Calculate I1, V Drop R1, V Drop R2, I2 for Circuit w/Diode

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The discussion focuses on calculating current I1, voltage drops across resistors R1 and R2, and current I2 in a circuit with a non-ideal diode. Given a 5V input and resistances of R1 and R2 at 1k ohm each, the voltage across R2 is 5V, leading to I2 being 5mA. The diode's forward voltage drop of 0.7V results in a voltage drop across R1 of 1.43V, yielding I1 as 1.43mA. Participants clarify that since the circuit operates under DC conditions, I2 and I1 would not have the same waveform if the circuit were AC. The conversation highlights the importance of distinguishing between AC and DC signals in circuit analysis.
pyroknife
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I attached the circuit.
I need to find I_1, Voltage drop across R1, voltage drop across R2, and I_2. We're assuming the diode is 'not' ideal.

Vin=5V. R1=R2=1kohm
R3=2kohm


voltage across R2=Vin=5V
I2=5/1kohm=5mA

The real diode drops about 0.7 V. So using voltage divider gives voltage across R1=(R1/(R1+R3))*(5-0.7)=1.43V

Then I1=1.43/1k=1.43mA


Is this the right idea?
 

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without comment on the correctness of your specific numbers, let me ask you this:

Do you feel that I2 = 5m in the same sense that I1 = 1.43ma. That is, other than magnitude, would they have the same waveform if graphed?
 
phinds said:
without comment on the correctness of your specific numbers, let me ask you this:

Do you feel that I2 = 5m in the same sense that I1 = 1.43ma. That is, other than magnitude, would they have the same waveform if graphed?
I guess I don't see what you're asking.
This is a DC signal.

For an AC signal, the would not have the same wave form due to the diode.
 
pyroknife said:
I guess I don't see what you're asking.
This is a DC signal.

For an AC signal, the would not have the same wave form due to the diode.

Hm ... why do you suppose a DC source is labeled "Vin, VAC ?"
 
phinds said:
Hm ... why do you suppose a DC source is labeled "Vin, VAC ?"

Ignore the AC part, that's for another problem.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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