Final answer:
The use of a 50 k potentiometer with an ideal op-amp as a variable noninverting amplifier cannot be confirmed without the diagram P9.47, but it is a common method to adjust gain in amplifiers. The precision is impacted by the potentiometer and op-amp specifications.
Step-by-step explanation:
The question pertains to the use of a potentiometer in conjunction with an ideal operational amplifier (op-amp) to create a variable noninverting amplifier. Based on the information provided, without figure P9.47, it is insufficient to definitively determine the accuracy of the statement that the potentiometer in combination with an ideal op-amp can be used as a variable noninverting amplifier. However, potentiometers are commonly used as variable resistors to adjust the gain in amplifier circuits, including noninverting configurations. In such a setup, the potentiometer can adjust the ratio of the feedback resistance to the input resistance, thereby changing the gain.
As a null measurement device, the potentiometer is used to measure potentials with great accuracy by balancing a circuit so that no current flows through the measuring device. This technique is different from its use in an amplifier circuit. In a noninverting amplifier configuration, accuracy is predominantly determined by the op-amp's properties and the precision of the resistors, including the potentiometer.