Electronic Devices - Semiconductors - Discussion
Discussion Forum : Semiconductors - General Questions (Q.No. 5)
5.
As the forward current through a silicon diode increases, the internal resistance
Discussion:
28 comments Page 1 of 3.
Kanika said:
1 decade ago
According to ohms law V=IR.
So current is inversely proportional to resistance.
Hence as the current increases, resistance decreases.
So current is inversely proportional to resistance.
Hence as the current increases, resistance decreases.
SARAN said:
1 decade ago
R=V/I
S Chakraborty said:
1 decade ago
R is the constant of proportionality . So . we can't say that R will decrease as current increases as per Ohm's Law . Of course R will decrease in this case. In case of diode, the dynamic resistance is related to the current by R=(Thernmal Voltage )/ Current through the diode , at room temp R=(26 mv)/I. Hence the result.
PRASANNA said:
1 decade ago
But diode is a non-linear device. It does not obey ohms law.
Prithvi said:
1 decade ago
@prasanna, I too think the same. Semiconductors do not obey ohm's law.
Nitin said:
1 decade ago
Internal resistance rd= 26 mV/Diode current.
So it decreases when forward current increases.
So it decreases when forward current increases.
Krishnakumar said:
1 decade ago
It doesn't obeys ohms law. Dynamic resistance is the only reason for this since it depends upon temperature and current.
Narvaneni.suresh said:
1 decade ago
According to ohms law V=IR. So the current is inversely proportional to resistance. The resistance decreases in forward bias.
Poonam patel said:
1 decade ago
A real diode has 2 components to the forward resistance. One is the apparent resistance of the PN junction and that decreases with increasing current. The other is a parasitic resistance and it is assumed to be constant.
Narendra singh lodhi said:
1 decade ago
Vt/I dynamic resistance .
so r increases
so r increases
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