某计算机使用通信效率为80%,速度为12.5kb/s的异步通信传输文件，则传输125KB的文件需要（）秒。
- A.10
- B.80
- C.100
- D.102.4
正确答案及解析
正确答案
解析
文件大小为125KB=125*1024*8 bit，由于异步通信需要有起始符，校验位等，效率为80%的信道，实际速率为125000bps*0.8=100000bps.因此传输时间=125*1024*8/100000=102.4s
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