Three point charges are arranged on a line. charge q3=+5.00x10^-9c and is at the origin. charge q2=-3.00x10^-9c and is at x=+4.00cm. charge q1 is at x=+2.00cm. what is the magnitude and sign (+ or -) for q1 if the net force on q3 is zero?
a. 0.750 nc
b. 0.520 nc
c. 0.975 nc
d. 0.000 nc

A. 0.750 nC

Explanation:

It is given that net electric force at q3 is 0,

So electric field because of q1 at origin=  electric field because of q2 at origin

   =( -3.00x10^-9 x 2^2)/ 4^2

   =-0.750nC

It will have negative charge

the answer would be c

frequency or wavelenth of em radiation in a vacuum