Determine the direction of the electric field due to each charge at point P.

Step 1: Determine the direction of the electric field due to each charge at point P.
The electric field strength $E$ due to a point charge $q$ is given by $E = \frac{k|q|}{r^2}$, where $k$ is Coulomb's constant and $r$ is the distance from the charge to the point.

• Charge X is $+Q$. Electric field lines point away from positive charges. Since P is to the right of X, the electric field $E_X$ at P due to X will point from X towards P. From the diagram, this means $E_X$ points upwards and to the right.
• Charge Y is $-2Q$. Electric field lines