The purpose of electric field lines is to visually represent the direction and strength of an electric field in a given region. They can help us understand how electric charges interact with each other and how they move in an electric field.
Electric field lines are drawn by placing a positive test charge in a given region and then drawing lines that show the direction that the test charge would move in the presence of an electric field. The lines are drawn closer together in regions of stronger electric field and farther apart in regions of weaker electric field.
Electric field lines have many practical applications, such as in the design of electronic circuits and devices, in understanding the behavior of lightning and other atmospheric phenomena, and in medical imaging techniques like electrocardiography and electroencephalography.
No, electric field lines cannot intersect. This is because at the point of intersection, there would be two different directions for the electric field, which is not physically possible. Therefore, electric field lines always repel each other and never cross.
The strength of an electric field can be calculated by measuring the distance between electric field lines, known as the electric field line density. The closer the lines are together, the stronger the electric field. Additionally, the number of lines originating from a source charge can also indicate the strength of the electric field, with more lines representing a stronger field.