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AC vs DC: Understanding the Key Differences

ac dc alternating current direct current current

This article compares AC (Alternating Current) and DC (Direct Current), outlining their fundamental differences.

AC | Alternating Current

AC stands for Alternating Current. In AC, the magnitude of the current varies over time, typically following a sinusoidal waveform. This means the electrons flow first in one direction and then in the opposite direction, effectively alternating their flow.

Examples:

  • Electricity mains supply is a sine wave AC.
  • Electric heaters and lamps can operate on either AC or DC. However, devices like radios and TVs require DC for signal processing and battery charging.

AC vs DC

DC | Direct Current

DC stands for Direct Current. In DC, the magnitude of the current remains constant over time. Unlike AC, electrons in a DC circuit flow in only one direction.

Examples:

  • Cells and batteries produce DC voltages and currents.

AC vs DC: A Detailed Comparison

The following table summarizes the key differences between AC and DC:

FeaturesACDC
Full formAlternating currentDirect current
Electric charge directionCharge or current changes direction periodicallyCharge or current flows in one direction only
Travel distanceIt is safe to transfer AC over long distances.It can not be trasmitted over long distances due to loss of energy.
FrequencyAC frequency varies as per country, in india it is 50 Hz and in US it is 60Hz.It is zero for DC.
Current magnitudeVaries with timeconstant
SourceAC generator or AC mainsCell or battery
Resistive parametersImpedance resistive onlyresistive only
Power FactorIt lies between 0 and 1It is always one.