Electric Dipole Is Placed In A Uniform Electric Field

A dipole is a pair of equal and oppositely charged poles separated by a distance. Electromagnetism has two forms of dipoles, electric dipoles, and the other dipoles are magnetic dipoles. 

A dipole is measured in terms of its dipole moment. A dipole is formed as a result of the uneven sharing of electrons. An electric field is an area where the electric charges are present. In a uniform electric field, the current strength is the same at all points in the field. 

In this article, we will see what happens when an electric dipole is placed in a uniform electric field. We will also look into the connection between the electric dipole and uniform electric field. 

Electric Dipole – Definition

An electric dipole is a pair of equal and opposite charges with a uniform distance. The charges are represented by -q and +q. The direction of the electric dipole is from negative charge to positive charge. The distance between the dipole is represented by r, and the middle point of this separation is called the centre of the dipole. 

Imagine that two charges -q and +q of equal magnitude are separated by length d. This combination is called an electric dipole. The electric dipole is created by mixing these equal and opposite charges and the separation by a definite distance. 

An electric dipole is a vector quantity that has a definite negative to positive charge direction. This convention is only applicable to the dipole in Physics and not Chemistry. 

Electric Dipole Moment 

Dipole moment is the measurement of the separation of positive charge and negative charge in space. This is the benchmark of the system’s overall polarity. In other words, the dipole moment is the magnitude of any two charges and the length between the middles of the positive charge and the negative charge.

Dipole moment = Magnitude of charge x distance of separation of charges

It is measured in terms of Deby units. 

There is a dipole moment in that system where there is a separation of charges. Electric dipole plays a vital role in understanding the concept of polarisation. So electric dipole is prominent not only in physics but also in chemistry. In many molecules, the midpoint of the negative and positive charge coincides. These molecules with a permanent dipole moment as the centre of negative and positive charges that do not coincide are called polar molecules.

Electric Dipole – Direction

The direction of the electric dipole is always from negative charges into positive charges in a system. In an electric field, a dipole undergoes torque, and as a result of this torque, the dipole rotates, and its axis becomes aligned to the electric field direction. 

The torque is greater when the dipole is at right angles to the electric field. This is dependent on the factors like the distance between the charges, strength of the electric field, magnitude of the charges etc. The magnitude of the charges shows the amount of torque on dipoles. The dipole moment points to the direction of the electric field around it. 

This is because an electric dipole has the dimension of electric charge times displacement. 

What is the electric dipole in a uniform electric field? It is always zero, as the work done is zero.

What happens to an electric dipole when placed in a uniform electric field?

The electric dipole placed in a uniform electric field experiences a torque that makes the dipole align in a parallel position to the direction of the electric field, with a net force of zero. In this case, the negative and positive charges that comprise the dipole experience force are equal in magnitude and opposite in direction. 

The electric dipole is under the effect of the force produced by the two equal and opposite charges, and this gives rise to the torque on dipoles. On deriving the equation, we get the value of the angle as 90 degrees. The net force acting on dipoles placed in the uniform electric field is zero, as the forces on the negative and positive charges that constitute the dipole are equal and opposite. Thus, the net force acting on dipoles will also be zero. 

Conclusion

The electric dipole and uniform electric field are linked to each other. Electric dipole experiences tremendous changes when placed in a uniform electric field. When the electric dipole is placed in a uniform electric field, the dipole experiences a torque and aligns parallel to the electric field. The net force acting on dipoles is zero. 

An electric dipole moment measures the charge separation in a system and is measured by Deby units. There are so many factors that determine the dipole of a system. Those factors are charge, the distance between the two charges, their magnitude etc.