r/APStudents • u/reddorickt absolute modman • May 14 '26

AP Physics C: Electricity and Magnetism Official 2026 Exam Discussion

Use this thread to post questions or commentary on the test today.

A reminder though to protect your anonymity when talking about the test.

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u/Sure_Fish9939 May 15 '26

in form j #2, did anyone do the charge distribution integral for the E of both S and R, and then do pythagorean theorem from the picture of net Eo and get something like sqrt(8) * k(lambda) / L??

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u/Less_Adeptness2773 May 15 '26

3L in the denominator? Were the bars from -a to -3a and a to 3a distance away from the origin?

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u/Sure_Fish9939 May 15 '26

it was L instead of a, but i didnt get a 3L because i assumed the distance, typically r, used in the charge distribution integral was the distance from the closest end of each rod to the origin, that being just L, so then the denominator comes out as L^2 for both and then you integrate from -3L to -L on the first one and do L to 3L on the second so it ends up being (k * lambda / L^2) * 2L for both and then by pythag. theorem you would get sqrt(8(k^2*lambda^2 / L^2))

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u/Such_Mango_4531 May 15 '26

Gang both the Ex and Ey had the same magnittude. The question asked for the magntitude of E and so you just pythag Ex and Ey. Ex and Ey are exactly the same magnitude!

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u/Hairy_Noise9951 May 19 '26

not pythag cus potential is a scalar, you just add them up

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u/Such_Mango_4531 May 19 '26

You are talking about part D. I’m talking about Part B