Topic: Electronics Engineering
In the circuit shown in the below figure, the value of output $V_{0}$ is
- A. +6 V
- B. -9 V
- C. -6 V
- D. +9 V
Answer: B. -9 V
Explanation: $V_{0}=-R_{f}(\frac{V_{a}}{R_{a}}+\frac{V_{b}}{R_{b}}+\frac{V_{c}}{R_{c}}) = -120(\frac{1}{40}+\frac{2}{80}+\frac{3}{120}) = -9V$