Solenoid valve – electromagnetism

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

  • The solenoid
  • Magnetic flux, Φ
  • Magnetic flux density, B
  • Magnetomotive force, Fm
  • Field strength, H
  • Permeability, μ0 and μr




Problem statement

When AC power is distributed and used in an electrical power application there will usually be a monitoring system in place to detect any faults that will inevitably develop through prolonged, long-term use.

How can engineers use the characteristics of an AC circuit to detect when a fault condition has occurred?


Click the image to load solenoid valve. 

The above interactive allows you to demonstrate a practical design for a normally closed solonoid valve - no fluid flows unless action is taken.

Click the image to load magnetic fields interactive. 

The above interactive shows a bar magnet.  the slider lets you change the magnetic flux, while the button option "Flux density" draws three unit areas in different locations.


Click the image to load solenoid interactive. 

The above interactive allows you to explore how various factors affect the magnetic field strength, H, and the resulting magnetic flux density, B, of a single coil solenoid.

Supported by

  • Royal Academy of Engineering
  • Motorola Solutions Foundation