Two charges, $+4C$ and $+16C,$ are fixed $1m$ apart, with the second one to the right.

a$.$ Draw the correct magnitude and direction of the electric field lines between these

two charges.

b$.$ Calculate the magnitude and direction of the electric field halfway between the two.

c$.$ If a $-2nC$ charge is placed halfway between the two charges, what is the magnitude

and direction of the net force $($in $N)$ on this charge.

d$.$ Draw a force body diagram for this $2nC$ charge