When a simple magnifying glass is used properly, the image will be formed
a. at the focal point of the lens.
b. just inside the focal length of the lens.
c. about 500 millimeters behind the lens.
d. about 250 millimeters in front of the lens.

Magnifying glasses typically use a value of 0.25 meters, or 250 millimeters, distance. This means that that D is the correct answer and the image will be formed approximately D. 250 millimeters in front of the lens

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.