Can a non-inverting op-amp circuit have Rf=Ri = 0? And what is its purpose?

[Anabelle37]

Homework Statement

How does a non-inverting op-amp circuit work?

What happens if you make a non-inverting amplifier with Rf=Ri = 0? What would be the
purpose of such a circuit?

 

[fss]

What is confusing you about a non-inverting op-amp?

http://en.wikipedia.org/wiki/Operational_amplifier_applications#Non-inverting_amplifier

If R1 = R2 = 0, there would not be much point as the gain would be 1...

 

[Mindscrape]

Yes, there is a point to having R1=R2=0! You can isolate a part of a system that might need to have a certain impedance by placing a voltage buffer (sometimes also called a voltage follower) in the circuit.

As far as how the non-inverting amplifier works, do a node-voltage analysis using ideal op-amp rules. This is one of the simplest amplifiers to solve, so you ought to know how to do it.