Electricity and Ohm's Law

All matter is made up of particles.

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Electrical energy is energy produced by the movement of certain particles.

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This flow of particles is called electric current.

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​Some text here about the topic of discussion.

​How does electricity travel?

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​Some text here about the topic of discussion.

​ How does Electricity travel?

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​In order to light a light bulb or turn on a computer, we need to produce a continuous electric current.

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An electric circuit is a pathway through which electric current flows.

Multiple Choice

A Circuit is the pathway through which electricity flows.

• True

• False

​Two kinds of metals build up opposite charges.

( - ) Negative

( + ) Positive​

​​Power Source

​A material that allows heat or an electric current to flow through easily.

• Good Conductors (copper/aluminum)

​​ Conductor

​A material through which heat or electricity does not easily flow through.

​​ Insulator

​Circuits deliver electrical energy to a

load, or device, that will use that energy. Loads change electrical energy into some other form of energy. Light bulbs, fans, and buzzers are common loads.

Load​

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​What does a Circuit need to work ?

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​How does electricity travel?

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Match

Match the following

Insulator

power source

conductor

load

Switch

• Insulator

• power source

• conductor

• load

• Switch

You can think of a circuit as a loop. In order for electric current to flow through the loop, the loop must not contain breaks. In other words, the circuit must be closed.

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​Some text here about the topic of discussion.

​How does energy flow through a circuit?

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​How does electricity travel?

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​How does electricity travel?

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​How does electricity travel?

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​How does electricity travel?

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Multiple Choice

Which Image has an electrical current flowing through (closed Circuit) ?

Multiple Choice

The energy being used is __________ and it is producing _______ energy.

• Electrical energy to sound energy.

• Electrical energy to mechanical energy.

• Sound energy to electrical energy.

• Sound energy to light energy.

Multiple Choice

The energy being used is __________ and it is producing _______ energy.

• Electrical energy to sound energy.

• Electrical energy to mechanical energy.

• Electrical energy to Light energy.

• Electrical energy to light and thermal energy.

Poll

How dependent are we on electricity?

• Extremely dependent.

• Sort of dependent.

• I can live without it.

ohms law

Multiple Choice

Fill in the blank:

Ohm’s law explains the relationship between ……………. in a circuit.

• Voltage ,Current and Power

• Voltage ,Current and Resistance

• Voltage and Current

• Only Voltage

Multiple Choice

How can Ohm's law be written?

• R=I/V

• V=I×R

• V=I/R

​How can we describe these?

1. Voltage (v)

2. Current (I)

3. Resistance (R)​

So now let us imagine that you want to install a beautiful waterfall in your garden (also imagine that you are rich enough to have a big garden).

Multiple Choice

What does water need in order for it to flow?

• More of it

• Different temperature

• Ice

• A high and low part

Multiple Choice

If you want water to go from low potential energy to high you would need to add...

• A pump

• a boat

• a diving board

• A ramp

Let us connect up some wires to the bulb to try and make it light up. But sadly, we find that the bulb does not light up. We can see that the wire has electrons in it, but the bulb does not light up. Why is this ?

The reason that the bulb does not light up is that there is no “flow” of electrons. Electrons need to move in one direction to make the light bulb light up. If they just ‘hang around’ without moving in one direction, nothing happens.

Open Ended

What could the cause of the potential difference in our circuit be? (like the water pump)

The blue dots are electrons the red dots are empty places for the electrons

Multiple Choice

What is the difference between a 1.5V and a 9v battery?

• 1.5 has a larger potential difference

• 9 has a larger potential difference

• The number only describes the size of the battery

• The number only describes how long the battery will last

​Voltage is like Pressure

​Current is measured in Amperes

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Commonly referred to as "Amps"

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​The symbol for current is I

​I = V/R

​Current is like "Flowrate"

​A flow of electrons

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​Which has more current?

Multiple Choice

What causes a light bulb to be brighter

• Current

• Voltage

• Resistance

​What is Resistance?

​Resistance is the LOAD

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Why does a light bulb light up?​

​The energy of the flow rate (I) caused by the pressure (v) is used to turn the turbine (R) to get some work done.