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Does anyone know how to do this question? Sorry i don't really understand capacitors with AC voltage supply/
https://isaacphysics.org/questions/c...d-5d7cabf77076
https://isaacphysics.org/questions/c...d-5d7cabf77076
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#2
(Original post by amell1234)
Does anyone know how to do this question? Sorry i don't really understand capacitors with AC voltage supply/
https://isaacphysics.org/questions/c...d-5d7cabf77076
Does anyone know how to do this question? Sorry i don't really understand capacitors with AC voltage supply/
https://isaacphysics.org/questions/c...d-5d7cabf77076
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(Original post by mqb2766)
Half looked at it. As the question is (partially about) capacitors and ac voltage, what do you understand and what is causing problems in the question?
Half looked at it. As the question is (partially about) capacitors and ac voltage, what do you understand and what is causing problems in the question?
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#4
(Original post by amell1234)
Does anyone know how to do this question? Sorry i don't really understand capacitors with AC voltage supply/
https://isaacphysics.org/questions/c...d-5d7cabf77076
Does anyone know how to do this question? Sorry i don't really understand capacitors with AC voltage supply/
https://isaacphysics.org/questions/c...d-5d7cabf77076
Basically, the capacitor charges over the first quarter cycle, then barely discharges over the last 3/4, keeping an essentially constant voltage across R. You need to calculate the average current over that first, quarter cycle, to get the charge that passes, then add that from the constant voltage over the other 3/4 cycle.
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(Original post by RogerOxon)
Try a search - I've seen this question before.
Basically, the capacitor charges over the first quarter cycle, then barely discharges over the last 3/4, keeping an essentially constant voltage across R. You need to calculate the average current over that first, quarter cycle, to get the charge that passes, then add that from the constant voltage over the other 3/4 cycle.
Try a search - I've seen this question before.
Basically, the capacitor charges over the first quarter cycle, then barely discharges over the last 3/4, keeping an essentially constant voltage across R. You need to calculate the average current over that first, quarter cycle, to get the charge that passes, then add that from the constant voltage over the other 3/4 cycle.
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#6
(Original post by amell1234)
Ahh yes I've found the other thread on this question. Thank you so much that is so helpful. I have tried it but i'm still getting the wrong answer. Here is my working:
![Name: IMG_5165.jpeg
Views: 10
Size: 137.8 KB]()
Ahh yes I've found the other thread on this question. Thank you so much that is so helpful. I have tried it but i'm still getting the wrong answer. Here is my working:
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(Original post by RogerOxon)
Check your precision and rounding. I don't know what you're taught to use, but it looks slightly off to me.
Check your precision and rounding. I don't know what you're taught to use, but it looks slightly off to me.
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#8
(Original post by amell1234)
ahh yes you're right my calculations actually give 75.56 microC which to 2sf would be 76, but that still seems to be wrong?
ahh yes you're right my calculations actually give 75.56 microC which to 2sf would be 76, but that still seems to be wrong?
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#9
(Original post by amell1234)
Ahh yes I've found the other thread on this question. Thank you so much that is so helpful. I have tried it but i'm still getting the wrong answer. Here is my working:
![Name: IMG_5165.jpeg
Views: 10
Size: 137.8 KB]()
Ahh yes I've found the other thread on this question. Thank you so much that is so helpful. I have tried it but i'm still getting the wrong answer. Here is my working:
The graph may help you.
For the first T/4, the charges through the resistor is 13 μC.
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#10
(Original post by RogerOxon)
Sorry - I don't see an error. I got slightly different values using very high precision for pi, but I don't know what precision they expect.
Sorry - I don't see an error. I got slightly different values using very high precision for pi, but I don't know what precision they expect.
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