Question { Excel, 10906 }

Can't we write test plan without any document with us or we
definitely require the document for that

Answer

QA need proper planning.Hence with out proper SRS, Accurate
Test plan can never be determined. As QA is done based on
the proper documents.Improper documents leads to test plan
failure.So ask for proper documents before test planing.
Some time experience also fails.

Question { HCL, 7595 }

If there is non reproducible bug which developer is not
ready to agree, how you will convince him.

Answer

First thing, tester should always log a bug which is reproducible at his end as well as dev.
second case if it is reproducible at tester end and not reproducible at dev end. There may be build mismatch.
Third case if bug is occuring once in 100 times and unable to find the ways to reproduce then Screen shot should be taken and logged into the bugreport. If dev is unable to realise the technical thing involved in the bug then problem has to esculated to higer mgmt.