Effect of Current | Heating Effect, Magnetic Effect, Chemical Effect

The presence of electric current can be detected by the various effect of the current that it produces.

Effect of Current

There are 3 types of effects of current

1. Heating effect

2. Magnetic effect

3. Chemical effect

Download the pdf notes of Effect of Current Class 12 Physics

Heating Effect:

Current flows through a metallic wire due to the motion of free electrons. These electrons collide with the atoms of the metal and give some of their kinetic energy to these atoms.

As a result, it increases the kinetic energy of the vibrations of the atoms of the metal, ie, it generates heat in the wire. The heat ‘H’ produced by a current in the wire of resistance ‘R’ during the time ‘T’ is

Energy=qΔv= (it) (IR)

H=I²Rt

Uses of heating effect

• Electric heater
• Electric Kettles
• Toaster
• Electric iron etc.

Magnetic Effect:

When current flows in a straight wire, coil, or solenoid, a magnetic field is produced around them. The strength of the field depends on the value of the current and distance from the wire.

Uses of magnetic effect:

The magnetic effect is used in galvanometers to detect the current in Motors, fans, drill machines, grinders, etc use this effect.

Chemical Effect:

 Certain liquids like dilute H₂SO₄, and CuSO₄, in solution conduct electricity due to some chemical reactions that take place within them. This process is called Electrolysis

The chemical changes produced during the electrolysis of a liquid are due to the chemical effects of the current. It depends upon the nature of the liquid and the quantity of electricity passed through it.

Different terms used in electrolysis are

Electrolyte:

The liquid that conducts electric current is called an electrolyte.

Electrode:

The material in the form of wire, rod, or plate at which electric current enters or leaves the electrolyte is called the electrode

Anode:

The electrode connected to the positive terminal of the battery is called Anode.

Cathode:

The electrode connected with the negative terminal of the battery is called Cathode

Voltameter

The vessel containing the two electrodes and the liquid is called a Voltameter.

Working of voltameter

Consider CuSO₄ solution in a voltameter whose both electrodes are made of Cu.

Cu⁺⁺and SO₄^— are present in the solution. When current passes through the solution, Cu++ ions move towards the cathode and the following reaction takes place at the cathode

The Cu atoms thus formed are deposited on the cathode. The SO₄^— ions move towards the anode, take two Cu⁺⁺ from it and form CuSO₄, Following reaction takes place at the anode

As the process of electrolysis continues, copper is deposited on the cathode. At the same time, an equal amount of copper is dissolved into the solution from the anode keeping the density of the CuSO₄ solution constant.

Use of chemical effect

The process in which a thin layer of an expensive metal (gold, silver) is deposited on a cheap metal(iron) is called electroplating.

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