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anand raj
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Homework Statement
the voltage Vc in the figure is always equal to
2 Relevant equations
The Attempt at a Solution
From kirchhoffs law,
-Vc+4+5=0
Vc=9 V
will Vc always equal to 9 V or it will vary?
the voltage Vc in the figure is always equal to
CWatters said:Is that really the problem statement word for word? I suspect not because it can't easily be answered.
At best you can say...
VC = 5V + 4V + whatever the voltage is across the 2A current source.
The latter term is unknown.
The current source will adjust it's voltage so that KVL holds. That depends on Vc. If the current source is an ideal current source then Vc could be anything. It could be negative or huge (eg-1,000,000V). The current source will do whatever it takes to make KVL hold. That allows Vc to be anything.
CWatters said:Now that you mention it perhaps it is an ammeter. It would make some sense given the odd wording of the question.
NascentOxygen said:Though even if it is established that it's an ammeter, we are still left with an unanswerable question.
What's in the box? Perhaps anand raj could tell us if there is some overlooked detail that should be shared. I'm thinking the box represents a variable load. But only because if it were to represent a fixed load, the question would seem trite.
Nominating an ammeter reading of 2A seems pointless and confusing if the load is intended to be variable, though.
If it's an ammeter icon, it may not tell us the direction of the current. Besides, I see nothing here that suggests the box contains a voltage/current source of any description.rude man said:If it's an ammeter it doesn't matter what's in the box, long as it results in a current of 2A:
NascentOxygen said:If it's an ammeter icon, it may not tell us the direction of the current.
So? No one modifies circuit icons for each instance.rude man said:I could haved sworn I saw an arrow pointing from left to right.
The Electrician said:Vc can't be just anything. Vc depends on what's inside the box.
If the circuitry in the box is represented by its Thevenin equivalent: a voltage source Vth in series with a resistance Rth, then Vc = Vth - 2*Rth.
A combination of a current source in series with a resistor and a voltage source behaves just like the current source alone. Vc won't depend on the 2Ω resistor and the 5V source; it depends only on what's in the box; not only is the 5V source irrelevant, so is the 2Ω resistor.
If nothing is in the box, just a pair of terminals hanging in the air, then Vc→∞, and Vc will be whatever it takes to sustain the arc across the terminals.
For some really kinky circuit elements, see:
http://en.wikipedia.org/wiki/Norator
http://en.wikipedia.org/wiki/Nullator
http://en.wikipedia.org/wiki/Nullor
CWatters said:I don't think much more can be said until the OP replies.
anand raj said:
A current source is an electronic component that provides a constant flow of electric current in a circuit. It is represented by a symbol of a circle with an arrow pointing outwards.
A voltage source is an electronic component that provides a constant voltage difference between its two terminals in a circuit. It is represented by a symbol of a straight line with a positive and negative sign.
A resistor in series is a type of circuit configuration where multiple resistors are connected one after the other. The same amount of current flows through each resistor, and the total resistance is equal to the sum of individual resistances.
In a series circuit, adding a resistor will decrease the total current flowing through the circuit. This is because the total resistance increases, and according to Ohm's Law, the current is inversely proportional to the resistance.
To calculate the total resistance in a series circuit, add the individual resistances of each component. For example, if there are three resistors with values of 10 ohms, 20 ohms, and 30 ohms, the total resistance would be 10 + 20 + 30 = 60 ohms.