I am taking my first mircoelectronics course this semester and we are studying BJT's right now.

I am having a hard time wrapping my head around the whole concept of 'ouput resistance'. in theory it seems simple enough that

R_out = v_test / i_test

but i cant seem to apply it to problems. so i thought i would start with the basics.

would appreciate a lot if someone can help me with the following doubts :

1. in the hybrid-pi model of a BJT when we short the base and collector terminals what is the output resistance when looking into the collector and how ?

thank you for all the help

-ankit