How do components get physically damaged when unplugging it?

[rifow11]

I have searched and found very "general" answers. I just want to know how does a computer get physically damaged by unplugging it while it is turned on.

What happens to the circuits and how did that happen? Does the computer get a short circuit and how?

 

[JRAtk94]

I think it is to do with the fact that the PSU suddenly discharges it's current load into the components when unplugged - I am really not sure about this though - it's just a guess.

Either way, don't do it.

 

[johnnyq1233]

I wouldn't say they get damaged as in fried. What I would say is that the HDD is always being written to and read from as the system is running.
So, if you pull the plug or if the power should fail as in blackout. There is a good chance that data will be lost or corrupted and your system might not boot after.
This is why a good Uninterruptable Power Supply is always a good thing to have around. It gives your system enough power to do a proper shut down, should the AC go down.
Hope this helps... JQ