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diodes

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colors

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hi,
i am a little confused with diodes. if i take a 10v source and just put a diode to it.
now the voltage drop across the diode will be 10v , but forward voltage drop of a diode 0.6v.
a little confused..
 
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have i put my question properly? actually , i should have put a resistor also but what i want to know is that in case 10v appears across a forward biased diode , which may a part of a complex ckt, what is the drop across diode?0.6 or 10v.
 
One wood assume one of two things:
1) You connected it backwards and it is in the blocking mode.
or
2) You allowed too much current to flow through it and you burned it open.

Two is not very likely since diodes tend to fail shorted rather than open. I, of course, refer to small signal diodes. I have seen power diodes that have reduced themselves to two pieces of wire and charcoal deposited on the sides of the cabinet as the result of shorting out.

You do have the end with the stripe pointing to the negative voltage source, correct?
 
0.4 if it is germanium, 0.7 if it is silicon and at normal current levels. I assume that you are not talking a megawatt power plant.
 
Are you sure you are using a normal Diode and not a 10V Zener??
 
somebody please check the rules i have made-
drop across forward biased diode-0.7 if it conducts
drop across reverse biased- it's an open circuit
drop across zener when forward biased- 0.7 if it conducts
drop across reverse biased zener- 5.3 (does it conduct)?(not leakage)
the voltage across zener is fixed whatever current flows through it in reverse bias and the current can increase to any value.
 
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somebody please check the rules i have made-
drop across reverse biased zener- 5.3 (does it conduct)?(not leakage)
the voltage across zener is fixed whatever current flows through it in reverse bias and the current can increase to any value.
Well, any current up to the power dissipation rating of the diode. Most are rated something like a half watt or one watt. The current times the voltage drop has to remain below that rating.

Yes, it conducts. The series resister in the input path keeps the current under control. If you connect a 5 volt zener across a 10 volt supply, you get burnt zener. If you connect a resister and a zener across a supply, you get the voltage of the zener at the junction of the zener and the resister. That is the point you tap the output voltage.
 
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You cannot consider just a diode and a 10V source. You also MUST also know what element is in series with the diode back to the other end of the source!!!!
 
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