after factory reset can nexus get lollipop through ota? I use nexus 4 which got updated to lollipop on 27th Nov via ota . the thing is the phone got reset by mistake n it again came back to jellybean will it get the update again through ota ?? Or is there any other way? I don't knowto install it manually..
If your Current Rom Country (Or region) have Lollipop Update,
yes you can.
Else (Install manually) :

For find Frimware :

Where can I find stock or custom ROMs for my Android device?
Or download factory image : (developers.google)

How to Install :
( From android.stackexchange )


How to install Android 5.0 Lollipop on a Nexus 4
How to manually install Android Lollipop on a Nexus device