Relation between clustered and non clustered index......

1- when i rebuild my clustered index then will non clustered index be automatically rebuild or not? and why?

2- when i rebuild my Non clustered index then will clustered index be automatically rebuild or not? and why?

3- i craete a table with fixed row size 1004 bytes and insert thousands of rows in that, then create clustered and non clustered index on that table , then run dm_db_index_physical_stats DMV to get avg_fragmentation_in_percent and avg_fragment_size_in_pages ,then delete half of records from table (all records are row 2,4,6,8,10,....) such that i deleted half of records from each data pages...then again i ran that DMV... But it is still showing the same result .. Why?

Thanks in advance...