You are given a cylinder of outer radius 3.27 cm and length of 11.5 cm. along the axis of the cylinder is a hole of diameter 2.47 cm. find the volume of this cylindrical shell.

c, 1a hope this

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.