EFFECTS OF ELECTRIC CURRENT

Prepared by:Touqeer Ahmed Jumani

Lecturer Electrical DepartmentMUCET Khairpur

HEATING EFFECT

When electric charges move through a wire, they lose some of the energy to the atoms in the wire. On receiving the energy, The atoms vibrate more and more causing the wire to heat up. Some of the Electric Energy is changed to heat energy. The higher the resistance the more the heat energy.The amount of heat generated is governed by Joule's first law: Q = I2·R·t In industry soldering, welding, cutting, drilling and working of electric furnaces are based on heating of electric current.

CHEMICAL EFFECTS

The passage of an electric current through a conducting liquid causes chemical reactions.The resulting effects are called chemical effects of electric current.Two major effects are:

1-ELECTROLYSISIn chemistry and manufacturing, electrolysis is a method of using a direct electric current (DC) to drive a chemical reaction.

Electrolysis is commercially highly important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell.

(2) ELECTROPLATING

The most common application of the chemical effect of electric current is electroplating.

In this process, there exists a liquid, usually called the electrolyte, through which current passes. Two electrodes, connected to the terminals of a battery with a switch in between, are inserted in the liquid.

Electroplating is done in industries to have an anti-reactive coating on the parts of machines so that they do not react with the raw material, to have an anti-corrosive coating for the machines so that they do not get corroded, and a heat-resistive coating for parts like boilers to resist the heat produced by the machinery. Gold plating is one of the most common applications of electroplating in ornament-making.

MAGNETIC EFFECTS

If a magnetic compass is placed near a conductor carrying current (wire), the needle is deflected. This shows that a conductor carrying current has a magnetic field around it.

The magnetic field around a current carrying straight conductor is in concentric circles. It can be observed by passing a current carrying straight conductor through a cardboard and sprinkling iron filings on it.

All motors, transformers, Alternators and most of the measuring electrical instruments use magnetic effect of electric current.