Topic: Analog Circuits
The circuit is with an ideal operational amplifier with ±10 V supply. The output voltage is:
- A. -200 mV
- B. -400 mV
- C. -600 mV
- D. -300 mV
Answer: B. -400 mV
Explanation: Applying virtual ground V_A = V_B = 0 V. Nodal analysis at the inverting node B: (V_B - 40 mV)/2 kΩ + (V_B - 20 mV)/1 kΩ + (V_B - V_out)/10 kΩ = 0. Substituting V_B = 0 V yields V_out = -20 mV * 10 - 20 mV * 10 = -400 mV.