ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: VCEstudentguy on October 06, 2012, 11:03:17 am
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The question is attached. I'm a bit confused...wouldn't the answer be C because we have to point our thumb in the opposite direction that the current is flowing in and then by curling your fingers it would be into the page at point P, however, the answer says D? Where am I going wrong?
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Thumb in the direction of the current, not opposite.
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Question: Do we always describe magnetic fields as into the page/out of the page instead of to the left/right?
Doing the above question, I could've picked either A or D.
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Question: Do we always describe magnetic fields as into the page/out of the page instead of to the left/right?
Doing the above question, I could've picked either A or D.
Could you rephrase your question? I don't quite understand it :P
But yeah, into/out of the page literally means that, you just have to remember that it's in 3D, so your paper is the "base" it has two dimensions (left/right and up/down) then you will have into and out of the page, which is the other direction orthogonal to those two.
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OK, thanks but don't the rules apply for the flow of positive charges which would mean (?) that you put your thumb in the opposite direction? Because for some questions I have done so in the past and gotten the right answer, sorry for the late reply
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No, current is always taken as conventional current, which is the direction of your thumb.
Electron flow, of course, is in the opposite direction of the conventional current flow, but that's completely irrelevant to this question.
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OK so if it says current is flowing in this direction I put my thumb in that direction but if it says for example 'A lightning conductor gets a 'bolt from the blue'. This sends electrons in the conductor rushing downwards.' then I would point my thumb up?
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That's right, you've got it