A-LevelPhysicsWaves9702/12 · Oct/Nov 2020 · Q281 Mark
A transmitting mast sends out microwaves of wavelength 1.5 cm and radio waves of wavelength 1.5 km. [Figure 28.1] A receiving aerial behind a mountain can detect the radio waves but not the microwaves. What is the reason for this?
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
AThe radio waves are coherent but the microwaves are not.
BThe radio waves are diffracted around the mountain but the microwaves are not.
CThe radio waves are reflected by the mountain but the microwaves are not.
DThe radio waves travel at the speed of light but the microwaves do not.
✓ Correct answer
B: The radio waves are diffracted around the mountain but the microwaves are not.
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