Properties Of Electric Field Lines

A field line is a locus that experts define by a vector field and a starting location. The electric fields are associated with electric field lines. There are many properties of these lines. The most important property is that the field lines never intersect each other. 

The discovery of the concept of electric field lines is attributed to Michael Faraday. Since the field lines are perpendicular to the surface of the charge, it helped him visualise the electric field using intuition instead of depending on mathematical analysis. Keep on reading more about these lines to understand why the field lines never intersect each other.

Understanding an electric field and its lines

An electric field or electrostatic field refers to the region around an electric charge in which the action of electric force takes place. Experts also refer to this electric force as stress. Huge stress may be created around the region if the charge magnitude is large. 

This field is represented by the symbol E while its SI unit is Newton per Coulomb.  This is equal to volts per metre.

An electric field can be represented by imaginary lines of force. These imaginary lines are known as electric field lines. When the charge is positive, the electric field lines come out of the charge. In contrast, when the charge is negative, the electric field lines move towards the charge. Moreover, the field lines never intersect each other. Also, the magnitude of charge and the number of field lines are proportional to each other.

Why do the field lines never intersect each other?

An important point to note is that a tangent at any point on a field line reveals the direction of the electric field at that point. Now if the intersection of the two field lines takes place, then there would be two tangents. These tangents are at the intersection point because of these two lines. 

Therefore, in such a situation, one can observe the two directions of the electric field at a single point. However, the electric field cannot have two directions at a particular point. Therefore, the field lines never intersect each other.

Types of electric field

Electric fields can be classified into two types: 

Uniform electric field:

The uniform electric field is one that is constant at every point. Experts obtain such a field by placing two conductors parallel to each other. They also ensure that the potential difference between them at every point turns out to be the same.

Non-uniform electric field:

The non-uniform electric field is one that is irregular at every point. This field is characterised by having different magnitudes and directions.

Properties of electric field lines

Here are the various properties of electric field lines:

• They start from a positive charge.
• These lines end on a negative charge.
• The movement of electric field lines is away from the positive electric charge.
• The movement of electric field lines is towards the negative electric charge.
• A tangent can be drawn at any point on an electric field line, thereby providing the direction of the field at that point.
• The electric field can never have two directions at a particular point. Consequently, the field lines never intersect each other.
• The magnitude of charge and the number of field lines are proportional to each other.
• Electric field lines enter or exit a charged surface in a normal manner.
• The field lines are uniformly spaced, parallel, and straight in a uniform electric field.
• The field lines are perpendicular to the surface of the charge.

• It is not possible for electric field lines to go through a conductor. As such, inside a conductor, the electric field is always equal to zero.
• Electric field lines can be affected by the force of attraction between two objects that are oppositely charged. Due to this, they tend to contract in length.
• The electric field lines are continuous curves in a region that is charge-free.
• The expansion of the electric lines of force tends to happen laterally. This means that these lines tend to separate from each other in a direction that is perpendicular to their lengths. The reason for this is the presence of a force of repulsion between charges.

Conclusion

Electric fields are associated with electric field lines. The most important property of these lines is that the field lines never intersect each other. An electric field refers to the region around an electric charge in which the action of electric force takes place. Its symbol is E while its SI unit is Newton per coulomb. It is not possible for an electric field to have two directions at a particular point. As such, the field lines never intersect each other. The two types of electric fields are uniform electric fields and non-uniform electric fields.