Scaling Resolution with external monitor


I have an ordered a 12inch powerbook - I just wanted to clarify if I connect a 21 inch external monitor - would the resolution support increase from 1024? I have noticed this happening on a PC desktop where the graphic card support only 1024 on a 15 inch monitor but scaled up to 1280 with a 17 inch.

Has anyone tried this? Please advice.


From the PowerBook 12" tech specs:
"Dual display and video mirroring: Simultaneously supports up to 1024 x 768 pixels on the built-in display and up to 2048 x 1536 pixels on an external display, both at millions of colors"