Question

Why are electromagnets more useful than permanent magnets in many

modern technologies?
A. A power supply is not necessary to use an electromagnet.
B. Electromagnets can be turned on and off by controlling the
current.
C. Permanent magnets with the same strength are heavier.
D. The strength of the magnetic field is more consistent in
permanent magnets.

Answer 1

B. By controlling the current, electromagnets can be turned on and off

Answer 2

Answer: Electromagnets can be turned on and off by controlling the current

Step-by-step explanation: