Physics » Magnetism and Faraday's Law » Alternating Current

Alternating Current

Alternating current

Most students learning about electricity begin with what is known as direct current (DC), which is electricity flowing in one direction only. DC is the kind of electricity made by a battery, with definite positive and negative terminals.

However, we have seen that the electricity produced by some generators constantly alternates (switches direction) and is therefore known as alternating current (AC). There are a number of advantages to AC current, the main advantage to AC is that the voltage can be changed using transformers. That means that the voltage can be “stepped up” at power stations to a very high voltage so that electrical energy can be transmitted along power lines at low current and therefore experience low energy loss due to heating. The voltage can then be stepped down for use in buildings and street lights.

A list of the advantages of AC current:

  • Easy to be transformed (step up or step down using a transformer).
  • Easier to convert from AC to DC than from DC to AC.
  • Easier to generate.
  • It can be transmitted at high voltage and low current over long distances with less energy lost.
  • High frequency used in AC makes it suitable for motors.


In Nigeria, alternating current is generated at a frequency of \(\text{50}\) \(\text{Hz}\).

The circuit symbol for alternating current is:


[Attributions and Licenses]

This is a lesson from the tutorial, Magnetism and Faraday's Law and you are encouraged to log in or register, so that you can track your progress.

Log In

Share Thoughts