Unable to hear a ringtone for incoming call when phone is off?

phone off, black off screen, and tucked away in my purse, I used to be able to hear incoming call ringtone, turn phone on, slide up screen, and answer phone. now can only hear incoming call ringtone if phone is on.

Seriously, if the phone is powered off, there is no way it's going to ring. Seriously, I can't believe this question was asked and more seriously, I can't believe I wasted my time answering it.

I think the OP means screen locked.