Signal weakening over distance in cables
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. What happens to a signal as it travels further along a cable?
2. Why do copper network cables like Ethernet have a maximum length?
3. Which cable can carry a signal much further before it becomes too weak?
4. What does a repeater do?
5. A school needs to link two buildings 500 metres apart. Which is the better choice?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1attenuation | AA device that boosts a weakening signal so it can travel further | |
| 2repeater | BFibre cable: many kilometres | |
| 3Copper cables have a length limit because the signal fades over distance | CA repeater does not shorten the cable. It boosts the weakened signal so it can keep travelling. | |
| 4Fibre cables lose less signal, so they can carry data much further than copper | DSignals do weaken. Over 300 m, copper attenuation makes the signal too weak, so a repeater or fibre is needed. | |
| 5A 300 m copper cable run works fine with no repeater because signals never weaken. | EEthernet cable: maximum 100 m | |
| 6A repeater makes the cable shorter so the signal does not weaken. | FThe weakening of a signal as it travels along a cable |
C
Definitions
attenuation
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
___________ = weaker signal over distance
2.
IF length > max THEN ADD ________
3.
IF cableLength _ copperLimit THEN
4.
copperLimit _ fibreLimit
5.
strength ← strength _ loss
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
copper_limit ← 100 kilometres
B
fibre_limit ← 40000 metres
C
DISPLAY copper_limit
Question 2
A
attenuation = signal grows
B
cause ← distance travelled
C
fix ← add a repeater
Question 3
A
signal ← 100
B
distance ← 90
C
loss ← distance * 1
D
signal ← signal + loss
E
DISPLAY signal
Question 4
A
IF cable = fibre THEN
B
limit ← 50 metres
C
ELSE
D
limit ← 100 metres
E
ENDIF
Question 5
A
length ← 150
B
IF length > 100 THEN
C
REMOVE repeater
D
ENDIF
Answer Key
Signal weakening over distance in cables
Section A: Quick Questions
Q1
A — It gets weaker
Q2
A — The signal weakens over distance
Q3
B — Fibre optic cable
Q4
B — Boosts a weak signal so it can travel further
Q5
A — Fibre cable, or copper with repeaters
Section B: Match the Pairs
Q1
attenuation → The weakening of a signal as it travels along a cable
Q2
repeater → A device that boosts a weakening signal so it can travel further
Q3
Copper cables have a length limit because the signal fades over distance → Ethernet cable: maximum 100 m
Q4
Fibre cables lose less signal, so they can carry data much further than copper → Fibre cable: many kilometres
Q5
A 300 m copper cable run works fine with no repeater because signals never weaken. → Signals do weaken. Over 300 m, copper attenuation makes the signal too weak, so a repeater or fibre is needed.
Q6
A repeater makes the cable shorter so the signal does not weaken. → A repeater does not shorten the cable. It boosts the weakened signal so it can keep travelling.
Section C: Definitions
Q1
attenuation — The weakening of a signal as it travels along a cable. Copper cables have a length limit because of it, while fibre can go much further. Repeaters boost the signal.Section D: Fill in the Blanks
Q1
attenuation = weaker signal over distanceQ2
IF length > max THEN ADD repeaterQ3
IF cableLength > copperLimit THENQ4
copperLimit < fibreLimitQ5
strength ← strength - lossSection E: Spot the Error
Q1
A — Copper cables lose signal strength quickly, so their limit is only about 100 metres, not 100 kilometres. It should be copper_limit ← 100 metres.
Q2
A — Attenuation is the signal getting weaker as it travels along a cable. It does not grow. It should be attenuation = signal weakens.
Q3
D — Attenuation means the signal gets weaker over distance, so the loss must be subtracted. It should be signal ← signal - loss.
Q4
B — Fibre has a much longer limit than copper. The fibre branch should use a large limit such as 40000 metres. A tiny limit like 50 metres is shorter than the copper limit.
Q5
C — When a copper cable is longer than its limit, a repeater is added to boost the signal. Removing one would leave the signal weaker. It should be ADD repeater.