Calculate the value of the feedback resistor if the voltage gain Av of 12 and an input resistor of 1.3kΩ was read from the non-inverting operational amplifier.

The voltage gain ($A_v$) for a non-inverting operational amplifier is given by the formula:

$$A_v = 1 + \frac{R_f}{R_1}$$

Given values:

• Voltage gain, $A_v = 12$
• Input resistor, $R_1 = 1.3 \, \text{k}\Omega = 1300 \, \Omega$

Subtract 1 from both sides:

$$12 - 1 = \frac{R_f}{1300 \, \Omega}$$ $$11 = \frac{R_f}{1300 \, \Omega}$$

Multiply both sides by $1300 \, \Omega$:

$$R_f = 11 \times 1300 \, \Omega$$

$$R_f = 14300 \, \Omega$$

Convert to kilohms:

$$R_f = 14.3 \, \text{k}\Omega$$

The value of the feedback resistor is $\text{14.3 k}\Omega$.