A) two p-n germanium diodes are connected in series opposing. A 5v battery is impresseed?

Question

A) two p-n germanium diodes are connected in series opposing. A 5v battery is impresseed

upon this series arrengement. find the voltage across each junction at room temperature.

Assume that the magnitude of zener voltage is greater than 5V.

note that the result is independent of the reverse saturation current.is it also indepedent

of tempereture?

HINT-assume that the reverse saturation current floes in the circuit and then justify this

assumption.

B) if the magnitude of the zenar voltage is 4.9v,what will be the current in the circuit?

the reverse saturation current is 0.005mA.

C) inthe same circuit the zener breakdown voltage is 2.0v. the reverse saturation current

is 0.005mA.if the silicon diode resistance could be neglected,what would be the current?

D) If the ohmic resistence is 100 ohmes what is the current?

please answer me hurry!this is in emergency ! please... please......

Answer 1

a) You get the leakage current flowing, 0.005mA., that's all.

Voltage: one has 0.3 volts on it, the other has 4.7 volts across it.

b) doesn't change, voltages are less than the zener voltage (I think you mean the breakdown voltage).

c) Current is limited only by the battery resistance and the resistance of the diodes, one in breakdown, one in conduction. The current would probably increase until one of the diodes burned out. How did the diodes change from Ge to Si?

d) If you put a 100 ohm resistor in series, or the diode's internal resistance totaled 100 ohms, the current is (5 - 2.0 - 0.3) / 100 or 27mA.