*Question E6A10:
In Figure E6-1, which is the schematic symbol for an N-channel dual-gate MOSFET?*  

*Correct Answer is  B: 4*  

### AI Response: (may contain errors)  

In Figure E6-1, you are asked to identify the schematic symbol for an N-channel dual-gate MOSFET. Let's break down the options:

1. **Correct Answer: 4**  
   - The symbol for an N-channel dual-gate MOSFET includes:
     - A source (S), drain (D), and two gates (G1 and G2).
     - An arrow on the source pointing inward, indicating an N-channel device.
     - Two gate lines, which distinguish it as a dual-gate MOSFET.
   - This configuration is unique to dual-gate MOSFETs, which are used for applications like RF amplifiers due to their ability to control gain and bandwidth.

2. **Why the Other Choices are Incorrect:**
   - **Choice A: 2**  
     - This symbol might represent a different type of MOSFET or a single-gate MOSFET, lacking the second gate line.
   - **Choice C: 5**  
     - This could be a symbol for a P-channel MOSFET, which would have the arrow pointing outward from the source.
   - **Choice D: 6**  
     - This might represent a different semiconductor device, such as a JFET or a single-gate MOSFET, without the dual-gate feature.

**Key Points to Remember:**
- **N-channel MOSFETs** have the arrow pointing inward on the source.
- **Dual-gate MOSFETs** have two gate lines, which is a distinguishing feature.
- **P-channel MOSFETs** have the arrow pointing outward.

Understanding these symbols is crucial for identifying components in circuit diagrams and for practical applications in electronics.