# Current & Potential Change After Passing a Resistor

• waqarrashid33
In summary, in circuit theory, current remains constant as it passes through a resistor, but the voltage or potential difference decreases as it travels around the circuit. To identify current, you only need to measure it at one point, but to determine voltage, you need to measure the potential difference between two points in the circuit.

#### waqarrashid33

I am confused on a question that arises in my mind:
that is "After passing the resistor the amount of current flowing through cross section of area is decrease or the energy of charges i.e Potential decreases".

I am guessing you are studying circuit theory and working you way around a circuit.

Firstly current.

What goes in at one end of a resistor comes out the other there is no change in current through the resistor.

Then the voltage, this does drop as you proceed in round the circuit. This is the potential difference across the ends of a resistor.

You can identify the current at a single point in a circuit.

You must state the voltage between two points in that circuit.

## 1. What is a resistor and why is it used in electrical circuits?

A resistor is an electronic component that is used to limit the flow of electric current in a circuit. It is typically made of a material that offers resistance to the flow of electrons, which helps to control the amount of current that passes through a circuit. Resistors are an essential part of electrical circuits as they help to regulate the flow of electricity and prevent damage to other components.

## 2. How does the passing of current through a resistor affect its properties?

When current passes through a resistor, it causes a voltage drop across the resistor, which in turn generates heat. As a result, the resistor's resistance may change, causing a change in the amount of current that can pass through it. This phenomenon is known as Ohm's Law, which states that the current through a conductor is directly proportional to the voltage across it, and inversely proportional to its resistance.

## 3. What factors determine the potential change after passing through a resistor?

The potential change, also known as voltage drop, across a resistor is determined by the amount of current passing through it and its resistance. The higher the current, the higher the voltage drop will be, and the higher the resistance, the lower the voltage drop will be. Temperature can also affect the potential change after passing through a resistor, as an increase in temperature can cause a change in resistance.

## 4. Can a resistor change the current passing through a circuit?

Yes, a resistor can control the amount of current passing through a circuit. As mentioned earlier, resistors offer resistance to the flow of electrons, which limits the amount of current that can pass through a circuit. By changing the resistance of a resistor, the amount of current can also be changed, thus controlling the flow of electricity in a circuit.

## 5. How does a resistor affect the potential difference in a circuit?

As current passes through a resistor, a voltage drop occurs, which affects the potential difference in a circuit. The presence of a resistor in a circuit can reduce the potential difference, as some of the energy is dissipated as heat in the resistor. This reduction in potential difference can affect the functioning of other components in the circuit, making resistors an important element in electrical circuits.