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Old Nov 1st 2017, 01:21 PM   #1
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Join Date: Nov 2017
Posts: 1
Basic Physics circuits

I know this is probably really simple , but i just don't understand how to work out a question like the one attached.
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Old Nov 1st 2017, 07:30 PM   #2
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7 ... So ...0.8A leaves the battery ...0.2 A goes through the branch with the diode , so the current going through the 18 Ohm must be 0.6 A ...use V=IR to find the voltage across the 18 Ohm ....

8. ..The answer to part 1 is also the voltage across the other branch with 46 Ohm in series with the diode ...you have the current , 0.2 , and the voltage ... this will give you the total resistance in this branch (use V=IR)

9 ... now you have the resistance of the diode , and the current going through it ..

Calculate the power using P=I xI x R ....(I squared R)
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Old Nov 2nd 2017, 02:30 AM   #3
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alistair, have you studied Kirchoff's two circuit laws or just series and parallel circuits?

I assume you have Ohm's law under your belt?
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