The battery for a certain cell phone is rated at 3.70 V. According to the manufacturer it can produce 2.35×104J of electrical energy, enough for 5.75 h of operation, before needing to be recharged. find the average current that this cell phone draws when turned on.

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.