Circuits: Direction of Current

In summary, the conversation discusses finding the direction of current through a resistor in a circuit with multiple batteries. The diagram shows a square circuit with batteries of different voltages and a resistor. The solution is to add the voltages of the batteries in series, subtracting if the current goes from positive to negative. It is concluded that the current through the resistor is from right to left.
  • #1
Sky.Anthony
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0

Homework Statement



The question gives me a diagram and is asking me to find the direction of the current through a resistor. I understand that current always flows from positive to negative terminal of the power source but the thing is, I'm given 3 batteries and a resistor (which I don't know how to figure out). The diagram goes like this (I'll have to describe in words):

Picture a square circuit; I will describe clockwise starting from bottom of the square. On the bottom of the circuit, there is a battery of 4V with the positive end on the left side of the page and negative on the right side. On the left side of the square, there is another battery of 2V with negative on the bottom and positive on the top. There is a resistor on the top of the square. On the right side of the square, there is a battery of 9V with positive end on top and negative end on bottom.

Homework Equations



None.

The Attempt at a Solution



Apparently, the current through the resistor is from right to left. I don't understand how I would figure it out because we have positive to positive ends of the resistor!
 
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  • #2
When you have voltage sources (like batteries) in series you figure out the voltage by starting at one end and going though all the batteries and adding it all up. If you go from a negative terminal to a positive terminal through a battery you add the voltage. If you go through a battery from positive to negative then you subtract the battery's voltage.

If you connect the + terminals of a 10 volt and 11 volt battery together then between the free - terminals you will measure 1 volt.
 

1. What is the direction of current flow in a circuit?

The direction of current flow in a circuit is from positive to negative. This is known as conventional current flow, as it was originally believed that current flowed from positive to negative. However, in reality, electrons flow from negative to positive.

2. How is the direction of current flow determined?

The direction of current flow is determined by the polarity of the voltage source in the circuit. The positive terminal of the voltage source is considered the starting point for current flow, and the negative terminal is considered the end point.

3. Can the direction of current flow change in a circuit?

Yes, the direction of current flow can change in a circuit. This can happen if the polarity of the voltage source is reversed or if there are components, such as diodes, that only allow current to flow in one direction.

4. What is the difference between AC and DC current in terms of direction?

AC (alternating current) changes direction periodically, typically 60 times per second in the United States. The direction of DC (direct current) remains constant. In terms of direction, AC current flows both ways, while DC current only flows in one direction.

5. How does the direction of current affect the functionality of a circuit?

The direction of current does not affect the functionality of a circuit, as long as it is flowing through the circuit in the intended direction. However, reversing the direction of current in certain components, such as motors or LEDs, can cause them to function differently or not at all.

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