DuncanrigSecondary School
East Kilbride
S3 Physics Elective
Telecommunications
Pupil Booklet
- Learning Outcomes
- Homework
- Summary
Page 1
How Confident am I with the Content Statements?
- Circle the symbols to keep a record of your progress.
I am confident that I understand this and I can apply this to problems
I have some understanding but I need to revise this some more
I don’t know this or I need help because I don’t understand it
- You can use this to help you pick the areas of the unit that need the most revision.
- As you revise your class work you will be able to circle more and more smiley faces.
- If that does not help then you should ask your teacher!
Content Statements / Can you do this? / Comments
Radio
1 State that the main parts of a radio receiver are: Aerial, tuner, decoder, amplifier, loudspeaker, electricity supply; and identify these parts on a block diagram. /
2Describe in a radio receiver the function of: Aerial, tuner, decoders, amplifier, loudspeaker, electricity supply. /
3 Describe the general principle of radio transmission in terms of transmitter, carrier wave, amplitude modulation, receiver. /
4 Identify from drawings the various wave forms associated with radio transmission. /
Analogue and Digital Radio
1 Be able to identify analogue and digital signals from wave forms. /
2 Calculate the binary equivalent of a decimal number in the range 0 to 12. /
3 State some of the advantages that digital radio has over analogue radio. /
Television
1 State that television transmission is similar in principle to radio transmission. /
2 Describe how a moving picture is seen on a television screen in terms of: image retention. /
3 State that mixing red, green and blue lights produces all colours seen on a colour television screen. /
4 Describe the effect of colour mixing lights (red, green and blue). /
5 Compare the properties of different types of modern television. /
Diffraction and Reflection
1 State that diffraction is the bending of waves passing through a gap or round the edge of an obstacle. /
2 Explain in terms of diffraction how wavelength affects radio and television reception. /
3 State that light can be reflected /
4 Describe the direction of the reflected light ray from a plane “mirror”. /
5 State what is meant by an optical fibre. /
6 State that electrical cables and optical fibres are used in some telecommunication systems. /
7 Describe one practical example of telecommunication which uses optical fibres. /
8 State that signals travel along optical fibres at very high speed /
Curved Reflectors and Satellites
1State that curved reflectors on certain aerials or receivers make the received signal stronger. /
2Explain why curved reflectors on certain aerials or receivers make the signal stronger. /
3 Give examples of where curved reflectors are used. /
4State that the period of satellite orbit depends on its height above the Earth. /
5State that a geostationary satellite stays above the same point on the Earth’s surface. /
6Describe the principle of transmission and reception of satellite television broadcasting using geostationary satellites and dish aerials. /
7Describe the principle of intercontinental telecommunication using a geostationary satellite and ground stations. /
Modern Communication Methods
1 State that the internet is the underlying telecommunications network that makes the world wide web possible. /
2 Name applications that use the internet. /
3 State that the internet uses a mixture of electrical cables, optical fibres, radio waves and satellite links to send information. /
4 State that the telephone is an example of long range communication between transmitter and receiver. /
5 State the energy changes
a) In a microphone (sound electrical)
b) In a loud speaker (electrical sound). /
6 State that the mouthpiece of a telephone (transmitter) contains a microphone and the earpiece (receiver) contains an earphone (loudspeaker). /
7 State that an electrical signal is transmitted along a wire at a speed much greater than the speed of sound (almost 300 000 000 m/s). /
8 State that mobile phones use microwaves to transmit information. /
9 State that
a)mobile phone networks use “cells” and at the centre of each cell is a base station
b)the base station sends and receives calls from your phone. /
10 Make a reasoned argument whether mobile phones are a danger to health or not. /
Wave Properties
1 State that waves are one way of transmitting signals. /
2 Use the following terms correctly in context: wave, frequency, wavelength, speed, energy (transfer), amplitude. /
3 Describe, with examples, how the following terms relate to sound: frequency and amplitude. /
4 Carry out calculations involving the relationship between distance, time and speed in problems on sound, light, radio, TV and microwaves. /
5 Carry out calculations involving the relationship between speed, wavelength and frequency for sound, light, microwaves, television and radio waves. /
6 Note the equivalence of f and d/t. /
Elective Homework – Getting Started
Success involves doing many kinds of problems which help improve your knowledge and understanding of the ideas in the course and your ability to solve problems. To get started we will look at a general method for tackling problems.
General Method for Solving Problems.
Any numerical problem in Physics can be solved using the following steps:
- Read the question carefully.
- Find out exactly what is being asked.
- Extract the key data.
- Select the correct equation.
- Substitute the data into the equation and find the missing variable.
- Give the answer and correct unit.
Example
How far does a cyclist travel in 26 seconds if she is travelling at a constant speed of 8 metres per second?
Solution
Read the question carefully
Find out exactly what is being asked Distance (how far)
Extract the key data time = 26 seconds
speed = 8 metres per second
Select the correct equation distance = speed x time
Substitute data into equation d = 8 x 26
Give the answer and correct unit d = 208 m
Usual Layout
d = ?v = 8 m/s
t = 26 s / d = v x t
= 8 x 26
= 208 m
All numerical questions in the following homework exercises should be carried out in this way. No marks will be awarded for an answer given without the working being shown.
Page 1
Homework Exercise 1 – Radio, Analogue and Digital.
You will find help with this exercise on pages 22 and 23.
- (a) Copy the table below and fill in the correct definition for each item. (6)
Part / Function
Aerial
Tuner
Decoder
Amplifier
Loudspeaker
Electricity supply
(b) Draw a block diagram to show how the parts of a radio receiver are connected together. (3)
- (a) Explain what is meant by an amplitude modulated wave.(2)
(b) Draw an amplitude modulated wave.(1)
(c) The radio frequency of the modulated wave is called the carrier wave. Why do you think it gets this name? (1)
- Which of the following is an analogue signal and which is digital?
(1)
Signal A / Signal B- Convert the decimal number 7 into binary.(1)
Total (15)
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Homework Exercise 1 – Radio, Analogue and Digital.
Put your answers here
Page 1
Homework Exercise 2 – Television.
You will find help with this exercise on pages 23 and 24.
- (a) Explain what is meant by persistence of vision.(1)
(b) How does persistence of vision help create a moving picture? (1)
- A colour television produces millions of colours on the screen.
(a)Name the colours that are used to produce all the colours seen on a TV screen. (1)
(b)How are these colours used to produce the millions of colours seen on a TV screen? (1)
- Copy and complete the diagram below to show how red, blue and green light mix. You do not need to use colour, labels will do. (2)
Total(6)
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Homework Exercise 2 – Television.
Put your answers here.
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Homework Exercise 3 - Diffraction and Reflection.
You will find help with this exercise on pages 24and 25.
- What word describes the bending of waves around the edge of a barrier? (1)
- Copy and complete the diagrams below showing what happens to the waves as they pass round the edge of the barrier. (2)
long wavelengths / short wavelengths
- Copy and complete the diagram below showing the path of the ray of light. Indicate any important information required about the angles in the diagram. (2)
- (a) What is an optical fibre?(1)
PTO
(b) Copy and complete the diagram to show the path taken by the ray of light passing through an optical fibre. (1)
- (a) Name a communication system that uses optical fibres to transmit information. (1)
(b) In what form is information passed along an optical fibre? (1)
- An optical fibre is used to carry a telephone message from the USA to Scotland. It travels 5000km. The light signal travels at a speed of 2 x 108 m/s. How long will this take? (2)
Total (11)
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Homework Exercise 3 - Diffraction and Reflection.
Put your answers here.
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Homework Exercise 4 – Curved Reflectors and Satellites.
You will find help with this exercise on pages 26 and 27.
- Aerials picking up signals from a long distance away often have curved reflectors attached to them.
(a)What is the purpose of the curved reflector?(1)
(b)By use of a diagram show how it does this.(1)
- The period of a geostationary satellite is 24 hours.
(a)Explain what is meant by a geostationary satellite.(1)
(b)What is meant by the word period?(1)
(c)How is a satellite’s period affected by it’s height above the Earth? (1)
- Copy the diagram below to show how a curved reflector helps transmit a parallel beam of waves. (2)
Total(7)
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Homework Exercise 4 – Curved Reflectors and Satellites.
Put your answers here.
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Homework Exercise 5 – Modern Communication Methods.
You will find help with this exercise on page 27.
- What name do we give to all the world’s linked up computers?
(1)
- Name four different ways in which links are made between these computers. (2)
- What is the job of a router?(1)
- Copy the diagram of a telephone handset and label the parts given below.
transmitter, receiver, loudspeaker, microphone(2)
- What are the main energy changes in:
(a)The loudspeaker?(1)
(b)The microphone?(1)
- Which member of the electromagnetic spectrum is used to send information across the mobile phone network? (1)
Total(9)
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Homework Exercise 5 – Modern Communication Methods.
Put your answers here.
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Homework Exercise 6 – Wave Properties 1.
You will find help with this exercise on pages 28 and 29.
- Copy and complete the table below.(6)
Wave Term / Symbol / Unit / Definition
frequency
wavelength
speed
- The following questions refer to the diagram below:
(a)Calculate the wavelength of the waves shown.(1)
(b)If these waves were produced in 6 seconds, what is their frequency? (1)
(c)What is the amplitude of these waves?(1)
(d)Use the wave equation to calculate the speed of these waves. (2)
- Look at this diagram of a sound signal displayed on an oscilloscope. Describe what would happen to its frequency and amplitude in each of the following cases.
(a)The volume of the sound is increased. (1)
(b)The pitch is increased and he volume stays the same. (1)
(c)The pitch and the volume are decreased. (1)
Total(14)
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Homework Exercise 6 – Wave Properties 1.
Put your answers here.
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Homework Exercise 7 – Wave Properties 2.
You will find help with this exercise on pages 28 and 29.
- Find the missing variable in each row of the table. You must show all your working for each missing variable. (4)
Speed / Distance / Time
10 m/s / 100 m
3000 m / 150 s
1.2 m/s / 30 s
- A person at the mouth of a cave shouts, and hears an echo from the back wall of the cave. Using a stopwatch, she times 1 second between shouting and hearing the echo. Calculate how far away the back wall of the cave is. Take the speed of sound to be 340 m/s. (3)
- A wave of frequency 8 Hz has a wavespeed of 16 m/s.
What is its wavelength?(2)
- A wave generator at a swimming pool creates waves which have a wavelength of 2m. If the speed of the waves is 1.2m/s what is their frequency? (2)
- The navy use long wavelength radio waves for telecommunications.
Calculate the frequency of a radio wave with a wavelength of 8.6 km used by the navy to communicate at sea. (2)
Total(13)
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Homework Exercise 7 – Wave Properties 2.
Put your answers here.
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Telecommunications - Summary.
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Telecommunications - Summary.
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Telecommunications - Summary.
Diffraction of long wavelengths / Diffraction of short wavelengthsPage 1
Telecommunications - Summary.
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Telecommunications - Summary.
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Telecommunications - Summary.
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Telecommunications - Summary.
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Telecommunications - Summary.
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