AC characteristics and AC waveform addition

How to use this resource

Please download the PDF of this resource using the Download PDF link in the banner above.

Below are a series of interactives which support the resource. Each interactive can be launched by clicking on its image, or through links in the PDF itself.

Some resources have pre-requisites; where this is the case, you'll be able to access any required resources through the Pre-requisites section.

Topic areas

Electrical and electronic engineering

  • Voltmeter
  • Sinusoidal and non-sinusoidal waveforms
  • Amplitude
  • Time period
  • Frequency
  • Instantaneous values
  • Peak value
  • Peak-to-peak value
  • Average value
  • Root mean square (rms) value
  • Form factor
  • Phase angle
  • Combining waveforms


  • Square and square roots
  • Basic arithmetic



Problem statement

AC waveforms are common in engineering and are found in a wide range of applications such as AC power delivery, instrument measurements, control signals and audio applications. Periodic AC waveforms can be characterised by a number of key parameters that allow an engineer to produce effective designs that work with them.

Additionally, AC waveforms can be manipulated and added to produce new waveforms, a process that can be used to produce active noise cancellation that can protect the ears from noisy plants or prevent external sounds from detracting from spoken instructions or music sent to headphones.

How can AC signals be characterised and added and how can these be useful?


Click the image to load AC meters. 

AC meters

The above interactive can be used to simulate the possible meter and waveform combinations stated in the resource.

Click the image to load AC waveforms. 

The above interactive can be used to investigate the properties of waveforms and compare how they change when the waveform changes, or when waveform properties change, such as period and amplitude. 

Click the image to load AC addition. 

AC addition

The above interactive can be used to investigate the addition of two identically shaped waveforms of different amplitutes and with different phase angles.

Supported by

  • Royal Academy of Engineering
  • Motorola Solutions Foundation