*Question G7B03:
Which of the following describes the function of a two-input AND gate?*  

*Correct Answer is  B: Output is high only when both inputs are high*  

### AI Response: (may contain errors)  

An AND gate is a basic digital logic gate that implements logical conjunction. Here's how it works:

1. **Correct Answer (B): Output is high only when both inputs are high**  
   - An AND gate outputs a high signal (1) only when all of its inputs are high (1). For a two-input AND gate, this means both inputs must be high for the output to be high.
   - Truth Table for a two-input AND gate:
     - Input A = 0, Input B = 0, Output = 0
     - Input A = 0, Input B = 1, Output = 0
     - Input A = 1, Input B = 0, Output = 0
     - Input A = 1, Input B = 1, Output = 1

2. **Why the other choices are incorrect:**
   - **Choice A: Output is high when either or both inputs are low**  
     - This describes a NOR gate, not an AND gate. An AND gate requires both inputs to be high for the output to be high.
   - **Choice C: Output is low when either or both inputs are high**  
     - This describes a NAND gate, which is the opposite of an AND gate. A NAND gate outputs low only when both inputs are high.
   - **Choice D: Output is low only when both inputs are high**  
     - This is also a description of a NAND gate. An AND gate outputs high when both inputs are high, not low.

3. **Useful Rule of Thumb:**
   - For an AND gate, think of it as a "both must be true" condition. Both inputs need to be true (high) for the output to be true (high).