The above circuit was used to determine the input/output characteristics of an operational amplifier. A voltage divider provides a variable DC input between 0 and 2 V. The DC output varies between 0 and 10 V. These voltages are measured by voltmeters labelled V_input and V_output respectively in the diagram.

The table below shows input and output voltage readings. These results were used to draw a graph using an Excel spreadsheet.

Vinput V Voutput V +2.0 +1.5 +1.0 +.5 0 -0.5 -1.0 -1.5 -2.0 -8.0 -8.0 -8.0 -4.0 0 +4.0 +8.0 +8.0 +8.0

With reference to the graph:
What range of the graph gives a linear response? (Answer: From an input of +1 V to -1V.)
What is the saturation value for the opamp in the above circuit? (Answer: +8V and -8V.)
What is the voltage gain within the linear range? (Answer: the gradient of the line is -8, so the gain is 8, inverting.)

From R Muncaster, "A-level physics", Stanley Thornes (Publishers) Ltd., 3^rd Edition 1990, p. 928.