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A radio station transmits on 97.4 MHz - Edexcel - GCSE Physics Combined Science - Question 3 - 2020 - Paper 1
Question 3
A radio station transmits on 97.4 MHz. To receive the waves an aerial needs a length equal to half the wavelength of the radio waves being transmitted. Calculate t... show full transcript
Worked Solution & Example Answer:A radio station transmits on 97.4 MHz - Edexcel - GCSE Physics Combined Science - Question 3 - 2020 - Paper 1
Step 1
Calculate the length of the aerial needed
Answer
To find the length of the aerial, we first need to calculate the wavelength ( \lambda) of the radio waves transmitted by the radio station.
Given that frequency (f) = 97.4 MHz = 97.4 x 10^6 Hz,
and speed (v) = 3.00 x 10^8 m/s,
We can use the formula:
Substituting the values in, we have:
Since the length of the aerial is equal to half of the wavelength:
Thus, the length of the aerial needed is 1.54 m.
Step 2
Describe how the student should measure the angle of refraction
Answer
To measure the angle of refraction using the apparatus in Figure 3, the student should follow these steps:
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Trace the ray: Start by tracing the path of the ray entering into and out of the glass block on either side.
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Remove the block: Carefully take away the glass block to expose the traced lines.
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Identify entry and exit points: Clearly mark the entry and exit points of the ray for accuracy.
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Use a protractor: Employ a protractor to measure the angle between the refracted ray and the normal at the point where it exits the glass block.
This method will accurately allow the student to determine the angle of refraction as the light passes through different media.