yes kush, u can file H1b for part time work. But 40hr/week will make u a full time employee.

..excerpt from http://www.hooyou.com/h-1b/h1b_faq.html

17. Q: May I have a part-time H-1B? If I currently have H-1B
status from my full-time employer, is there anything I need to do?

A: Yes, you may have a part time H-1B.

A US employer may petition for a part-time H-1B for you. As long as
your work hours are at least 50% of the normal full time hours in your
industry and you satisfy all other requirements for an H-1B, you are
eligible to possess part-time H-1B status.

If you have H-1B status already, you can apply for a concurrent H-1B
for another part-time job. In this situation, there is no set number of
hours that the beneficiary must work for each employer. You should ask
the new prospective employer to apply for a part time H-1B visa on your
behalf. You may keep two or more concurrent H-1Bs.

Hope this helps...