Important FAQ'S for Youtube Channels with less than 10K Views !!

FAQ'S -1: my views are less than 10k , do i need to again apply for adsense approval and monitization.

2 : my page views in adsense is not showing but in youtube analytics it is showing views why ?

3: my monitization is enabled but ads are not showing on my videos from april 2017.

4: will i gey my previous earnings before 10k