Pre-lab Question 2. Assuming the sample bill represents 29 days of service, and the customer consumed energy at a steady rate all month, what was the average power (or, in other words, rate of energy consumption) in kW?

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.