SAT Subject Physics Practice Question 75: Answer and Explanation
Which expresses the value of the electric field at the center of the square?
Correct Answer: A
2 A At the center of the square, the electric fields would all cancel. The contribution from the upper-left charge would point away from it, towards the lower-right charge, but the contribution from the lower-right charge would point exactly the opposite direction and cancel it. Likewise, the contributions from the lower-left and upper-right charges would cancel.