Point charges in plane

Electricity and Magnetism Level 2

As shown above, two point charges \(A\) and \(B\) are fixed on the \(x\)-axis with an equal distance of \(d\) from the origin \(O.\) \(A\) is charged negatively, while \(B\) is charged positively. The quantities of the electric charges on \(A\) and \(B\) are the same. The distances between the origin \(O\) and the two points \(P\) and \(Q\) on the \(y\)-axis are also the same, which is \(d.\) Which of the following is correct?

a) The electric field intensities at \(P\) and \(Q\) are the same.

b) The direction of the electric field at \(O\) is the \(-x\) direction.

c) If we move the point charge \(A\) to \(O\), then the directions of the electric fields at \(P\) and \(Q\) are the same.

Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, conceptual quizzes.

Our wiki is made for math and science

Master advanced concepts through explanations, examples, and problems from the community.

Used and loved by 4 million people

Learn from a vibrant community of students and enthusiasts, including olympiad champions, researchers, and professionals.