Electric Dipole: Concepts and Applications
by Yuvi K - December 17, 2023
Electric Dipole: Concepts and Applications
Electric dipoles are among the most important elements in electronics and electrical engineering. The electric dipole is made up of two charges (+q and −q) placed equal distance apart, so that the vector from the negative charge to the positive charge makes an angle θ with a certain fixed direction. The dipole shown in the figure has a positive charge q at one end and a negative charge −q at the other end.
What is an Electric Dipole?
An electric dipole is a pair of electric charges of equal magnitude but opposite sign separated by a distance. Dipoles have a dipole moment vector, indicating the magnitude of the dipole and the direction along which it is pointing. A dipole moment vector can be represented as an arrow with its arrowhead pointing from the negative charge to the positive charge. The electrical force between two electric dipoles is inversely proportional to the square of the distance between them.
Characteristics of Electric Dipole
• The dipole moment (डाइपोल मोमेंट) of an electric dipole is equal to the product of the charge and the distance between the two charges. It has the dimension of electric charge multiplied by distance.
• The electric dipole has no net charge—the total charge of the electric dipole is zero.
• The two charges are equal in magnitude but opposite in sign.
• The dipole moment vector points from the negative charge to the positive charge and is expressed in units of Coulomb-meters ( कोलोंब-मीटर).
• If the separation between the charges increases, the dipole moment vector increases as well.
Applications of Electric Dipole
Electric dipoles are used in a variety of applications.
Electric Motors
Electric dipoles are used in electric motors to generate a rotational force. An electric motor consists of two electric dipoles placed near each other, with one being a permanent magnet and the other an electromagnet. When a current is applied to the electromagnet, the two dipoles interact and create a torque, which causes the motor to rotate.
Capacitors
Electric dipoles are also used in capacitors, which are devices used to store electric energy. Capacitors are made up of two metal plates separated by a dielectric material such as a sheet of paper or an air gap. When a voltage is applied across the plates, an electric field is formed and electric dipoles are created between the plates. These dipoles store energy, resulting in the capacitor’s ability to store electric energy.
Electric fields
Electric dipoles can be used to generate an electric field. When an electric dipole is placed in an electric field, the forces acting on the two charges cause the dipole to orient itself so that the dipole moment vector points along the direction of the electric field. This orientation results in a displacement of charge and an electric field is generated around the dipole.
Electric dipole radiation
Electric dipoles can also be used to generate electromagnetic radiation. When the electric dipole is placed in an oscillating electric field, it will oscillate and emit electromagnetic waves in all directions. This type of radiation is known as electric dipole radiation, and it can be used for a variety of applications, such as radio and television broadcasting.
Conclusion
Electric dipoles are essential components of electronic and electrical engineering. They are used in a variety of applications such as electric motors, capacitors and the generation of electric fields and electric dipole radiation. The electric dipole is composed of two equal charges of opposite sign separated by a distance, and the dipole moment is equal to the product of the charge and the distance between the two charges.
