Does your estimated ∆ explain the variations seen in the wavelength and R calculations? Change the angle by 0.2° and recalculate the wavelength and R for one of your values. Comment on the changes you find.

good looking response

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.