What is the output voltage in this circuit?

I would like to know the output voltage in this circuit at label A. (I am a beginner , sorry for stupid questions if any? )

The circuit setup is a sine wave source (ideal) in parallel with DC source series with a resistor.


-Devanand T

If it is an ideal source then the voltage at A will be the same sine wave without any level shifting....

what happens if the resistor is not there?

also what is the situation when sine wave source is not ideal?

DEV123 said:

what happens if the resistor is not there?

Click to expand...

Nothing

also what is the situation when sine wave source is not ideal?

Click to expand...

The sinewave source is considered formed by an ideal source in series with a resistor. And now its output is affected by the rest of the circuit.

sir i didn't understand it , can you explain in detail . Thanks

vinodstanur said:

If it is an ideal source then the voltage at A will be the same sine wave without any level shifting....

Click to expand...

Thankyou all for the replies

If the sinewave source is not ideal, ie if it have some internal resistance, then you can try to solve it by using the superposition theorem. Then you will get the exact voltage at point A.

It is simple, ie at first assume any one of the voltage source as zero and replace it with its internal resistance . Now find the current through the branch on which you are trying to measure the voltage. Then note the current and also it's direction. Then now consider the second voltage source and replace the first source with its internal resistance. Now find the second current.
Now add the two currents(by considering the direction too). Then find the voltage across the total resistance at that branch using V = IR. Now if the branch contains any voltage source, then add the result with that and you will get he voltage across the branch..............

---------- Post added at 16:31 ---------- Previous post was at 16:00 ----------

Okay, now you can try the circuit on any simulator. You will see the voltage at A will be a level shifted sine wave. In your case, if the internal resistance of the sinewave source increases, the sine wave at A will level shift upwards and when the internal resistance of sine wave source become equal to the external resistance + internal resistance of the DC source , then you could observe that the complete sine wave is shifted towards the positive Y axis. Now if you still increase the sine wave resistance, then you could see the sine wave component at the point A getting attenuated and dominated by the DC voltage. Finally if you makes the resistance of sine wave source to infinity, you could observe that the voltage at A is equal to the DC volt in the circuit....

So you can learn these things better by observing on a simulation ... If you don't have a simulator, then no need to go for big ones like proteus, multisim etc... Just check out this simple and great applet by falstad Circuit Simulator Applet .

Thanks vinod