MYP Physics · 12 · data analysis
Wavelengths used by wireless links
Electromagnetic spectrum · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- routine
- Marks
- 6
- Topics
- 2
- Answer
- Complete
A school compares three electromagnetic communication links. Use a wave speed of 3.00 × 10⁸ m s⁻¹ in air.
| Link | Frequency |
|---|---|
| Campus radio | 100 MHz |
| Wi-Fi | 2.40 GHz |
| Fibre laser | 200 THz |
- a
Calculate Calculate the wavelength of the 2.40 GHz Wi-Fi signal.
3 marks - b
Compare Identify which link has the shortest wavelength and justify your answer.
2 marks - c
State State one limitation of treating all three links as travelling at exactly the vacuum speed.
1 mark
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a
Calculate Calculate the wavelength of the 2.40 GHz Wi-Fi signal.
Read the data before explaining it. Quote the relevant values or trend, show the comparison or calculation, and then connect that numerical evidence to the physical conclusion—including uncertainty or anomalies when they matter.
- 1
Converts 2.40 GHz to 2.40 × 10⁹ Hz.
- 2
Uses λ = c ÷ f.
- 3
Obtains λ = 0.125 m.
b
Compare Identify which link has the shortest wavelength and justify your answer.
Read the data before explaining it. Quote the relevant values or trend, show the comparison or calculation, and then connect that numerical evidence to the physical conclusion—including uncertainty or anomalies when they matter.
- 1
Identifies the fibre laser.
- 2
Explains that it has the greatest frequency and therefore the shortest wavelength at the same wave speed.
c
State State one limitation of treating all three links as travelling at exactly the vacuum speed.
Read the data before explaining it. Quote the relevant values or trend, show the comparison or calculation, and then connect that numerical evidence to the physical conclusion—including uncertainty or anomalies when they matter.
- 1
States that waves travel more slowly in materials such as glass fibre, or that air speed is only approximately the vacuum value.
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