AC & DC Current

This lesson covers:

  1. The difference between 'alternating current' (AC) and 'direct current' (DC)
  2. How AC and DC differ when shown on current/time and voltage/time graphs

Which type of current periodically reverses its direction?

Direct current

Alternating current

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When charge always flows around a circuit in the same direction, we call it:

Alternating current

Direct current

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True or false? Alternating current is caused by an alternating potential difference.

True

False

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Graph showing alternating current waveform over time with positive and negative peaks.

The above graph could be for:

(Select all that apply)

Direct current

Direct voltage

Alternating current

Alternating voltage

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Direct current is supplied by:

(Select all that apply)

Batteries

Cells

The mains supply

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All countries use alternating current as their mains supply.


In the UK, the mains supply has a frequency of Hz, and a voltage of V.

50
230

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The role of an oscilloscope is to:

Power circuits

Display how voltage changes with time

Generate alternating current

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Graph showing a constant voltage over time representing DC current.

Which type of current would be generated from the supply shown in the diagram above?

Direct current

Alternating current 

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