Hi,
I am related to computer science field and want to undertake an internship in my field .can anybody knows what number of technical questions r asked in an internship interview.

It would vary depending on the company.

An Internship interview will vary greatly depending on the organization, as Wondergirl stated, however, I would suggest being proactive and preparing your thoughts on technical expertise you have which you can include in your own words during the interview.

Generally speaking, an Internship interview is used to determine if the candidate is mature enough to work in the professional atmosphere and is ready to do menial office and other types of tasks to aide the organization.

Yes, knowledge of the industry is important, but not as much as the attitude, work ethic and emotional maturity of the individual.