PostgreSQL CHARACTER VARYING vs CHARACTER VARYING (Length)

Is there any impact of using the character varying without providing the
length while creating tables?
I have created two tables and inserted 1M records. But I don't see any
difference in pg_class. (size, relpage)

create table test_1(name varchar);
create table test_2(name varchar(50));

insert into test_1 ... 10M records
insert into test_2 ... 10M records

vacuum (full,analyze) db_size_test_1;
vacuum (full,analyze) db_size_test_2;

Which option is recommended?

*Regards,*
*Rajin *