Voltage dependent Current source

AI Thread Summary
The discussion revolves around calculating Vout at t=0.782s for a voltage-dependent current source problem. The initial calculations led to a result of 8.990V, but the correct answer is -8.99V, as the system requires reversing the sign twice. Participants clarified that the connecting wire does not affect the outcome, and both Vout at t=0s and t=0.782s were submitted correctly. The confusion stemmed from the interpretation of resistor values and current direction in the circuit. Ultimately, the correct Vout at t=0.782s was confirmed to be -8.99V.
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Homework Statement


12.jpg


Find Vout at t=0.782s (I already found Vout at t=0 s. It is 0 V.)

Homework Equations


V=IR

The Attempt at a Solution


First I found Vs = 9*sin(14*0.782)=-8.989817V (with t in radians)
Since Rpi is in parallel with the Vs, its voltage Vpi also equals to -8.98917 V.
Since the dependent source is I=10^-3*Vpi= -8.989817E-3 A, it is the same current traveling through the 1000 ohms resistor in the right loop.
Using the equation: Vout=IR=8.989817E-3A*1000ohms=8.990V (Current is positive in this case since the current direction is opposite of the passive configuration. That is, it is going from - to + instead of + to -.)

Apparently, my answer is wrong. Would anyone please help me to see where I am doing wrong here? (I wonder how does the wire connect the two loops affect the situation. Is it possible that the R in Vout=IR is not 1000, but 1050 (50 ohms resistor in the left loop since both resistors might be in series?)

Many thanks in advance!
 
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I tend to agree with you. The question did ask for V at t = 0 and at .782 msec. Did you submit both answers? The connecting wire will make no difference.
 
Yes

barryj said:
I tend to agree with you. The question did ask for V at t = 0 and at .782 msec. Did you submit both answers? The connecting wire will make no difference.

Thanks barryj.

Yes, I submitted 0 for t=0 s and it is correct.

The only problem I have is Vout when t=0.782s.
 
Problem solved! Thanks everyone.
 
What was the answer?
 
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The answer is...

barryj said:
What was the answer?

It is --8.99 since the system wants to see students reverse the sign twice.
 
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