Separate communication, heating and control jobs
Broadcast → radio; oven or satellite → microwaves; remote → infrared; optical fibre → light.
Continue where you stopped
The core idea
Wave · Lesson 3 of 4 · about 25–35 min
What you need to understand
Broadcast → radio; oven or satellite → microwaves; remote → infrared; optical fibre → light.
Definitions
- electromagnetic wave
- a wave that can transfer energy through empty spaceFor example: Radio waves, light and X-rays are electromagnetic waves.
Key idea
- LookA broadcaster sends a television programme, an oven heats food, a handheld remote changes a channel, and a fibre link carries data. Name the prescribed wave for each job.
- ThinkBroadcast → radio; oven or satellite → microwaves; remote → infrared; optical fibre → light.
- DoClassify a familiar broadcasting, heating, satellite, remote-control or fibre context by its prescribed wave association.
Explanation
Use four short associations: radio waves for radio and television broadcasting; microwaves for ovens and satellite communication; infrared for remote controls; and light for optical-fibre telecommunication.
Read the job before choosing. A broadcast aerial points to radio waves, while a satellite link points to microwaves. A handheld controller points to infrared, while pulses travelling through an optical fibre point to light.
Pause and say it: Broadcast → radio; oven or satellite → microwaves; remote → infrared; optical fibre → light.
Common mistake
Tempting wrong idea: Microwaves are used for every communication context, including broadcasting.
Why it fails: Different communication jobs use different waves. Broadcasting uses radio waves, satellite communication uses microwaves, remote controls use infrared and optical fibres carry light. Naming microwaves for all of them loses those associations.
Use this instead: Radio waves are used for broadcasting; microwaves are used for oven heating and satellite communication.
Practical work
What to show: Classify a familiar broadcasting, heating, satellite, remote-control or fibre context by its prescribed wave association.
Before you finish: Do not swap microwave oven heating with light in optical-fibre telecommunication.
Practical link: The topic investigation is taught in “Measure a wave correctly”.
6. Worked examples
Modelled example 1
Choose waves for four familiar devices
Problem
A broadcaster sends a television programme, an oven heats food, a handheld remote changes a channel, and a fibre link carries data. Name the prescribed wave for each job.
Study the worked solution
Read each job before naming a wave
Method
Classify broadcast, oven, remote and optical-fibre contexts separately.
Reason
The devices use different prescribed associations even when several carry information.
Working
broadcast → radio waves; oven → microwaves; remote → infrared; optical fibre → light
Guided practice 2
Match changed wording to the same uses
Problem
Match each context to radio waves, microwaves, infrared or light: a local station transmits programmes; a dish exchanges a signal with a satellite; a controller sends a command to a television; pulses travel inside a glass fibre.
Write four pairings
Hints
Hint 1: separate the communication contexts
Broadcasting and satellite communication are different named uses.
Hint 2: separate controller from fibre
Remote controls use infrared; optical fibres carry light.
View solution step by step
Match from the job
Method
Separate the broadcast, satellite, controller and fibre contexts.
Reason
Each context names one of the four prescribed application associations.
Working
station broadcast → radio waves; satellite dish → microwaves; handheld controller → infrared; glass fibre → light
Common misconception 3
Correct two tempting swaps
Learner response
“Broadcasting uses microwaves, and a remote control sends visible light.” Correct both pairings.
Replace each wave
View solution step by step
Use the prescribed associations
Method
Replace each swapped wave with the wave named for that application.
Working
Broadcasting uses radio waves. A remote control uses infrared.
Reason
Microwaves are named for satellite communication and ovens; light is named for optical fibres.
Challenge 4
Plan a media-room setup
Problem
A media room receives an overseas feed through a satellite dish, heats lunch in an oven, and sends data through a glass fibre. Name the prescribed wave for each use.
Classify all three jobs independently
Hints
Hint 1: separate the two communication paths
A satellite dish and an optical fibre use different named associations.
Hint 2: retrieve the three pairings
Satellite and oven contexts use microwaves; optical fibres use light.
View solution step by step
Retrieve each named association
Method
Match each stated device to its prescribed wave association.
Working
satellite dish → microwaves; oven → microwaves; optical fibre → light
Reason
Two contexts can share one prescribed wave, but that does not make every communication use a microwave use.
Guided practice
Try it with support
Choose the prescribed wave for each use: a radio broadcast, satellite communication, a remote control and an optical fibre.
- Separate broadcast from satellite communication, then separate the handheld controller from the fibre link.
Check the guided answer
Answer: Radio waves are used for broadcasting, microwaves for satellite communication, infrared for remote controls and light for optical fibres.
Check: The communication context distinguishes radio waves, microwaves, infrared and light.
Practise and continue
Practise this
A kitchen appliance heats food without a flame, while a glass fibre carries internet data as pulses. Name the prescribed wave in each changed context.
Need a hint?
- Treat heating and fibre communication as two separate jobs.
Check your answer
Answer: The heating appliance uses microwaves; the optical fibre carries light.
Check: Do not swap microwave oven heating with light in optical-fibre telecommunication.
Think like a scientist
A learner chooses infrared for every communication device. Use a remote control, a satellite link and an optical fibre to explain why that rule fails.
Check the reasoning
Infrared is used for the remote control, microwaves for the satellite link and light for the optical fibre.
Remember: Devices that carry information do not all use the same electromagnetic wave.
One-minute check
- Hide the page and explain separate communication, heating and control jobs in your own words.
- Give a new example that is different from the worked example.
- Correct this common mistake: “Microwaves are used for every communication context, including broadcasting.”