Electric Field Magnitude Ranking for a Dipole

Q16. The electric field lines of a pair of charges with equal and opposite magnitude are shown in the figure below. Sort the points A, B, C in the figure from the largest to the smallest magnitude of electric field.

Background

Topic: Electric Field Lines and Magnitude

This question tests your understanding of how the magnitude of the electric field varies in the vicinity of a dipole (a pair of equal and opposite charges). The density of field lines indicates the strength of the electric field at a given point.

Key Terms and Concepts:

• Electric Field Lines: The direction of the field at any point is tangent to the field line at that point. The closer the lines, the stronger the field.

• Dipole: A system of two equal and opposite charges separated by a distance.

• Field Magnitude: The electric field is strongest where the field lines are most densely packed.

Step-by-Step Guidance

1. Examine the diagram and locate points A, B, and C relative to the charges and the field lines.

2. Recall that the electric field is strongest where the field lines are closest together. Identify which point is in a region with the highest density of field lines.

3. Compare the spacing of the field lines at each point. The point with the most lines passing through a small area has the largest field magnitude.

4. Rank the points from largest to smallest electric field magnitude based on your observations.

Try solving on your own before revealing the answer!

Final Answer: B > A > C

Point B is closest to the charge and in a region where the field lines are densest, so it has the largest field. Point A is next, and point C is in a region with the sparsest field lines, so it has the smallest field.