Operational Amplifier

It works exactly the same way for DC as it does for AC.

Can you show us a circuit diagram, so that we can figure out what you mean.

An operational amplifier without negative feedback is a comparator.

Please explain more clearly. It could read that you have an op-amp with an ac supply. That'll be a dead'un.

It might be nice to know a little more detail. Here is a list of questions you could answer that will help:

• What Op-Amp part number? LM-741, OP-07, etc.
• What supply voltages are you using
• What DC output are you getting
• What DC gain do you expect? Why?
• What value and type of capacitors are you using?
• What value resistors are you using?

I gather this is still the Op-Amp as half wave rectifier project?

Need a LOT more information.

Circuit and component values would be a good start.

The open loop gain of an OP AMP is very large, which means that without feedback to reduce the gain to a useable level, the output is very unstable.

Adding to #6, that slight bias can drive the output to either extreme, when precise negative feedback is missing, as the native gain can be 1 million.

The question still smells like homework.

One last comment until a response from the OP provides us some feedback. There is always the possibility that what you have actually built is not what your schematic or working theory intended. A vast number of possible slips fit this category. A poor solder connection, solder bridge, defective part, wrong part are just a few of the common mistakes we've all made in this category.

ohk let me be more specific I am using opamp ic opa 4277 with 14 pin DIP.......I hv Connected +15VDC to pin 4 and -15VDC to pin 11.I hv not connected any ac input at any of the inverting or non inverting pin........now when i check the voltage at pin 1/7/8/14 which are output pins for each Op-amp I get +15VDC...i hv checked this with 2-3 ICs bt its the same..SO my question is whether the o/p am getting without AC input is correct or Theres some Problem? Sry for Brief question before.

Agreed, this is the normal expected behaviour

See the of an O.P amplifier,s carve (or the principle of an O.P AMP.) and study it carefully you will know why you got in the output the positive potential .