Swane :
i plugged it in the same socket and it didn't gave me a shock.
my adapter sparked(at the connection of the socket and the adapter) once but it was in a different socket and it sparked even when i plugged my tablet in there.
and if the problem is in the adapter will i be able to purchase it in a computer store or i need to purchase it at the manufacturer?
Where are you from? because sometimes by inserting the plug the other way around the phenomenon dissapears (it swaps the Live with the Neutral lines). For example, in US, UK, Switzerland etc, you have one single way to connect the AC plug in the wall socket, while in the rest of Europe you can revert the AC plug into the socket (and it is quite dangerous if the grounding connection is not OK).
Regarding sparking: it is normal and is generated by the auto-induction phenomenon (lamps, electrical ovens and motors) and/or the charging of the main capacitors (power supplies). It is NOT normal though to continue AFTER the plug is inserted in the wall socket.
If you must change the AC adapter, it is best to contact DELL representatives for your country and (hopefully) they will recommend you the nearest authorized computer shop.