一台三相4极的感应电动机，额定转速nN=1440r/min，转子电阻实际值R2=0.

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问题单项选择题

一台三相4极的感应电动机，额定转速n_N=1440r/min，转子电阻实际值R₂=0.16Ω。电机原来运行在额定状态。在负载转矩不变的情况，现将转速降为：1300r/min，则转子电路中应串入的电阻为( )Ω。

A．(A) 0.350

B．(B) 0.395

C．(C) 0.373

D．(D) 0.413

答案

参考答案：C

句型转换

句型转换.

1. If I were you, I would wear a shirt and tie to the meeting. (对画线部分提问)

would you wear to the meeting if you me?

2. Betty is very quiet and shy. She's always so nervous that she can't speak in public. (改为同义句)

Betty is very quiet and shy. She's always nervous ____ ___ speak in public.

3. My parents won't allow me to keep a pet dog at home. (改为同义句)

My parents won't let me ____ a pet dog at home.

4. He got up late so he couldn't catch the early bus. (改为简单句)

He got up ________ _________ the early bus.

5. If it is fine, we'll go for a picnic. (改为虚拟语气的同义句)

If it ________ fine, we go for a picnic.

填空题

发生器液面高度（）溢流管一筒上端高度，（）振荡器物料筒150mm以上。