Consider the sodium vapor lamps described in question 13. how much energy is emitted by 45.8 mg of sodium atoms emitting light at this wavelength? assume each sodium atom emits one photon.

this would be about 43%

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.