# Search results

1. ### Proof of Euler's Theorem

Yes, I am aware that -1 and P-1 are the same in modP. Thanks for trying to help, but I figured it out on my own!
2. ### Proof of Euler's Theorem

I am trying to show that -1 or P-1 is a quadratic residue modP sorry I am using exact language from Euler's work- which is a bit outdated.
3. ### Proof of Euler's Theorem

Homework Statement If the divisor P is a prime of the form 4q+1 then the number -1 or P-1 is certainly a residue. Homework Equations The Attempt at a Solution First the book told me to prove that 1 and -1 are the only two remainders that are their own reciprocals modP...
4. ### Output impedance of a Pass Transistor

wait wouldnt it just be a voltage divider and thus that would mean: VL=Vout(Rout/Rout+RL) Then simplifying, would get: Rout=VLRL/(vout-vl)? But if that is the case, do we just disregard the 1k resistor?
5. ### Output impedance of a Pass Transistor

well I believe we would do the change in voltage over the change in current and that would give us the internal resistance... however, finding the current in this situation is a little more difficult :/
6. ### Output impedance of a Pass Transistor

This is for a lab so it says to find the output impedance by finding the change in voltage when the circuit is loaded by 150 ohms.
7. ### Output impedance of a Pass Transistor

so then how could we measure the output impedance with the load resistor? We could measure the voltage drop across the resistor, but I don't know how that could help us with the output impedance
8. ### Output impedance of a Pass Transistor

so then my approximate output impedance would just be that divided by 200, which would give me 20.24 ohms? Also, is that 1k resistor a load resistor? Because for the next part it says suppose we added in a load resistor. In order to do that, would I just put it in parallel with the 1k resistor?
9. ### Output impedance of a Pass Transistor

I don't think that we have any equivalent circuit models... The hint my teacher gave is that it is approximately equal to the output impedance of the circuit that supplies the base current divided by β. But what is the output impedance of the circuit that supplies the base? is it that 4047.6...
10. ### Output impedance of a Pass Transistor

i've never seen the pass transistor before.... but i've seen an emitter follower. I wasn't positive, but I thought that the input impedance would be the 10k and 6.8k resistors in parallel, which would give me about 4047.6. However, I'm not sure about the output impedance. Usually it is just...
11. ### Output impedance of a Pass Transistor

Homework Statement Calculate the output impedance of the emitter-follower circuit called a pass transistor. Assume that beta=200 **See attached diagram** Homework Equations The Attempt at a Solution Not really sure how this works, I thought it would just be 1k cause that is the...
12. ### Npn transistor with a diode

Good catch :D Thanks so much for the help!!! I really appreciate it!
13. ### Npn transistor with a diode

Thanks so much, that makes sense!! However, am I right about the PNP being the other direction because then the current would be flowing in the opposite direction, so then the reverse current would be limited by a diode that is biased from B to E?
14. ### Npn transistor with a diode

Well theoretically it should drop all of it :D, so the max should be zero with the diode I realized that after I typed it.... So for the PNP would I just reverse the bias of the diode?
15. ### Npn transistor with a diode

Well without the diode, wouldn't there have to be a bigger voltage drop in the base-emitter junction? With the diode, wouldn't it drop some of that voltage so the junction doesn't have to drop it all?
16. ### Npn transistor with a diode

Well it looks like since it is reverse bias when current is flowing from B, so it has to go through the transistor. When current flows from E back to B it is going through the diode which is forward biased, which will create a .6V drop in the voltage... which i think they said is already pretty...
17. ### Npn transistor with a diode

Homework Statement The absolute max voltage rating for the base-emitter voltage is the lowest of all values. This low value means the B-E junction must be protected from a high reverse voltage. A diode is used for an npn transistor. Explain its function and conditions under which...
18. ### Charging a battery circuit

thanks for confirming :D
19. ### Charging a battery circuit

Homework Statement Make a modification so that the battery is charged by the DC supply at a current of 10mA **See attached diagram** Homework Equations The Attempt at a Solution Well I know that I would put in a resistor in parallel with the diode. However, I don't know how...
20. ### Circuits with Diodes

thanks so much for the help :D
21. ### Circuits with Diodes

so would the fact that I have two "normal" diodes in the same biased in the same direction in parallel change what my output waveform would look like, or would it just resemble what it would look like if I had one diode in the circuit?
22. ### Circuits with Diodes

since my zener diode has a threshold of 6.3V, and since my voltage is 5V peak to peak, it will never reach that threshold, so won't it always just be zero output?
23. ### Circuits with Diodes

I am only still stuck on the first one!
24. ### Circuits with Diodes

Homework Statement sketch the output waveforms when a 5Vp sine wave with a frequency of 100 Hz is applied to each of the following circuits **see attached diagrams** Homework Equations The Attempt at a Solution
25. ### Circuit with a zener diode

So, now if the load resistor is taken out, we would have a diode that would still have no current running through it (because the direction of the arrow in the zener). So wouldn't the power being dissipated by the resistor be the same?
26. ### Circuit with a zener diode

So, what if the resistor was 100 ohms? Then the power rating would be 144/100, which would be 1.44 watts. If we have a a 1/4 watt resistor, and a power greater than that being dissipated by it, what would happen to the resistor?
27. ### Circuit with a zener diode

Well it would have to be all of the voltage drop through the resistor, so I'm guessing that it would also dissipate all the power. So would that be 1/4 watt or would we do V^2/R so it would be 144/1000 W?
28. ### Circuit with a zener diode

well if the zener is shorted then it would have no current running through it, so then the voltage across it would be zero
29. ### Circuit with a zener diode

oh wait, well i have the power as 1/4 W and the voltage as 5.1V, so wouldn't the current be .25/5.1V. But, that doesn't make sense though cause the V is given, so isn't that the voltage drop across the zener?
30. ### Circuit with a zener diode

I have no idea.... I would need to know the current through the zener, and I don't know how to figure that out :(