A non-inverting summing amplifier cannot scale or weight input signals. Which of the following statements is false?

A non-inverting summing amplifier cannot scale or weight input signals. Which of the following statements is false?

• A. They can scale or weight input signals.
• B. They cannot scale or weight input signals.
• C. They preserve the input polarity.
• D. They provide high input impedance.

Answer: (B)

The main idea here is that a non-inverting summing amplifier can combine and weight multiple input signals before applying gain. This is done by using a resistor network at the non-inverting input that creates a weighted average of the inputs. The op-amp’s feedback then provides a non-inverting gain, so the final output is a scaled version of that weighted sum. Because the input sees a high-impedance node, the sources aren’t loaded, and each input’s influence can be adjusted by choosing appropriate resistor values. The non-inverting configuration also preserves the polarity of the inputs since there is no phase reversal in this path. So the statement claiming it cannot scale or weight input signals is false, because the resistor network at the non-inverting input enables weighting, and the overall gain scales that weighted sum. The other properties—preserving input polarity and providing high input impedance—are consistent with a non-inverting arrangement.

The main idea here is that a non-inverting summing amplifier can combine and weight multiple input signals before applying gain. This is done by using a resistor network at the non-inverting input that creates a weighted average of the inputs. The op-amp’s feedback then provides a non-inverting gain, so the final output is a scaled version of that weighted sum. Because the input sees a high-impedance node, the sources aren’t loaded, and each input’s influence can be adjusted by choosing appropriate resistor values. The non-inverting configuration also preserves the polarity of the inputs since there is no phase reversal in this path.

So the statement claiming it cannot scale or weight input signals is false, because the resistor network at the non-inverting input enables weighting, and the overall gain scales that weighted sum. The other properties—preserving input polarity and providing high input impedance—are consistent with a non-inverting arrangement.