# Does Voltage Drop Across A Resistor: Why, How And Detailed Insights

Does voltage drop across a resistor? As we all know, every conductor offers some resistance to the flow of electrons, so there is always a voltage drop between two points regardless of the presence of the resistor in the path of the flow of current.

There is a voltage drop (or electric potential drop) across the resistor as it provides resistance to the flow of electric current. The value or magnitude of voltage drop depends upon the magnitude of the resistance of the resistor.

The voltage drop can vary with the type of material used to create the part of the electricity, the diameter of the path of flow of electricity, the length of the path of the electricity, and the temperature of the material through which electricity is passing.

What is voltage drop across a resistor?

A voltage drop across a resistor is the amount of decrease in potential energy when the voltage is flowing through a resistor.

The essential property of a resistor is to tender or provide resistance to the flow of electric current or electric energy passing through it. Image Credit: User:Wtshymanski, Electrostatic definition of voltage, CC BY-SA 3.0

#### Why does voltage drop across a resistor?

For example, in a circuit, a resistance R provides the reduction in current or voltage, with different magnitude of the resistance R; for any desired value of the decrease in current or voltage, the resistance value for any resistor can be selected accordingly. The magnitude of a resistor can be determined by referring to the colourcoding of any resistor. When choosing the required resistor, maximum allowable current or maximum voltage rated for a resistor should be considered. The manufacturer specifies the power rating of a resistor, which provides us with the maximum power in what the resistor can handle without being destroyed. Registers are sometimes used to control the flow of current in a circuit.

Does voltage drop across a single resistor?

There is always some voltage drop across any wire or circuit regardless of the presence of the resistor, as wire also has some resistance.

It doesn’t matter where there is one resistor on more than one resistor in the circuit; the voltage drop across any component depends upon the magnitude of the overall resistance offered by that component. Image Credit: GorillaWarfare, Ohm’s Law with Voltage source TeX, CC0 1.0

According to Ohm’s law at a constant temperature , the current is directly proportional to the voltage flowing through a resistor when the magnitude of the resistor is kept constant. So when the value of the resistor changes, then the respective value of voltage and current also changes.

The voltage drop (or electric potential drop)across any resistor is zero only when the magnitude of resistance is zero. The voltage drop across any resistor is the maximum when the magnitude of the resistance is enormous, where infinite resistance means that open circuit where the current does not flow at all.

How much does voltage drop across a resistor?

The voltage drop across any circuit component can be calculated by using different circuit laws.

The voltage drop across any resistor can be determined with the known (magnitude of) voltage and known (magnitude of) current. As we know from Ohm’s law.

Resistance = Voltage/ Current

If we consider the magnitude of voltage is constant, then the magnitude of resistance decreases with the increase in current. And when the magnitude of the current is kept constant, the value of resistance increases with the increase in voltage.

Why there is voltage drop across resistor?

To understand electrical resistance we need to understand the current and voltage.

The resistance or obstruction of the wire may increase or decrease with the temperature, its depend upon the material, characteristics of the material such as conductivity and resistivity, the length of the material, etc.

The wire with a large cross-section area offers less resistance to the electricity flow, where is the resistance increases with the increase in the length of the wire through which the electricity flow. A conductor offers minimum resistance for the electric flow. Still, in reality, no material provides zero resistance to the flow of electrons, which means there is no ideal conductor which provides zero resistance to the flow of electricity.

From the basic as we know, electrons have negative charge which attracts positive charges and repels the negative charge, that’s why when when the electrical charge difference created between two points due to any phenomenon like external force or any internal chemical reaction, which makes the voltage difference for potential difference between two points the greater the difference the the more energy stored at each points, so when you connect a wire between the terminals of this charge difference the electrons at the negative end start flowing towards the positive end of the circuit, but the flowing of electrons from one side to another side is not easy the wire always offers some resistance are hindrance to the flow of the electron.

Sneha Panda

I have graduated in Applied Electronics and Instrumentation Engineering. I'm a curious-minded person. I have an interest and expertise in subjects like Transducer, Industrial Instrumentation, Electronics, etc. I love to learn about scientific researches and inventions, and I believe that my knowledge in this field will contribute to my future endeavors. LinkedIn ID- https://www.linkedin.com/in/sneha-panda-aa2403209/