explain the measurements and relationships in circuits.
• Build circuits from schematic drawings.
• Determine if common objects are conductors or insulators.
• Compare and contrast AC and DC circuits.
• Describe how capacitors and inductors behave in a circuit.
• Experimentally determine the RC time constant.
• Construct RLC circuits and determine the conditions for resonance.

• Predict how current will change when resistance of the circuit is fixed and voltage is varied.
• Predict how current will change when voltage of the circuit is fixed and resistance is varied.

This podcast (audio) file explains how electric current can be obtained from the sun through the solar panel using direct illumination of the sun rays

Most of us use electricity every day in many different ways so it is important that we understand the dangers, or hazards, associated with electricity and we know how to use it safely.

When a circuit is connected and complete, charge can move through the circuit. Charge will not move unless there is a reason, a force to drive it around the circuit. Think of it as though charge is at rest and some- thing has to push it along. This means that work needs to be done to make charge move. A force acts on the charges, doing work, to make them move. The force is provided by the battery in the circuit.

Electrical devices convert the electrical energy carried by the charges into other types of energy such as heat, sound, and motion. Components in the appliance resist the flow of charge and are referred to as resistors. In this unit1 you will understand what resistance is, the factors that affect the resistance and the relationship between resistance and current.

You have learnt about static electricity where charged particles (electrons) can move from one object into another giving objects an overall charge. In this unit1 you will learn about current electricity. This is when a continuous flow of charge can be created using a circuit made of conducting wires and an energy source.

The flicker of numbers on a handheld calculator, nerve impulses carrying signals of vision to the brain, an ultrasound device sending a signal to a computer screen, the brain sending a message for a baby to twitch its toes, an electric train pulling into a station, a hydroelectric plant sending energy to metropolitan and rural users—these and many other examples of electricity involve electric current, which is the movement of charge. Humanity has harnessed electricity, the basis of this technology, to improve our quality of life.