Answers

2016-02-26T22:14:30+05:30
There is plano convex, and bi- convex. 
The term "convex" is commonly used (even if incorrectly), to denote a bi- convex lens. Any other arrangement needs to be more explicit, e.g. plano- concave, plano- convex, bi- concave, concavo- convex, etc.
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2016-02-26T22:21:18+05:30
'nothing' both are same .. names r different...
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