Pulling one of the balls away from the other. to pull a ball away, click on the ball and drag it. what happens to the force arrows between the two balls? what does this mean in terms of gravity?

On Plato.

When the distance between the balls increases, the size of the arrows decreases. This shows that the gravitational pull between the balls also decreases.

Explanation:

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.