Which is a characteristic of electromagnet that make useful in simple tools, such as doorbell & hair dryers?
(B) they can't transmite electricity
(C) they can be switched on & off
(D) they can be made of plastic
Answer:
I would say c because even a weak magnet can be useful ie pocket rc cars(under two inches in size) use them to turn the wheels.
Gotta say C and maybe A. You don't need an epecially strong electromagnet for either of these (Not like the car lifter at the junkyard), but it's vital to be able to turn them on and off. The doorbell solenoid is only energized while your finger is pushing the button (Ding). When you shut it off by removing your finger, the spring pulls the plunger back (Dong).
I would say C. I cant imagine what a hair dryer would have an electromagnet in it for? A coil, yes, a magnet, no.
The answers post by the user, for information only, FunQA.com does not guarantee the right.
More Questions and Answers: