How to erase a hard-disk with a magnet?

Question

I know one sure way of erasing data off a hard-disk is to wave a magnet over it but how exactly?
1. Does the hard-disk need to be powered on?
2. Secondly, does the magnet need to be in physical contact with the hard-disk?
3. Thirdly, how powerful should the magnet be?
4. Fourthly, if other components of the computer 'feel' the magnetic field (and they shall if the hard-disk is still in the computer), would they be damaged?

Answer 1

1. Not necessarily, but if it's on you'll need a less powerful magnet.

2. No, if the magnet is strong enough and is held within three inches of the disk, it'll be quite effective.

3. The more powerful, the better.

4. Most likely yes. Many components in a computer case are suceptible to magnetic fields. You'd likely destroy the CPU, RAM, hard drive, and possibly any CD or DVD drives.

As a final note, I would highly suggest to NOT do this to someone as a prank or for revenge. Aside from the fact that it can be considered as vandalism, the hard drive and any other components will not be reusable at all after it's done. The entire system would be a paperweight.

Answer 2

The magnet interior the NMR is a superconductor - there is not any source of the present, there is entirely a loop of steel, and contemporary is circulating by using it (it has no resistance). So there is not any way a thank you to music-down the sector. i actually discourage you to pass close to the magnet with something made out of steel. This magnet is better than you could think of...

Answer 3

Try this instead, it's free and fantastic: