# determine the forward voltage and current across Rc?

### 1 Answer

- FredLv 72 months ago
I hope I have this right. In question (a) with a 10 volt power supply, a 1000 ohm resistor and a silicon diode, firstly the silicon diode had a voltage drop of .6 of a volt across it, so there is 9.4volts across the resistor. Ohms law says that amps equals the voltage divide by the resistance so that is 9.4volts divided by a thousand ohms which equals 0.0094 amps or 9.4 milliamps. Your forward voltage is 9.4 volts and the current is 9.4 milliamps.

For question (b) the germanium diode the voltage drop is .2 of a volt across the diode, so with a 10 volt power supply the forward voltage would be 9.8volts. Put through a 1,000 ohm resister Ohms law says Amps is 9.8 volts divided by a 1,000 ohms so the forward voltage is 9.8 volts and the current is 0.0098 amps or 9.8 milliamps.

I have just noticed that in the diagrams the diodes are reversed. If I am right in diagram (a) the diode is the wrong way around to allow any current flow, so make sure your diagram is correct and you did not mistakenly draw the diode backwards. If your diagrams are drawn correctly in diagram (a) there would be no current flow.