【简答题】一台并励直流电动机的额定数据为: P N =17kW , U N =220V , I N =92A , R a =0.08Ω , R f =110Ω , n N =1500r/min ,试求:(20分) ( 1 )额定负载时的效率; ( 2 )额定运行时的电枢电动势 E a ; ( 3 )额定负载时的电磁转矩。
【单选题】Part II Listening Comprehension (25 minutes) Section A Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the ...
【单选题】Part II Listening Comprehension (25 minutes) Section A Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the ...
A.
The International Labour Organization's key objective.
B.
The basic social protection for the most vulnerable.