is there is any external graphic card for laptops

USAFRet

Titan
Moderator
Well...there used to be. If the laptop has/had an ExpressCard slot, there are a couple of solutions that can do it. But that slot format was very short lived.
Supposedly there are a couple of Thunderbolt interface things coming online. But it will be 1. Expensive, 2. Not that great, or 3. Both.

But even if it is possible, then you're simply turning the laptop into an underpowered, non-portable desktop. You've removed the only advantage of having a laptop.