Answer:
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
[tex]k\frac{q_{1} }{r_{1} ^{2} } =k\frac{q_{2} }{r_{2} ^{2} }[/tex]
[tex]\frac{q_{1} }{r_{1} ^{2} } =\frac{q_{2} }{r_{2} ^{2} }[/tex]
[tex]{q_{1} } } =\frac{q_{2} }{r_{2} ^{2} }*{r_{1} ^{2}[/tex]
=( -3.00x10^-9 x 2^2)/ 4^2
=-0.750nC
It will have negative charge
