This circuit is used for testing and where we want to convert analogous quantity into corresponding voltage .In the bridge we replace one resistor with tranducer ,so as an illustration we increase or decrease resistance to vary the voltage levels .case 1 if all resistor are same voltage Vout =zero ,at the instance you will change resistance you will see variations in voltage .construction:contains one bridge ,two voltage followers and one difference amplifier.voltage followers are used to prevent loading of the bridge as they didnt allow large current to pass through them.
