Acceleration can be defined as the rate at which velocity
Answer here

Acceleration can be defined as the rate at which velocity increases per second.

Assuming that the acceleration unit is

m/s^2

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary 

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.