Hello everyone,

I am struggling with the highlighted homework question #9.40, I attempted to answer it already and failed. My professor says the answer is 20.5mv, and is giving me an opportunity to figure out how he calculated it. if anyone can help with this would be strongly appreciated.

 

The picture of the question is kinda fuzzy and I can't read it completely. Can you help us out by showing your attempt at a solution, even though you think it may be wrong?

 

The hints are in the text, temperature, resistance, and something about 10 mv. Try to describe their effects, one at a time, and we might spot your error.

 

This is the formula for dc output error voltage I followed, and I just can't fathom how he is calculating 20.5mv

 

Hi,

If you apply the 10mv to the non inverting input, the gain is 2, so that gives you 20mv.
The error due to temperature is 10uv times 50, which is 500uv or 0.5mv.
20mv+0.5mv=20.5mv.
That appears to be the way he is doing it.

Also, here is a slightly better drawing...

 

That is the only way I can see it, thanks for the guidance sir....