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How would you find internal resistance in part b)ii

ihaventshowered

Please help Screenshot 2020-10-31 at 13.30.30.png

(edited 3 years ago)

Screenshot 2020-10-31 at 13.31.04.png17.8KB

Reply 1

lordaxil

Using Ohm's law: you need to know the current flowing through power supply (hint: how is this related to value in b(i)?) and voltage drop across power supply (hint: question tells you that most of the p.d. is across the 470 Ohm resistor).

oh my god thank you

oh my god thank you
i get that current is 0.031A but what about the voltage PLEASE

Reply 4

lordaxil

Yes - current is correct, well done.

If there is 15 V across the power supply with no current flowing, and the voltmeter reads 14.5 V across the 470 Ohm resistor with current flowing, what is the potential drop across the power supply?