Circuit Analysis: Current flowing from negative to positive?

In summary, the conversation is discussing the assignment of KCL equations for a circuit, specifically the notation for current flowing away from Node C. The writer is questioning whether the sign of the current should be switched in cases where the polarity of the circuit is also switched. They request clarification or confirmation of this concept.
  • #1
t_jorgic
2
0

Homework Statement



http://images.4chan.org/sci/src/1340320682704.jpg

I am to write KCL equations for this circuit. Why is it that the current flowing AWAY from Node C is written as V2(t). I thought that when a current was flowing AWAY from a node, the current would be -V2(t)??

Homework Equations





The Attempt at a Solution



My guess is this.

Normally a current flows from + to -. If this is true then:
> Current is negative when flowing away from a node and positive when flowing toward a node.

Unless the polarity is switched (like it is in the circuit diagram in which case, the sign if the current is switched? But i don't know if this is true or not. can anyone confirm or deny this?
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
It would be helpful if you would show the circuit you are talking about.

Just listing an entire website is not helpful
 

1. How does current flow from negative to positive in a circuit?

Current flows from negative to positive in a circuit due to the movement of electrons. Electrons are negatively charged particles that are attracted to the positive terminal of a voltage source, causing them to flow in that direction.

2. Why is current measured in the opposite direction of electron flow?

Current is measured in the opposite direction of electron flow because historically, scientists believed that current flowed from positive to negative. This convention has been maintained and is still used today, even though we now know that electrons actually flow from negative to positive.

3. How is current affected by resistance in a circuit?

Current is inversely proportional to resistance in a circuit. This means that as resistance increases, current decreases. This relationship is described by Ohm's Law: I = V/R, where I is the current, V is the voltage, and R is the resistance.

4. Can current flow through an open circuit?

No, current cannot flow through an open circuit. An open circuit is a break in the path of the current, meaning there is no complete loop for the electrons to flow through. Without a complete path, the electrons cannot move and therefore no current can flow.

5. What happens to current when it reaches a junction in a circuit?

At a junction in a circuit, the current splits and flows through each branch of the junction. The total current flowing into the junction is equal to the total current flowing out of the junction, as dictated by the law of conservation of charge. This principle is known as Kirchhoff's Current Law.

Similar threads

Engineering Opamp adder circuit: Where does the "-" come from?
    • Engineering and Comp Sci Homework Help
Replies
8
Views
1K
Engineering Use voltage nodal analysis to solve for the current flowing in this AC circuit
    • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
Engineering Determining if voltage or current is positive or negative with sources
    • Engineering and Comp Sci Homework Help
Replies
10
Views
4K
Engineering Solve this Circuit using both Nodal Analysis and Mesh Analysis
    • Engineering and Comp Sci Homework Help
Replies
15
Views
3K
Solve Vo: Voltage Nodal Analysis w/ KCL Equation
    • Engineering and Comp Sci Homework Help
Replies
5
Views
2K
Engineering Solving Circuit Equations: A Struggle
    • Engineering and Comp Sci Homework Help
Replies
15
Views
1K
Complex RLC Circuit Problem (System of diff eqs)
    • Engineering and Comp Sci Homework Help
Replies
6
Views
730
Engineering Calculating the effective value and frequency of AC Circuit
    • Engineering and Comp Sci Homework Help
Replies
2
Views
999
AC - Node Voltage Method for difficult circuit
    • Engineering and Comp Sci Homework Help
Replies
4
Views
1K
Direction of current flow in KCL/Node Voltage Confusion
    • Engineering and Comp Sci Homework Help
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top