Why does the moon have more impact craters than the earth?

Why does the Moon have so many craters compared to the Earth? Unlike the Earth, the Moon has no atmosphere to protect itself from impacting bodies. It also has very little geologic activity (like volcanoes) or weathering (from wind or rain) so craters remain intact from billions of years.

answercollision;

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.