皮皮学，免费搜题
登录
搜题
【单选题】
如图所示电路中RL串联电路为日光灯的电路模型。将此电路接在50Hz的正弦交流电源上,测得端电压为220V,电流为0.4A,功率为40W。如果要求将功率因数提高到0.95,应给日光灯并联的电容C的值为( )μF。A.
3.29
B.
4.29
C.
5.29
D.
1.29
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】Part Ⅱ Reading Comprehension (Skimming and Scanning) Directions: In this part you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, cho...
A.
Because old people tend to sleep more than average.
B.
Because old people's health usually fails during that time.
C.
Because the life after retirement could be very long or very short.
D.
Because some old People cannot endure major surgeries.
【单选题】How did everyone teel when James left?
A.
They felt happy.
B.
They felt sorry.
C.
They felt excited.
【单选题】_____ shouldn’t have part-time jobs because they are too young.
A.
Thirteen years old
B.
Thirteen-year-old
C.
Thirteen-year-olds
D.
Thirteen year olds
【简答题】How did James Cook visit New Zealand?
【单选题】Part Ⅱ Reading Comprehension (Skimming and Scanning) Directions: In this part you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1～7 , ch...
A.
the causes of snoring problems
B.
the treatments of snoring problems
C.
the risks of snoring problems
D.
the hazards and the treatments of snoring problems
【简答题】In this part of the test you are asked to give a short talk o a business topic. You have to choose one of the topics from the two below and then talk for about one minute, you have one minute to prepa...
相关题目：