An electric charge can produce an electric field around it. In this field range, it can interact with other charges. Charges of same sign will go away and opposite charges will come closer. The path of moving the charges due to electrostatic force or electric force is the electric field line. In this article, we are going to discuss the definition and properties of electric field lines with diagrams.
Contents in this article:
- Definition of electric field lines
- Physical significance of electric field lines
- Properties of electric field lines
- Drawing of electric field lines
- Why the two field lines do not intersect each other?
Definition of electric field lines
If we place a free unit positive charge in an electric field it will move due to electric force on the electric charge. If we join the different positions of the charge during its motion, we will get a line. This line is called the electric field line. One can observe the infinite number of field lines depending upon the initial positions of the charge. One cannot see the field lines in naked eyes because these lines are imaginary lines. The other name of the electric field line is the electric line of force.
Physical significance of electric line of force
Properties of electric field lines
Electric field lines have the following properties –
- Electric field lines are imaginary lines.
- Field lines are continuous lines.
- The tangent at any point on the electric field line gives the direction of the electric field at that point.
- Electric field lines start from the positive charge and end at the negative charge. That means electric field lines for a positive charge are outward and for a negative charge they are inward.
- No field lines intersect each other.
- Electric field lines intersect equipotential surfaces perpendicularly.
- These can be straight or curved lines. These lines are parallel straight lines for a uniform electric field.
- Electric field lines vanish inside the conductor. Because the electric field inside a conductor is zero.
Diagram of electric field lines
Electric field lines due to a single positive charge
Electric Field lines are outward from a single positive charge. It is assumed that the field lines start from this positive charge will end at the infinite.
Electric field lines due a single negative charge
The Electric Field lines are inward for a single negative charge. It is assumed that these field lines start at infinite and end at this negative charge.
Electric field lines for an electric dipole
Above figure shows the electric field lines for an electric dipole. As usual, electric field lines start from positive charge and end at negative charge.
Electric field lines for two positive charge
In this case, electric field lines are outward for both charges. There will be no field lines at the middle of the line joining the charges. Because at that point the net electric field is zero.
Drawing of Electric field lines due to two negative charge
Electric field lines for two negative charges are same as that for two positive charges. But all the field lines for both charges are inward in this case.
Why the electric field lines do not intersect each other?
We already know that the tangent at any point on the electric field line gives the direction of the electric field at that point. Now if two field lines intersect each other then we will get two tangents at the intersection point due to these two lines. So, in this case, two directions of the electric field can be observed at a single point. But the electric field at a point cannot have two directions. Therefore, two field lines cannot intersect each other.
This is all from this article. If you have any doubt on this topic you can ask me in the comment section.
- Electric field and electric field Intensity
- Electric charge
- Coulomb’s law of electrostatic force
- Properties of Magnetic field lines
- Gauss’s law of electrostatics