A: Hello.
B: Hello. May I speak to Mina?
A: This is she.
B: Hi, Mina. I am Jake.
A: Hi, Jake. What's up?
(Is the expressions 'I am Jake' correct in a telephone conversation? Do we have to use 'This is jake'?)
"This is Jake" or "I am Jake" -- either will work just fine.
=)