What is the smallest amount of electricity (volts, amps?) required in order to create a magnet capable of spinning a 50 grams steel object 150,000 - 200,000 rounds per minute (rpm)? Phrased another way: What is the smallest electrical engine capable of doing that at the present? 50 grams might not seem like much, but it is when it comes to spinning it 200,000 rpm. This is not for homework; instead, I'm just curious about what is going on with our latest technology at the present.