(10分)如图所示,M为一线圈电阻RM=0.4Ω的电动机,R=24Ω,电源电动势

题型:计算题

问题:

(10分)如图所示,M为一线圈电阻RM=0.4Ω的电动机,R=24Ω,电源电动势E=40V.当S断开时,电流表的示数I1=1.6A,当开关S闭合时,电流表的示数为I2=4.0A。求

(1)电源内阻r

(2)开关S闭合时,通过电动机的电流及电动机消耗功率

考点:焦耳定律,电热电功
题型:计算题

阅读下面的材料,然后根据材料内容回答所提问题。

     Once upon a time, there was an island. All the feelings lived there such as Happiness, Sadness, and Love.

One day the feelings heard that the island would sink (下沉). They all repaired their boats and left except Love.

Love wanted to stay until the last possible moment. Just as the island began to sink, Love decided to ask for

help.

     Miserliness (吝啬) was passing by Love in a big boat. Love said:"Miserliness, can you take me with you?"

Miserliness answered:"No, I can't. There are a lot of silver (银子) in my boat. There is no place for you here."

     Love decided to ask Vanity (虚荣) who was also passing by in a beautiful boat."Vanity, please help me!"

"I can't help you, Love. You are all wet. You'll make my boat dirty," Vanity said.

     Sadness was close by, so Love asked for help, "Sadness, let me go with you." "Oh…Love, I am so sad

that I need to be alone by myself!"

     Happiness passed by Love too, but she was so happy that she did not even hear Love call her.

     Suddenly, there was a voice, "Love, I will take you." It was an old woman. Love felt so lucky that he even

forgot to ask for her name. When they got to dry land, the old woman went away. Love asked Knowledge,

another old woman, "Who helped me?"

     "It was Time", Knowledge answered. "Time?" asked Love. "But why did Time help me?"

     Knowledge smiled with deep wisdom (智慧) and answered, "Because only Time can understand how great

Love is."

1. Where did the feelings live?

    __________________________________________________________

2. What was there in Miserliness's big boat? 

    __________________________________________________________

3. How many feelings did Love ask for help? 

    __________________________________________________________

4. All the feelings refused to take Love with them, didn't they?

    __________________________________________________________

5. Why did Time help Love? 

    __________________________________________________________

题型:计算题

对心律失常患者进行病史采集时,下列哪项不能提供对诊断有用的线索().

A.心律失常的存在及其类型

B.心律失常的诱发因素,如烟、酒、咖啡、运动及精神刺激等

C.心律失常发作的频繁程度、起止方式

D.心律失常是触发机制还是自律性增高

E.心律失常对药物和非药物方法(如体位、呼吸、活动等)的反应

题型:计算题

打算以灵活就业人员身份参保,不知能否参加哪些险种?

题型:计算题

利润的第三源泉,即在降低生产成本、降低销售成本的同时,也要着眼于降低()。

A.物流成本

B.库存成本

C.人工成本

D.运输成本

题型:计算题

若地气障碍电阻小于电缆环阻的一半,即可确定为()障碍。

A.局内

B.线路

C.电缆

D.分线设备

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