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Which control on the oscilloscope should be used to centre the trace vertically on the screen? Tick (✓) one box - AQA - A-Level Physics - Question 1 - 2022 - Paper 3
Question 1
Which control on the oscilloscope should be used to centre the trace vertically on the screen? Tick (✓) one box. X-shift Y-gain Y-shift When the hammer hits end ... show full transcript
Worked Solution & Example Answer:Which control on the oscilloscope should be used to centre the trace vertically on the screen? Tick (✓) one box - AQA - A-Level Physics - Question 1 - 2022 - Paper 3
Step 1
Step 2
Deduce the speed of sound in the steel rod.
Answer
To deduce the speed of sound, we can use the formula:
ext{speed of sound} = rac{ ext{distance}}{ ext{time}}Given:
- Distance between L and R = 0.870 m
- Time taken for the wave to travel there and back = (6 ext{ major divisions}) imes (0.20 ext{ ms/div}) = 1.2 ext{ ms} = 1.2 imes 10^{-3} ext{ s}
The total distance is twice the length of the rod:
Distance = 2 imes 0.870 = 1.740 m
Thus, we can deduce the speed as follows:
ext{speed of sound} = rac{1.740 ext{ m}}{1.2 imes 10^{-3} ext{ s}} = 1450 ext{ m s}^{-1}Step 3
Explain how using the longer rod affects the waveform displayed.
Answer
Using a steel rod of twice the length will result in a longer delay for the sound wave to travel to end R and back to end L. This increased distance means the waveform will show a greater time interval between the peaks, indicating a longer period for the wave due to the increased path length.
Step 4
Explain any changes needed to get an accurate result for the speed.
Answer
To obtain an accurate result for the speed using the longer rod, the time-base setting on the oscilloscope might need adjustment to accommodate the longer time intervals. Specifically, the time per division should be increased to properly view the waveform cycles. If the same settings are used as with the shorter rod, the waveform may extend beyond the screen, making it difficult to analyze correctly.