I understand that a laptop is not grounded and bringing it in contact with certain surafces can cause static build up and shock when i touch a metallic component of laptop.
my question is how do i prevent it?
Laptop is asus k55vm it is placed on wooden surface by it's 4 rubber stands.
You can try to use a wire or a metallic strip on the wooden surface that is then connected to the ground or a metallic window frame.
Although , other than the static , I don't know or see the laptop giving out discharges like this if you're using the 3 Pin adapter that came along with the laptop.
It should basically not happen.
You might need to get it checked from the right people.
That's is a Pin that they must have given along with package. you can attach it back, if you can't find it, then you can get one at a hardware store or it the cable from the wall socket to the adapter is changeable, then you could get one with the three pins on.
if i get a 2 -3 pin converter will the earth work i mean must n't the 3rd pin be attached to the earth end of the socket of it to work ? i mean will the earthing work even if there is no 3rd pin in the adapter?
No, the earth will not work if the pin ain't there.
What you need is either a new 3 Pin cable to connect into the Adapter body if the present cable is detachable or then you need the pin in the old adapter that is missing.
Is it your wall socket or your laptop charger that is missing the grounding pin?
If all the wall sockets in your home don't have the 3rd pin, you have bigger concerns than just your laptop; as ungrounded appliances and other products have no way to discharge should an electrical failure occur inside. The 3rd pin is tied to the chassis so that if it comes into contact with the + or - voltage paths it gets discharged to ground rather than the first person who touches it. If you own the home, you may want to invest in updating the wiring (it will probably be rather expensive, but likely cheaper than a stay in the ER, and will help ensure your electronics don't fail prematurely); otherwise consider saying something to your landlord or finding a new place next lease period.
If it's just the outlet you are using, you can probably rewire the outlet to get it properly grounded.
If your charger is missing it's ground plug, call the company and complain, you probably won't be able to reconnect yourself if it fell out, because it requires a firm electrical connection.
US Wiring: One pin is Hot, One pin is Nuetral (common), and thrid pin (Round) is AC ground.
Hot is self explainatory, Has the 115 VAC (RMS).
Ground. Is tied to earth ground At the Home, ie tied to water pipe, or a seperate grounding rod.
Nuetral, or common. Is also tied to earth ground at some point.
When you look at a computer, You will find that both the "earth" Ground and the Muetral (common) are both tied to Chassie ground. If you reversed the Two pins at the outlet (wall plate) and plugged the computer PSU in, you would blow a House fuse. This is also true for may applianaces.
In the case of a laptop using a Power adaptor (brick), Three types - AC input. Two prong nonpolorized, two prong Polarized, and three prong. In all three cases the AC ground nor the AC nuetral are connected to the DC output (return side). Nor is the AC Ground and Common tied togeter internally in the adaptor. Therefore laptops are NOT grounded.
The adaptors contain no metal (conductive) outside casing, so no shock hazard.
The AC input is fed to a Transformer which steps the AC input down. This transformer also provides isolation so that the AC output is totally isolated from the AC input.
The output is (normally) around 19 VDC and not considered a Safty hazard.
Then comes the question of dischage to, or from, the laptop to an individual. this is normally a result of a Charge buildup on the individual -ESD, But does not have to be an individual. Example one individual ZAPPED a HDD by sitting it on a Glass plate, The glass plate had a charge buildup due to are flow espeacially if Relative Humidity is LOW (<30%).
Assumming this charge is before the AC adaptor is even plugged into the AC, then it depends on where the charge is building up, If it's on him, then discharging himself before picking up the laptop would solve the problem. If table then possibly sitting it on a conductive surface would be better.
If it only occures with the AC adaptor plugged in then I would guess a defective AC adaptor, with a short between the AC hot and the neg (common) output pin on the adaptor, But then that might tend to fry the laptop.