I read somewhere that DC and AC should not be connected in parallel.
Question #1
In below common emitter circuit is Vin parallel to Vcc?
Question #2
Assuming C1 is not there (blocker for DC circuit),
Vcc = 5V
R1 = R2 = 10K
Voltage divider value at R1 and R2 is 2.5V
What should be Vin range assuming peak voltage of 1V:
a) 2.5V +- 1V ( 1.5V - 2.5V - 3.V)
b) 0 +- 1V (-1V - 0V - 1V)
I am trying to understand if A/C voltage source has to match voltage divider voltage which is 2.5V in our example.

 

I read somewhere that DC and AC should not be connected in parallel.
Question #1
In below common emitter circuit is Vin parallel to Vcc?
Question #2
Assuming C1 is not there (blocker for DC circuit),

#0. Perhaps the statement is taken out of context.
#1. No. Vin is in parallel with VB. (after series C1)
#2. Makes no sense. You must leave C1 in place. The purpose of C1 is so that Vin does not interfere with VB DC bias.

 

You need to look up the definition of "parallel" as pertains to circuits.