Just curious that, If I add more number of tags to a question (of course relevant and max of 5 tags), do I increase the number of viewers so that I can get good quality or more number of answers. Rather than looking for an answer to a question(either posted by me or someone else) with a single tag.
Potentially and in general, yes - more tags == more people.
Many people have set specific tags as favourite and these are the tags they would normally visit when looking and answering questions.
However, the main benefit of more tags is that it tends to focus the scope of the question on the listings - people can see more clearly whether the question is something they can or cannot answer. Adding more tags tends to mean better qualified people looking into the question.
Editing your title illustrates the importance of a good title in attracting views from potential answerers. Whether more tags or an improved title is a better use of time for gaining views (esp. from users who can potentially answer) depends on the volume of questions at a site.
Meta.StackOverflow is both a meta discussion site for StackOverflow and a StackExchange meta-meta discussion, but even so the volume of questions is fairly low. In this case improving the title (once the basic required tags are set) seems the better strategy.
StackOverflow has such a firehose of questions posted that tags are vital for me to find a seam of interesting ones that I can answer. (I have four "favorite" tags.) However at Math.SE new questions don't scroll quite so fast, and although I might set a favorite tag there, it isn't as important as a good title in attracting my viewership.
It occurs to me that on a given site one might try to quantify this (per @EmilVikström) by checking the average number of favorite tags of users with many recent answers. It doesn't strike me as an easy query to do with data explorer, but others may have better skills.