Physics C.R.O
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I find myself having difficulties interpreting C.R.O graphs and drawing it out. Our teacher didn't really teach us that. So yea, hope you guys can clarify some of my doubts.
Here's one question from my assessment book:
With the Y-plates switched off the time base is set to 2ms cm-1. Draw the horizontal line in the screen below if the frequency of the time-base is 50 Hz.
Period : 1/50 = 0.02
0.02/0.002 = 10
Does the 10 units refer to the number of lines counted individually to the left and right or is it like 5 units to left and units to the right(with respect to the dot in the middle)?
And 1 square represents 1 cm. I do not get why my answer draws the line on 2.5 lines to the left and right individually and say it is 10cm. Someone, please help.
2. If the X-plates are switched off and Y-plates are connected to a 240 V A.C source ad the Y-plates are set to a scale of 60 V/cm,
Do we draw something like 4cm to the top(with respect to spot in the middle) and 4cm to the bottom? I do think this is correct, but again, my book draws it about 4.5 - 5 units to the top and bottom.
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Yea, here's one question again.
The Y-plates of a c.r.o is connected to a microphone, as shown in diagram below. When the gun is fired, the c.r.o registers a wave. A second set of waves are registered when the sound reflects off the wave and travels back to the microphone. The time-base is set at 50 ms cm-1. Calculate the distance X (between microphone and the wall)
My book takes 330 X 100ms = 33m (consider only half the time)
Don't understand why it is 100 ms. How about the time take for echo to travel?
*by the way, in c.r.o readings, is the intervals between the 2 "lightning bolts" the distance or do we just take the length the lightning bolt occupies in the boxes?
Thanks all!
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Originally posted by anpanman:
I find myself having difficulties interpreting C.R.O graphs and drawing it out. Our teacher didn't really teach us that. So yea, hope you guys can clarify some of my doubts.
Here's one question from my assessment book:
With the Y-plates switched off the time base is set to 2ms cm-1. Draw the horizontal line in the screen below if the frequency of the time-base is 50 Hz.
Period : 1/50 = 0.02
0.02/0.002 = 10
Does the 10 units refer to the number of lines counted individually to the left and right or is it like 5 units to left and units to the right(with respect to the dot in the middle)?
And 1 square represents 1 cm. I do not get why my answer draws the line on 2.5 lines to the left and right individually and say it is 10cm. Someone, please help.
2. If the X-plates are switched off and Y-plates are connected to a 240 V A.C source ad the Y-plates are set to a scale of 60 V/cm,
Do we draw something like 4cm to the top(with respect to spot in the middle) and 4cm to the bottom? I do think this is correct, but again, my book draws it about 4.5 - 5 units to the top and bottom.
This is a topic that uses a lot of pictures and drawing and sketching.
I need to see your answer and the assessment book's answer. I have a hunch why you are confused, but without seeing the picture, I cannot confirm. And the explanation will and might be confusing.
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Originally posted by anpanman:
Yea, here's one question again.
The Y-plates of a c.r.o is connected to a microphone, as shown in diagram below. When the gun is fired, the c.r.o registers a wave. A second set of waves are registered when the sound reflects off the wave and travels back to the microphone. The time-base is set at 50 ms cm-1. Calculate the distance X (between microphone and the wall)
My book takes 330 X 100ms = 33m (consider only half the time)
Don't understand why it is 100 ms. How about the time take for echo to travel?
*by the way, in c.r.o readings, is the intervals between the 2 "lightning bolts" the distance or do we just take the length the lightning bolt occupies in the boxes?
Thanks all!
You can see that the total time taken for the wave to reach the wall AND then come back is 4 squares * 50 ms = 200 ms. 200ms is twice the time the wave requires for a one-way trip therefore the distance for a one way trip is 100 ms * speed of sound = 33m
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Hi Guys! Sorry for the delay in my reply. Will post the pictures up ASAP because I have tonnes of homework to complete and tests to revise for. So perhaps tomorrow... and thanks crimson soldier for the help given still. (: