Hello, i have been recently learning about wheat stone bridge circuits, i am completing an online course, however, i only get 3 attempts at each question, i have completed them all and got them all correct apart from one, which i really don't understand, i am not looking for the answer here as i would like to work it out my self, but is there an equation to go with this as we haven't been taught any and i have had to find them on the internet.

thanks.

the question is attached
i have tried a few equations i found on line and got the answer 666.6v a few times but this is not correct, any help would be greatly appreciated
thanks

 

Ok, But can you show us your attempt to the problem?

 

Think of R1 / R3 as a voltage divider. Carry on.

 

The question is incomplete.

In order to get the peak output amplitude to a particular value by adjusting the gain, you need to what the peak input amplitude is. You aren't given that. You know only how much R1 changes per microstrain, but you aren't told what the peak microstrain is that R1 is subjected to.

It appears that the information that is needed is developed in the course of answering parts (i) through (iii) of the question, which you haven't provided. Since our mindreading skills are not the best, we have no way of know what you are doing wrong.

But you know that an answer of 666.6v is not correct (assuming that 'v' is "volts", in which case is should be 'V') because you are looking for an amplifier gain, which is dimensionless.