题目内容
在正弦交流电路中,电压、电流的相位差取决于电路的阻抗角。
查看答案
搜索结果不匹配？点我反馈
更多问题
交流电路的阻抗角由电路参数决定,与交流电的频率无关。
Directions: In this section, you'll hear some long conversations. At the end of each conversation, some questions will be asked. Both the conversation and the questions will be spoken only once. After each question, choose the best answer from the four choices marked A, B, C, and D.Questions 1 to 4 are based on the conversation you have just heard.1.A . In 2000.B . In 2012.C . In 1996.D . In 2004.2.A . England.B . Greece.C . Australia.D . China.3.A . Listening and speaking.B . Listening and writing.C . Speaking and writing.D . Listening, speaking and writing.4.A . The man and the woman are friends.B . The man is not interested in any Olympic Games work.C . Both the man and the woman have worked as a volunteer for the Olympics.D . The woman didn't know much about the Olympics before.Questions 5 to 8 are based on the conversation you have just heard.5.A . Earthquake.B . Flood.C . Drought.D . Wildfire.6.A . British.B . Australian.C . Japanese.D . American.7.A . Shelter and cars.B . Food and shelter.C . Medicine and education.D . Money and medicine.8.A . Have lunch together.B . Make friends with each other.C . Go to the Red Cross.D . Buy a car.Questions 9 to 12 are based on the conversation you have just heard.9.A . The teacher asks him to be.B . He goes there to do a research.C . He goes there to give other people classes.D . He has no classes these days.10.A . By bus.B . By air.C . By car.D . By sea.11.A . In a pizza shop.B . In a car shop.C . At the Red Cross.D . In the disaster area.12.A . The disaster area.B . A car shop.C . The airport.D . The Red Cross.
如果信号分析设备的通频带比磁带记录下的信号频带窄，将磁带记录仪的重放速度（ ），则也可以满足分析要求。
瞬变信号x(t)，其频谱X(f)，则|X(f)|^2表示（ ）。
微信支付 
支付宝支付