New Ad CTR
Suppose i make new ad in a older ad group which has already one ad. the CTR of new ad will be zero and may qs also will be low.
When google show this new ad for a search, it will not cost me more since it does not have any history.
Re: New Ad CTR
That's a really good question. Fortunately, it doesn't work like that.
First of all, quality score is calculated in real time when a search is performed that your ad is eligible to be displayed. Second of all, when there is no CTR data (and even when there is), Google will use various other "historical" data points like the average CTR of you competitors ads, your ad group quality score and indeed your account quality score. They'll even guess how your new ad is likely to perform.
In fact, I've noticed that since it's inception, AdWords will usually assign a decent baseline quality score to new keywords and ads based on the above historical data points. You are not at a disadvantage for testing new ads.