Practical Electricity for Secondary 2

Practical Electricity for Secondary 2

Poll

What is the average electricity bill for your household per month?

• Less than $100

• Between $100 to $200

• Between $200 to $300

• More than $300

Poll

I have _____ electrical appliances in my home.

• less than 20

• between 20 to 40

• between 40 to 60

• between 60 to 80

• more than 80

Open Ended

Based on

Cost of electricity = kW x time in hour x cost per unit

Which is the electrical appliance may cost the most to use?

​​What Is The Open Electricity Market (OEM)?

The Open Electricity Market (OEM) is part of EMA's effort to liberalise the electricity market, allowing residential households in Singapore to buy electricity from retailers other than SP Group.

Multiple Choice

Who Discovered Electricity?

• Thomas Edison

• Benjamin Franklin

• Michael Faraday

• Alessandro Voltra

​​Benjamin Franklin

​Benjamin Franklin conducted early experiments with lightning and electricity.

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In 1752, Benjamin Franklin ran his famous kite experiment that sparked the discovery of electricity. As a prominent American scientist and one of America's founding fathers, Franklin tied a key to a kite string during a thunderstorm and proved that static electricity and lightning were one and the same thing.​

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​https://www.youtube.com/watch?v=f0oc4gUCOQI

​"The SHOCKING Truth About Ben Franklin and the Kite"

​​What Is Voltage?

Multiple Choice

What is the operating voltage (at the socket point ) in SIngapore?

• 110 V

• 160 V

• 230 V

• 280 V

​Is Electricity Used in the Human Body?

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Your brain dispatches millions of electrical signals along the nerves in your central nervous system. These nerves connect with your muscles and provide the power to complete an action or movement. These electrical signals enable you to brush your teeth, eat a meal and run off extra calories.

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Multiple Choice

A plug connected to a table lamp contains a 3 A fuse.

Why is the fuse needed?

• To reduce voltage across the lamp

• To protect the wiring from excessive current flow

• To increase the resistance of the circuit

• To make it easier for the current to flow

Multiple Choice

An appliance uses 3.5 A of current. To protect it, we should use a fuse of ___ A.

• 2 A

• 3 A

• 5 A

• 10 A

​What Happens When You Get Electrocuted?

Why don't birds get electrocuted on power lines?

https://www.youtube.com/watch?v=rtnmCf2QFTc

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​"Why don't birds get electrocuted on power lines?"

Open Ended

Why does water lower our body resistance?

Why does water lower our body resistance?

​https://www.youtube.com/watch?v=o1vpjqYddk0

​Safety Heroes – Electricity and water

Multiple Choice

Which of the following is not a consequence of wet electrical appliances?

• causing blackout as they trip the circuit breaker

• causing short circuits, which may result in high current

• electrocuting people when being touched

• making the fuse burn out, which can cause fire

Multiple Choice

Which one is a safe practice in using electricity?

• Pulling an electrical plug at the cord

• Unplugging an electrical appliance from the socket before cleaning it

• Charging a handphone in the bathroom

• Overloading a power socket

Fill in the Blanks

​Wiring - LIVE, NEUTRAL, EARTH

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​How do you wire a three pin plug?

​https://www.youtube.com/watch?v=COWlYUvzgZI

​How to change a Plug UK 3-pin - Rewire & Earthing - Easy DIY by Warren Nash

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• A

• B

• C

• D

​Electrical Hazards - OVERLOADING

​https://www.youtube.com/watch?v=JcJAGhEuvo0

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​Overloading of a multi plug resulting in overheating and fire

Open Ended

How do overloading cause what we saw in the video?

​Electrical Hazard - SHORT CIRCUIT

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Open Ended

How can you use electricity in a safe and responsible manner?