In recent years it has been possible to buy a 1.0 f capacitor. this is an enormously large amount of capacitance. suppose you want to build a 1.0 hz oscillator with a 1.0 f capacitor. you have a spool of 0.35-mm-diameter wire and a 3.3-cm-diameter plastic cylinder. how long must your inductor be if you wrap it with 2 layers of closely spaced turns?

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge

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.