Topic: Analog Circuits
In the op-amp circuit given in figure, the load current $i_L$ is
- A. $-\frac{V_s}{R_2}$
- B. $\frac{V_s}{R_2}$
- C. $-\frac{V_s}{R_L}$
- D. $-\frac{V_s}{R_1}$
Answer: A. $-\frac{V_s}{R_2}$
Explanation: $\frac{V_s - V}{R_1} = \frac{V - V_0}{R_1} \Rightarrow V_s - 2V = -V_0$ ...(ii)\n$\frac{V}{R_2} + \frac{V}{R_L} = \frac{V_0 - V}{R_2} \Rightarrow 2\frac{V}{R_2} + \frac{V}{R_L} = \frac{V_0}{R_2}$ ...(i)\nPutting $V_0$ from equation (i) in equation (ii) we get\n$\frac{-V_s + 2V}{R_2} = -(\frac{2V}{R_2} + \frac{V}{R_L})$\n$I_L = \frac{V}{R_L} = -\frac{V_s}{R_2}$