diode and ressitor are connected to 2volt ,I=20mA,then it is reversed I=50mA,what is forward resistance of diode and resistor ,give me hint
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7 Answers
1sir ur method seems to be wrong,neither the forward nor the backward resistance is zero and it is not mentioned either it is parallel or series
62i think i was wrong
i shot off too fast on this one...
actually i think now that they will be in parallel :D
sorry for confusing all of ur...
62v=iR will give the rresistance of the resitor when it is backward biased (assuming very high resistance of the diode!)
so R=2/50mA = 2000/50 = 40 ohms...
when forward biased,
effective resistance is 50R/(50+R)
2=20. 50R/(50+R)
1/500=R/(50+R)
50+R=500R
R=1/10 ohms..
now i hope this is correct :)
1man , I think the reverse bias current should be 50μA not 50mA . please check.
62that is what .. you have to first justify that it is in parallel..
cos in series.. the diode becomes very large resistor.. so the current would have fallen by a huge quantity..