dear sirs,
i am new to this forum. i have downloaded the logicsim simulator. where can i get the basic logic circuits problems for practicing? pl. help me sirs. thanking you in advance.

Charu

 

You'll find a lot on google.
example:
http://www.cimt.plymouth.ac.uk/projects/mepres/alevel/discrete_ch11.pdf

There are also exercises under "Digital Circuits" here:http://www.allaboutcircuits.com/worksheets/index.html

 

For some easy introductory exercises, try using NAND gates to duplicate the functionality of the other basic logic gates:
NOT (inverter)
AND
OR
NOR
XOR
XNOR

Then, try doing the same thing using only NOR gates; but substitute NAND for NOR in the list of the other gates.

This is a valuable exercise. If you really "get stuck", you can search Wikipedia for NAND logic and NOR logic, but try to accomplish the objectives without peeking; you will learn much more that way.