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Voltage vs. Current: Key Differences Explained

voltage current ohm law resistance circuit

This article explains the fundamental differences between voltage and current, two crucial concepts in electronics. We’ll explore their definitions, how they’re measured, their effects, and their relationship to resistance.

Voltage

Voltage is the potential difference between two points in a circuit. Think of it as the “electrical pressure” that drives the flow of electrons. It’s what causes current to flow from a point of higher potential to a point of lower potential. This potential difference is often created by an electromotive force, such as that provided by a battery.

Current

Current, on the other hand, is the flow of electrons. More precisely, it’s the rate at which electric charge flows through a circuit. This flow is driven by the voltage (electromotive force).

Voltage vs. Current: A Detailed Comparison

Here’s a table summarizing the key differences between voltage and current, especially as they relate to resistance:

FeatureVoltageCurrent
DefinitionPotential difference between two points that causes current to flow.Flow of electrons. Result of electromotive force.
MeasurementMeasured by a Voltmeter.Measured by an Ammeter.
Unit1 Volt = 1 Joule/CoulombMeasured in Ampere (A), milliampere (mA), microampere (µA); 1 Ampere = 1 Coulomb/Sec.
Field CreatedCreates an electrostatic field.Creates a magnetic field.
Parallel CircuitsVoltage across components connected in parallel are of equal magnitude.N/A
Series CircuitsN/ACurrent flowing through components connected in series is of equal magnitude.
Relationship to ResistanceV=I∗RV = I * R, Where R is the resistance.I=V/RI = V/R

The Relationship: V, I, and R

Current and voltage are intimately linked. The relationship is defined by Ohm’s Law:

V/I=RV/I = R

Where:

  • V is the voltage (in Volts)
  • I is the current (in Amperes)
  • R is the resistance (in Ohms)

Ohm’s Law tells us that the current through a conductor is directly proportional to the voltage across it, provided the temperature and other physical conditions remain constant. This is a fundamental principle in electrical circuit analysis.