I want to ask 2 questions about BJT.
1-How can i test a BJT whether it is defected or not?
2-How can i determine the type of the BJT (NPN or PNP)

 

You can forward bias the BE and BC junctions with a DMM. They both should read ~0.7V for silicon. Reverse biasing the BE and BC junctions should read ~3V. This is for an NPN. The reverse would be true for PNP.

 

The one lead that will conduct to both other leads is the base.

 

Thanks for your answers.