# Electricity A level physics

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#1
https://youtu.be/MTx3PG5e1xk?list=PL...WkM0AQS&t=1224

The last question here, did he get part 2 wrong?

Isnt the resistor R meant to have changed its resistance, because it now has 3.6v rathher than 2v like it did in Q1.

If so, how would I work out this new resistance in R for Q2
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#2
why did he say 'this is staying at 1.5k ohms'?

Isn't a resistor in a potential divider meant to get a different resistance, if the voltage changes?
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4 weeks ago
#3
No he didn't make a mistake
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4 weeks ago
#4
Why would the resistor change its resistance? Resistance of the normal should be constant as far as I am aware.
Last edited by blackugo; 4 weeks ago
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#5
(Original post by blackugo)
Why would the resistor change its resistance? Resistance of the normal should be constant as far as I am aware.
i get it now, i thought as voltage across resistor in potential divider drops, the resistance drops. But this is only true for variable resistors or thermistors etc
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4 weeks ago
#6
(Original post by gorilla_08)
i get it now, i thought as voltage across resistor in potential divider drops, the resistance drops. But this is only true for variable resistors or thermistors etc
The resistance doesn't drop because of the voltage. The voltage drops because of the resistance because the p. d is shared in the ratio of the resistances.
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