When a charge q is placed at a certain point in an electric field, it experiences a force toward the west of magnitude F. If instead a change 2q were placed at that same point what force would it experience?

If instead a charge 2q were placed at that same point the force will be 2F.

Explanation:

The electric force is equal to:

   (1)

Where:

F: is the electric force

q: is the charge

E: is the electric field

We can see that in equation (1) the electric force (F) is proportional to the charge q, thus, if now the charge it's the double (2q) then the force will be the double too:    

Initially:

Now,

Therefore, if instead a charge 2q were placed at that same point the force will be 2F.

I hope it helps you!            

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.