[dba-SQLServer] Log file reuse

If a SQL Server action query completes, does SQL server reuse the now empty
log file?

I have a raid array that is huge and I use to hold these large databases.  I
have another single drive sitting on a SATA channel.  I am experimenting by
placing the log file onto that single SATA drive and the data file on the
raid.  I am running about 660 more action queries to move data from fields
in a 50 million record 680 field wide table to a 3 field wide table.  The
source table and the destination table both sit on the raid, with the log
file out on the non-raid.  I am hoping that because of IO issues, placing
the log file on a different physical drive will speed things up.  I have no
way to really know however.  

I am hoping that once the log file is expanded (it is about 13 g now) that
unless the data in the subsequent fields requires more log file room, the
"cost" of expanding the log file will go away and the log file empty space
will be reused for each subsequent action query.

John W. Colby
Colby Consulting
www.ColbyConsulting.com