Question

Given v1 = 2 vpp, v2 = 3 vpp, r1 = r2 = 3 kω, rf = r3 and vout = 7 vpp, find rf .

Answer 1

To find the value of rf in the circuit, we can use the voltage divider equation and the given values of v2, vout, and r2. Substituting these values into the equation and solving for rf gives us a value of -5.25 kΩ.

Step-by-step explanation:

To find the value of rf, we can use the voltage divider equation. The voltage divider equation states that the output voltage is equal to the input voltage multiplied by the ratio of the resistances. Since rf = r3, we can write the equation as follows:

vout = v2 * (rf / (rf + r2))

Using the given values, we can substitute in v2 = 3 vpp, vout = 7 vpp, and r2 = 3 kΩ. Solving for rf:

7 = 3 * (rf / (rf + 3))

7 = 3rf / (rf + 3)

7rf + 21 = 3rf

4rf = -21

rf = -21 / 4

Therefore, the value of rf is -21 / 4 or -5.25 kΩ.