Electricity and Circuits Notes

What is Electricity?

  • Electricity is a form of energy that can accumulate or flow from one place to another.

  • When it builds up in one location, it's called static electricity; when it flows, it’s known as current electricity.

Static Electricity

  • Static electricity occurs when objects are rubbed together, causing an electric charge to build up.

  • For example, rubbing a balloon on a sweater transfers an electric charge, making the balloon stick to the sweater due to their opposite charges.

Current Electricity

  • Current electricity is the movement of electrons that carry energy from one location to another.

  • This type of electricity powers our everyday devices like washing machines, phones, and light bulbs.

  • Electrical appliances use wires, such as copper cables, to carry electric current.

  • The plastic coating on these cables protects you from electric shock.

  • Current electricity is similar to kinetic energy because it represents energy in motion.

  • For instance, when you turn on a flashlight, energy from the battery flows to the lamp, allowing it to emit light until the battery runs out of energy. This flow of electricity also generates heat due to resistance in the wires, which can sometimes be harnessed for heating purposes in devices like toasters or electric stoves.

Class discussion: Conductors vs Insulators

  • Conductors have very little resistance and allow electricity to pass through it easily.

  • Insulators have a very large electrical resistance and is much more difficult for electricity to pass through it.

Conductors vs Insulators

  • Conductors have very little resistance, and allow electricity to pass through it easily.

  • Insulators have a very large electrical resistance, and is much more difficult for electricity to pass through it.

Example 1: Circuits transform chemical energy into electricity

6. 1 Electrical energy

  • Circuits transform stored chemical energy into electric potential energy

  • Electrons receive potential energy form the battery and move through wires and components of the circuit.

  • Electrons lose some energy when they pass through a load - ie, a light bulb or motor.

  • Components convert electrical energy into other forms of energy like heat, movement, light.

  • Electrons return to the battery and receive more energy before repeating the process over and over.

Example 1: Circuits transform chemical energy into electricity

6. 1 Electrical energy Summary

  • Circuits are closed paths of electron movement

  • Circuits transform energy - Stored chemical to electrical to Kinetic, heat, light

  • Energy transformations occur when current passes through a load - ie, a light bulb or motor.

  • Current is speed of energy movement through a circuit.

  • Circuit can have high energy but low current, ie electrons move slowly.

Circuits Learning Intention

  • At the end of this lesson you will understand components within a circuit by investigating simple circuits.

Success Criteria:

  • Draw simple electrical circuits

  • Construct a variety of circuits with a battery pack, globe and switch

  • Explain why a complete or a closed circuit is required to carry electrical current

Engage

  • What is this a diagram of? (Image of a circuit diagram)

Circuit Building Theory

  • Diagrams of electric circuits need to be drawn so that people all over the world can read them.

  • Use straight lines for connecting leads and symbols for other parts of circuits.

Circuit Building Practical

  • Apparatus: Battery, switches, wires, light globes.

  • Method: Design, construct and draw a circuit diagram of each circuit described in the “design briefs” below.

  • After you have constructed the circuit and drawn the circuit diagram, call your teacher over to check it and to get it signed.

Circuit Building - Practice

  • Can you think critically and creatively to build and draw simple circuits?

Making Electric Circuits

  • Good Science p 106-107 → Read

  • Cornell Notes

  • Complete Checkpoint 6.4

Extension: Shedding Light

  • Shedding Light on Electricity S01 E02 Electric Circuits

Exit Ticket

  • Scientists use models to help them understand what is going on.

  • An analogy is a model that compares something that is difficult to understand with something that is easy to understand.

  • For example, the structure of the atom is sometimes compared with the structure of the solar system.

  • In this analogy, the Sun represents the nucleus of the atom, and the planets (which are tiny compared with the Sun) represent the electrons.

Exit Ticket

  • Analogy 1- Electrical Circuit

  • Describe how a simple electric circuit can be compared with the ‘water circuit’ that runs a decorative water wheel in a garden pond. What do they have in common? In what way is the analogy not perfect?

Current, Voltage and Resistance Learning Intention

  • At the end of this lesson you will understand voltage, current and resistance within a circuit.

Success Criteria:

  • Describe what electrical current, voltage and resistance are and state their units

  • Use symbols to represent the arrangement of components in circuit diagrams

Engage

(Empty Slide)

Note Taking Circuits

(Empty Slide)

Energy in Circuits

  • Read Good Science p 102-103

  • Take Cornell style notes

  • Complete the Summary later- remember the forgetting curve!

Energy in Circuits

  • Complete Checkpoint 6.2

STILE

1. 1 Lesson: Current, voltage and resistance

  • Your learning goals…

    • Describe what electrical current, voltage and resistance are

STILE

How Electrons
(Empty Slide)

Energy in Circuits

  • Complete Portal Checkpoint 1 - Electrical Circuit Components

Exit Ticket

  • Analogy 2- Current, Voltage and Resistance What do the pipes, water and sand represent?

Booklet Answers

(Conductivity graph and explanation)
*conductivity
Plot a column graph to compare the conductivity of each of the materials.

(Graph)

Explain why it is more appropriate to present this data using a column graph than a line graph.
*There is no continuous variation in the independent variable along the horizontal axis. Thus a line
graph is inappropriate. The column graph is used to visually compare the relative conductivities of the
selection of materials.

Even though silver and copper provide better conductivity, most high-voltage wires are made of aluminium
(and steel). Suggest a reason for this.
*Aluminium is cheaper than copper or silver for long-distance high-voltage wires.

Analogy Answers

  • Both have particles flowing around them. Electrons flow around the electric circuit while molecules of water flow around the water circuit.

  • Both have wires or pipes connecting all their components.

  • Both have a switch or tap to turn the flow on or off.

  • Both need an energy source to operate. The electric circuit needs a battery while the water needs a pump.

  • Both have an energy user. The electric circuit uses a light globe, while most of the energy of the water is ‘used’ in the water wheel itself.

Analogy Answers

  • Voltage (V) is like the water pressure in the hose. It pushes the water (electricity) through the hose (circuit). Higher voltage means more pressure, pushing the water harder.

  • Current (I) is like the flow of water through the hose. It measures how much water (electricity) is moving through the hose (circuit) at a given time. More current means more water flowing.

  • Resistance (R) is like the size of the hose. A narrow hose (high resistance) makes it harder for water to flow through, while a wide hose (low resistance) makes it easier. Higher resistance means less water (electricity) can flow through.