Does nbr jars in classpath make a difference

[timasmith]

Suppose I create a large app with 20 packages, each a large set of
Swing UI code, client functionality etc.

Is there are penalty to having all the code in one jar (say 100Mb jar
file) versus 20 5 MB jar files?

Is memory consumption a lot lower if each package is its own
application without dependencies on the other jar files? Such that the
user is running one 5 MB jar instead above 20 or 1 100MB jar file?

thanks

Tim