# Step-by-Step Solution and Logic Let's analyze logic circuit step by step. We'll track each input, gate, and output to understand when the LED turns ON. --- ## **1. Identify the Inputs and Their States** - **Switch A** = (connected to ground, **logic **) - **Switch B** = 1 (connected to +5V, **logic 1**) - **Switch C** = (connected to ground, **logic **) --- ## **2. Gate-by-Gate Analysis** ### **A. Inverter U1 (NOT Gate)** - **Input:** A = - **Output:** U1 = **NOT() = 1** ### **B. Inverter U2 (NOT Gate)** - **Input:** C = - **Output:** U2 = **NOT() = 1** ### **C. AND Gate U3** - **Inputs:** - Output of U1 (A') = 1 - B = 1 - **Output:** U3 = **A' AND B = 1 AND 1 = 1** ### **D. AND Gate U4** - **Inputs:** - Output of U3 = 1 - Output of U2 (C') = 1 - **Output:** U4 = **U3 AND C' = 1 AND 1 = 1** --- ## **3. LED Status** - **LED1** is connected to the output of U4. - Since U4 outputs **1 (HIGH, 3.3V)**, **LED1 turns ON**. --- ## **4. Logic Explanation** - The circuit logic can be summarized as: - LED1 = (NOT A AND B) AND (NOT C) - With A = , B = 1, C = : - NOT A = 1, NOT C = 1, so LED1 = (1 AND 1) AND 1 = 1 --- ## **5. Final Answer** ### **Final State** - **LED1 is ON.** --- ## **Summary Table** | Switch | Value | After NOT | Used in AND gates | Final Output | |--------|-------|-----------|-------------------|--------------| | A | | 1 | U3 | 1 | | B | 1 | - | U3 | 1 | | C | | 1 | U4 | 1 | --- ### **Conclusion** - **Logic Statement:** LED1 = (NOT A AND B) AND (NOT C) - **With switches A=, B=1, C=, the LED1 is ON.** --- **If you want to see the output for other switch combinations, let me know!**