Voltage vs Voltage Drop: Comparative Analysis

This article illustrates the key differences between voltage vs voltage drop. We often refer to voltage and voltage drop as the same entities. But the fact is that they are different and possess unique attributes.

Here are the basic differences between voltage vs voltage drop-

ParametersVoltageVoltage drop
DefinitionVoltage is the electrical pressure that drives charged electrons to flow from one place to another through a conducting material. We can also say, voltage is the difference of electric potential between two points in a circuit.Voltage drop is also a quantity associated with voltage, but it is not exactly the same as voltage. Voltage drop is the potential difference caused in presence of any obstacle in the circuit such as resistor, inductor or capacitor. It is the lost voltage.
Meaning in DCIn one directional DC current flow, as per ohm’s law, voltage is the simple product of current and resistance. DC voltage is constant.DC voltage drop is the potential difference from one point to another point when DC current passes through any resistive component between the points. 
Meaning in ACAC current flows bi directionally or changes its polarity over a certain period of time. Due to this change, voltage also varied periodically. It is the product of current and impedance.The concept of AC voltage drop is similar to DC voltage drop. Just like AC voltage, AC voltage drop considers impedance in a circuit instead of only resistance.
CalculationVoltage is calculated using ohm’s law, by multiplying current and resistance. In capacitive and inductive circuits, capacitance and inductance are also taken into account along with resistance.Voltage drop calculation is just the same as voltage calculation as it is a part of voltage itself. Just in a circuit, voltage drop refers to only the drops occurred through reactances, but not the supply or source voltage.
MeasurementVoltage is measured with analog or digital voltmeter or multimeter. As voltage drop is a fraction of net voltage, it is measured with the same instrument used to measure the voltage.
Multimeter for measuring voltage vs voltage drop
Multimeter for measuring voltage and voltage drop; Image Credits: Wikipedia

When voltage and voltage drop can be the same?

Voltage and voltage drop is slightly different from each other. When we talk about the voltage vs voltage drop across any component such as resistor, capacitor or inductor in a circuit, it is the same as the voltage across it. 

Suppose, there are two resistors in a series configuration. A source voltage is fed to the circuit. The voltage is the supply voltage as well as the voltages through the individual resistors. But individual voltages will be the only voltage drops in the circuit. This applies for DC as well as AC circuits like RC, LR or RLC circuits.

Voltage vs voltage drop- FAQs

Electric potential vs voltage

Electric potential is known as the energy per unit charge attained or lost when any charge flows from a particular point with zero electric  potential. Voltage is the potential difference between any two points.

Let us take an example. Suppose, the potential of an arbitrary point P relative to a fixed point B is 100 volts, and the potential of the point Q is said to be 120 volts. Then the voltage or potential difference between the points P and Q is (120-100) = 20 volt. Here 100 volt and 120 volt are the electric potentials but 20 volt is the voltage. 

Voltage vs voltage drop in a circuit

What are the reasons of voltage vs voltage drop in a circuit?

Voltage is a very basic property of charge. It is the driving force that moves the electrons from one point to another and changes magnitude. Voltage is generated through electro chemical reaction or magnetic induction.

Voltage drop is typically caused by the effect of resistors, capacitors and inductors in the circuit. When current flows through a closed circuit where these reactive elements are there, supply voltage decreases when current meets any element. The more the reactance, the more the voltage vs voltage drop.

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