I am using google map API version-3 , I was trying with different zoom value, I have randomly done for some numbers started with 1 upto 100 , map gets zoom in for increasing
Google Maps basics
Zoom Level - zoom
0 - 19
0 lowest zoom (whole world)
19 highest zoom (individual buildings, if available) Retrieve current zoom level using mapObject.getZoom()
mapObject.getZoom()