I think their is not limit to prepare your PPC Ads

[DELETED]

It's really up to you, I don't think there is a limitation. You can always do trial and error for your ads, and go with the one that clicks.

If you're talking Adwords, you can have up to 50 ads per group if I recall correctly. These are active, inactive and deleted ads.

You should not test more than two active ads at a time. More than that simply waters down your test. The more ads, the more meaningless the test.