The voltage gain of a non-inverting operational amplifier is:

1. In the non-inverting configuration the input signal goes to the non-inverting terminal. 2. The feedback network of $R_f$ and $R_1$ sets how much of the output returns to the inverting input. 3. The resulting closed-loop gain is $A=1+\dfrac{R_f}{R_1}$. 4. The leading 1 means the gain can never fall below unity, and the output stays in phase with the input. 5. Dropping that 1 gives the inverting amplifier's gain magnitude instead, which is a different circuit. _Source: NECTA ACSEE 2023 Physics 131/1, Question 9: Electronics (Semiconductors,Logic Gates & Op-Amps)_