# Electric potential difference at the ends of a resistor

• greg_rack
In summary, the current flowing through the equivalent resistor in a circuit with two parallel resistors is equal to the sum of the individual currents. Additionally, in a parallel circuit, the potential difference between any two points connected by straight pieces (equipotentials) is the same, regardless of the specific points. This means that in the given circuit, VAB = VAC = VAD.
greg_rack
Gold Member
So, having two parallel resistor ##R_{1}## and ##R_{2}## , the current flowing through the equivalent one will be ##I_{eq}=I_{1}+I_{2}##.
Now, it comes the point I'm not totally getting: why is ##V_{eq}=V_{1}=V_{2}##? These V's are the difference of potential measured between which points?

referring to this ugly image representing the two parallel resistors:
is ##V_{1}=V_{B}-V_{A}## or ##V_{1}=V_{D}-V_{A}##? Or, is ##V_{B}-V_{D}## since they're in the same conductor?
As you can see, I think I haven't clear how does potential varies after that current passes through a resistor.

Look at the circuit. By convention the straight pieces connecting the resistors (wiggly lines) are equipotentials. This means that the potential difference between any two points, which have no circuit element between them, are at the same potential.

vanhees71
kuruman said:
Look at the circuit. By convention the straight pieces connecting the resistors (wiggly lines) are equipotentials. This means that the potential difference between any two points, which have no circuit element between them, are at the same potential.
So, in this case, ##B## and ##C##(?)

greg_rack said:
So, in this case, ##B## and ##C##(?)
Yes, and also D. You have VAB = VAC = VAD.

etotheipi and greg_rack
kuruman said:
Yes, and also D. You have VAB = VAC = VAD.
Got it, thanks!

## 1. What is electric potential difference?

Electric potential difference is the difference in electric potential between two points in an electric circuit. It is measured in volts (V) and represents the amount of work needed to move a unit of electric charge from one point to another.

## 2. What is a resistor?

A resistor is an electrical component that is used to control the flow of electric current in a circuit. It is designed to have a specific amount of resistance, which is measured in ohms (Ω).

## 3. How does a resistor affect electric potential difference?

A resistor creates a drop in electric potential difference by converting electrical energy into heat. This drop in potential difference is proportional to the amount of resistance in the circuit and is described by Ohm's law: V = IR, where V is the potential difference, I is the current, and R is the resistance.

## 4. What factors affect the electric potential difference at the ends of a resistor?

The electric potential difference at the ends of a resistor is affected by the amount of resistance, the current flowing through the resistor, and the voltage applied to the circuit. It is also affected by the material and temperature of the resistor.

## 5. How can the electric potential difference at the ends of a resistor be measured?

The electric potential difference at the ends of a resistor can be measured using a voltmeter, which is a device that measures the potential difference between two points in a circuit. It can also be calculated using Ohm's law if the resistance and current are known.

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