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# AQA AS Physics Help - Paper One (24th May)

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1. Can someone explain this question to me, please? You're expected to use p=(v^2)/R . Since power is inversely proportional to resistance, as resistance increases, the mark scheme says, power decreases. The thing I don't understand is that if resistance is increasing, surely voltage is changing too - so how can we assume it's gonna stay constant?
What about P=(I^2)R ? Why can't we assume current remains constant and say, as resistance increases, that power is also going to increase?

I'm missing something here.

Can someone explain this to me?
Thanks.
2. (Original post by uuujac61)

Can someone explain this question to me, please? You're expected to use p=(v^2)/R . Since power is inversely proportional to resistance, as resistance increases, the mark scheme says, power decreases. The thing I don't understand is that if resistance is increasing, surely voltage is changing too - so how can we assume it's gonna stay constant?
What about P=(I^2)R ? Why can't we assume current remains constant and say, as resistance increases, that power is also going to increase?

I'm missing something here.

Can someone explain this to me?
Thanks.
I hope this explains it for you!! If you've got any more questions ask away and I'll do my best to help!! Good luck for tomorrow!!
3. (Original post by Starkidemmax)
I hope this explains it for you!! If you've got any more questions ask away and I'll do my best to help!! Good luck for tomorrow!!
Thank you!

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