Four students in an auto mechanic shop were asked to design circuits for the headlights of a car. W, X and Y represents the three different bulbs they have to use. Their designs are shown below. Which circuit will be the brightest? (DOK 2)

unlike poles attract

force tends to be low and long diustance masses are high

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000

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.