问题
名词解释
光纤的时延
答案
参考答案：
设一个单一的载频f0，携带一个调制信号，当光波频率很高，相对调制带宽很窄时，它在传输过程中的速度可用群速vg表示，则它传输每一单位长度时，所需要的时间T就称作每单位长度的时延。T=1/vg。
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光纤的时延
参考答案：
设一个单一的载频f0，携带一个调制信号，当光波频率很高，相对调制带宽很窄时，它在传输过程中的速度可用群速vg表示，则它传输每一单位长度时，所需要的时间T就称作每单位长度的时延。T=1/vg。
| 在B栏中找出A栏的正确答语。 | |
| A ( )1. What's that? ( )2. Who's that woman? ( )3. How are you? ( )4. How old are you? ( )5. Where are you from? ( )6. How many monkeys can you see? ( )7. Can I have some ice-cream? ( )8. How many pencils do you have? ( )9. What's your mother? ( )10. How do you do? ( )11. Can I use your pen? ( )12. Do you like bananas? ( )13. Who's that woman? ( )14. How many cats can you see? ( )15. Where is the ball? | B a. I have thirteen pencils. b. That's a pen. c. I'm from China. d. How do you do ? e. She is a teacher. f. I'm fine. g. She is my mother. h. I'm eleven. i. I can see twenty-two monkeys. J. Sure. k. Yes, I do. l. She's my mother. m. I can see 11. n. It's under the chair. o. Sure. |
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