![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
【听力A】Fill out the space after the record.(听录音完成填空;注意填写答案时,答案前后一定不要留空格或符号,系统自动阅卷,可能会检测有误。) When a drain-source voltage increases further, however, something rather surprising happens: the 1 current levels off and remains virtually constant with increasing V DS . The reason is a voltage drop (IR drop) along the 2 N-channel material. If the gate is at ground 3 (relative to source) and the 4 region near the top of the bar is at a voltage V DS , the gate is 5 relative to the channel by about this voltage. Thus, the gate-channel diode 6 is reverse biased by the amount V DS , and a large depletion zone is 7 that tends to pinch off the channel. However, the current does not stop because the IR 8 would then vanish and the channel would open again; instead, a 9 channel forms that becomes longer with increased V DS so that the current 10 remains practically constant.