Question

Find the electric potential at the centre of the square of side 1m at the four corners of charges of q1, q2,q3,and q4 are placed having values 3×10^-8C,-3×10^-8C,-5×10^-8C and 6×10^-8C respectively.

Answer 1

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/mulpoi.html

Answer 2

Remember, they asked for the potential (voltage) not the E field, so there is no need to do vectors, just add and subtract potential scalars.

Answer 3

I got 127.26 C-m
Please check the answer is correct or not

Answer 4

distance from center to each charge = (1/2) of diagonal = (1/2)sqrt(2) = .707 meter
so k/r for each charge = 1.27*10^10
so
V = 1.27*10^10 [ 0 + 6*10^-8 - 5*10^-8 ] note the first two cancel
= 1.27 *10^2 = 127 volts, agree

Answer 5

Thankyou