Answer:
Turn off battery supply → The electromagnet turns off.
Place a magnet care inside the coil of wire → The strength of the electromagnet increases.
Change the direction in which the current flows → The poles of the electromagnet reverses
Sorry but I can't understand your language
I'm pretty sure that it's b. That's assuming that you find the negative of b^2 and not the square of negative b.
Answer:
Step-by-step explanation:
