Code:
SQL> connect sys as sysdba
Enter password: *********
Connected.
SQL> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP
------------------------------ ----- -----
SYS                            TRUE  TRUE
SANJAY                         TRUE  FALSE

SQL> create user test identified by test;

User created.

SQL> grant sysdba to test;

Grant succeeded.

SQL> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP
------------------------------ ----- -----
SYS                            TRUE  TRUE
SANJAY                         TRUE  FALSE
TEST                           TRUE  FALSE

SQL> conn test as sysdba
Enter password: ****
Connected.
SQL> conn test/test
ERROR:
ORA-01045: user TEST lacks CREATE SESSION privilege; logon denied


Warning: You are no longer connected to ORACLE.
SQL> conn sys as sysdba
Enter password: *********
Connected.
SQL> grant connect, resource to test;

Grant succeeded.

SQL> conn test/test
Connected.
SQL>