Question

If 1mC charge is located at origin then the force on that charge will be .........?

Answer 1

The electrostatic force between two point charges is given by Coulomb law:

$$\vec{F}=\frac{kq_1q_2}{r^3}\vec{r}$$

If the point charge is in the external electric field, then the force is:

$$\vec{F}=q\vec{E}$$

where $\vec{E}$ - electric field strength.

In our case, if the charge is 1mC, and it's located in the origin:

$$\vec{F}[N]=10^{-3}\vec{E}(0,0,0) [N/C]$$