Photo AI
A radio station transmits on 97.4 MHz - Edexcel - GCSE Physics - Question 5 - 2020 - Paper 1
Question 5
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 - Question 5 - 2020 - Paper 1
Step 1
Calculate the length of aerial needed:
Answer
-
Recall the Relationship: The wavelength ( \lambda ) can be calculated using the formula:
[ \lambda = \frac{v}{f} ]
where ( v ) is the speed of the waves and ( f ) is the frequency. -
Convert the Frequency:
The frequency given is 97.4 MHz. Convert this to Hz:
[ 97.4 \text{ MHz} = 97.4 \times 10^6 \text{ Hz} ] -
Substitute Values:
Now substitute the values into the formula:
[ \lambda = \frac{3.00 \times 10^8 , \text{m/s}}{97.4 \times 10^6 \text{ Hz}} ] -
Calculate Wavelength:
Performing the calculation yields:\n [ \lambda \approx 3.08 , \text{m} ] -
Length of Aerial:
Since the aerial needs to be half the wavelength:
[ \text{Length of aerial} = \frac{\lambda}{2} = \frac{3.08}{2} = 1.54 , \text{m} ]
Step 2
Describe how the student should measure the angle of refraction:
Answer
-
Trace the Ray: The student should start by tracing the ray of light entering the glass block and marking where it exits.
-
Remove the Block: While keeping the marked entry and exit points, the glass block should be removed to clearly see the line of the ray.
-
Use a Protractor: The student should then place a protractor at the point of entry to measure the angle between the drawn ray (the refracted ray) and the normal line (a perpendicular line at the interface of the glass and air).
-
Record the Measurement: Finally, the angle between the refracted ray and the normal should be recorded as the angle of refraction.