Will a conference paper submission have greater credibility if a teacher is a co-author? My lecturer is encouraging us to submit papers for a famous conference. He wants us to write the paper, show it to our teacher/him, bring it to a publishable condition, mention the teacher/him as the co-author and then submit it. I've seen some of my senior's papers published in journals with the teacher mentioned as the co-author.  

I've seen earlier questions about ethics and authorship when mentioning co-authors, but the basic question is whether a paper submitted to a conference would have greater credibility and a greater chance of being accepted, if a teacher or a renowned researcher is mentioned as a co-author? 

Assume the student is writing a paper for the first time, but does some diligent searching to figure out best practices for paper publications, prepares good test cases for experiments, and presents some findings very well in the research paper. Will the research be able to stand on its own merit and get accepted even if it is this one novice author? Does it really need an experienced co-author?

ps: This document says "Acting alone is a risky strategy, especially for those just out of graduate school. With seasoned coauthors, the probability of acceptance will likely more than double"

UPDATE: IEEE is clear on authorship:
IEEE considers individuals who meet all of the following criteria to be authors:
1. Made a significant intellectual contribution to the theoretical development, system or experimental design, prototype development, and/or the analysis and interpretation of data associated with the work contained in the article;
2. Contributed to drafting the article or reviewing and/or revising it for intellectual content;
3. Approved the final version of the article as accepted for publication, including references.  

Contributors who do not meet all of the above criteria may be included in the Acknowledgment section of the article. Omitting an author who contributed to your article or including a person who did not fulfill all of the above requirements is considered a breach of publishing ethics.
Authorship should not and, apart from inherent human bias, is not taken into consideration when evaluating a manuscript for publication. If the conference is reputable, you should trust that the committee will attempt to minimize this kind of bias by choosing equally reputable reviewers.

Rather, what you should be pondering is whether your department head has contributed sufficiently to the proccess for them to be granted authorship. Conventions vary by field: see this and this.