Which one of the following actions would make the maxima in the interference pattern from a grating move further apart? increasing the wavelength of the laser. increasing the frequency of the laser. decreasing the wavelength of the laser. decreasing the number of lines per length

are their multiple choices ?

explanation:

trig 15.3 cos

there are no contact forces mentioned on the list of choices that you've provided.

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.