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NUE 052 - Effects of Current

Electric current causes a number of effects. The four major effects are:
  • heating
  • magnetism
  • chemical
  • physiological
When current flows in a conductor, heat is produced. This heat is produced because of the resistance of the conductor. The higher the resistance the greater the heat produced.
This heating effect is used in:
  • electric stoves
  • electric radiators
  • electric kettles
  • electric cooking appliances
Another useful effect of electric current is the magnet effect. This effect is probably the most useful of the common effects. There are many uses such as electric motors and electrical appliances.
Some other magnet effects are:
  • TV
  • Radio
  • Transformers
  • Relays
  • Floppy disks
Current will flow in an electrolyte solution such as salt water. If two copper electrodes are placed in an electrolyte, current will flow through the liquid. This effect can be used in electroplating to coat a metal object such as a car bumper bar.
Electrodes in electrolyte
Other examples of chemical effect are:
  • battery charging
  • electrolysis
The physiological effect is the result of current passing through a living being such as a human. The obvious effect from this is an electric shock. An electric shock can cause severe burns or even death.
Electric shock
Some uses for the physiological effect are:
  • cattle prods
  • electric fences
  • defibrillators
  • electric chair

Effects of an electric current passing through a body



up to 2mA

hardly noticeable

2mA to 8mA

tingling sensation becoming painful

8mA to 12mA

muscle spasms and pain

12mA to 20mA loss of control of muscles, gripping of conductor
20mA to 50mA breathing can stop
50mA to 100mA heart may stop
100mA to 200mA heart will stop
above 200mA severe burning
Practice Tests Practice tests are available on the Practice Test page

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