Electric Dipole-

 

A system of two equal and opposite charges separated by a small distance is called as an electric dipole.

 

For example- two charges +q and -q separated by a small distance 2ℓ constitute an electric dipole.

 

 

Here,

• The distance (2ℓ) between the two charges is called as dipole length.
• The mid point of the line joining +q and -q charges is called as center of the electric dipole.

 

Charge On An Electric Dipole-

 

By additive nature of electric charge, we have-

 

Total charge on an electric dipole = +q + (-q) = 0

 

However, the charge on an electric dipole is equal to the magnitude of either charge of the electric dipole.

For example- If charge on an electric dipole is 5 µC, then one charge is +5 µC and the other charge is -5 µC.

 

Also Read- Properties of Electric Charge

 

Examples of Electric Dipoles-

 

The examples of electric dipoles are-

• Molecules of water (H₂O)
• Molecules of ammonia (NH₃)
• Molecules of hydrochloric acid (HCl)
• Molecules of carbon dioxide (CO₂)
• Molecules of sodium chloride (NaCl)
• Molecules of alcohol etc

 

Electric Dipole Moment-

 

Electric dipole moment of an electric dipole is defined as the product of the magnitude of either charge of the electric dipole and the dipole length.

 

It is a vector quantity having its direction from negative to positive charge. It is denoted by p.

 

 

Mathematically,

 

• The magnitude of electric dipole moment is p = q x 2ℓ.
• The direction of electric dipole moment is from negative to positive charge.
• The SI unit of electric dipole moment is coulomb meter (C m).
• The dimensional formula of electric dipole moment is [M⁰L¹T¹A¹].

 

Read the next article on-

Electric Field Due To Electric Dipole

 

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