In a noninverting amplifier, the input signal is applied to the

In a noninverting amplifier, the input signal is applied to the

• A. Noninverting input; 1 + (Rf/Rin)
• B. Inverting input; -Rf/Rin
• C. Noninverting input; Rin/Rf
• D. Inverting input; 1

Answer: (A)

In a noninverting amplifier, the input signal goes to the noninverting (+) input. The feedback network connected between the output and the inverting (−) input, with a resistor to ground, sets the gain through negative feedback. The closed-loop gain for this configuration is 1 + (Rf/Rin). That’s why the correct statement is that the input is applied to the noninverting input and the gain is 1 + (Rf/Rin). The other options don’t fit because the input is not applied to the inverting input in this setup, and the gain formula shown there (such as -Rf/Rin or Rin/Rf) corresponds to other configurations or is simply the wrong expression for a noninverting amplifier.

In a noninverting amplifier, the input signal goes to the noninverting (+) input. The feedback network connected between the output and the inverting (−) input, with a resistor to ground, sets the gain through negative feedback. The closed-loop gain for this configuration is 1 + (Rf/Rin). That’s why the correct statement is that the input is applied to the noninverting input and the gain is 1 + (Rf/Rin).

The other options don’t fit because the input is not applied to the inverting input in this setup, and the gain formula shown there (such as -Rf/Rin or Rin/Rf) corresponds to other configurations or is simply the wrong expression for a noninverting amplifier.