[quote=““Can i turn off my laptop’s screen while the monitor is on??””]

I would think about that option because i need big screen…

[/quote]

most certainly YES … a big screen will change your life! … do yourself a favour and get a decent expensive one … watching a movie on couch with color shift is no fun! … sitting infront of a too bright display (PWM dimming flickering) is killing me right now …
also, imagine : your lappy is always closed, connected to a big screen… you never turn it off, just let it hibernate … when you move the mouse it wakes up … this way you dont have to open the lid when powering it on (geek yay)