功A=∑p△V或<img src='https://img2.soutiyun.com/ask/2020-02-18/950872487853621.png' />的适用范围是______。

=（）,V为椭球体<img src="http://p.ananas.chaoxing.com/star3/origin/e981894cbdecffcd2cb4a2d6522f36dc.png"/> <img src="http://p.ananas.chaoxing.com/star3/origin/fab2eb45ac2076ba37a334f99db6a6b6.png"/>

所围成的区域的体积V=（）。<img src="http://p.ananas.chaoxing.com/star3/origin/c5e11583f888152875083a4d4f41b52a.png"/>

应用在空调机上的整流电路，输出电压为如0 V， 测得的电流为0. 5 A， 则负载的等效电阻为（）<img src='' jquery111005450221144239208=' /><img src='https://img2.soutiyun.com/ask/uploadfile/5265001-5268000/8525602aed298ae87ad044b1dbcb7d19.gif' />

图示结构受一水平力P的作用，铰支座A的反力RA的作用线应该是()<img src='https://img2.soutiyun.com/shangxueba/ask/1989001-1992000/1990838/ct_jgzjgysm_jgzjgyschoose_00169(20093).jpg' />

孔隙率P′计算公式<img src='https://img2.soutiyun.com/ask/uploadfile/10173001-10176000/c8b1d26d4107a58c193b1d1cb9356dfe.png' />式中ρ0′为()

已知事件A、B满足<img src='https://img2.soutiyun.com/ask/2019-12-25/946136490188197.png' />，则P(A-B)=( )．

三相四线制对称电源<img src='https://img2.soutiyun.com/ask/6489001-6492000/b6353df5b02f35836ce61033b0de5fcd.jpg' />，接入一个三角形连接的对称三相负载后，<img src='https://img2.soutiyun.com/ask/6489001-6492000/2f7cb60cbe77c048a52a64e8c331e4f0.jpg' />，该负载消耗的功率P=( )。

已知P(A)=P(B)=<img src='https://img2.soutiyun.com/latex/latex.action' />，则下列结论肯定正确的是( )

设随机事件A在第i次独立试验中发生的概率为p_i，i=1，2，...，n。m表示事件A在n次试验中发生的次数，则对于任意正数ε{ε＞0}，证明<img src='https://img2.soutiyun.com/ask/2020-12-28/978025287070883.jpg' />

老年男性，咳嗽、咳痰20余年，活动后气促10年。体检：桶状胸，两肺可闻及干、湿啰音，P亢进。心电图V～V呈QS波，RV+SV=1.5mV。胸片见图，因诊断为()<img src='https://img2.soutiyun.com/shangxueba/ask/17658001-17661000/17660784/2014060609092349886.jpg' />

设P(A)=a，P(B)=b，P(A+B)=c，则<img src='https://img2.soutiyun.com/latex/latex.action' />为( )

设A、B为任意两事件，且<img src='https://img2.soutiyun.com/ask/2020-03-06/952348543191874.png' />，P(B)＞0，则下列选项必然成立的是( )

右图中,ABCD为正方形,r为影响车辆行驶速度的阻尼系数。若时间=r·s/v,其中v为车辆行驶速度,s为车辆行驶距离,从A到C花费时间最短的线路是()。<img src='https://img2.soutiyun.com/ask/2019-03-04/920565164095157.png' />

图示铰接排架，如略去杆件的轴向变形，当A点发生单位水平位移时，则P的大小为（）。<img src='https://img2.soutiyun.com/ask/uploadfile/5763001-5766000/6c17ce11b0a938a1ee43ae1397fba62c.jpg' /><img src='https://img2.soutiyun.com/ask/uploadfile/5763001-5766000/d7bb6cad4a026f3a7b8bb625cdb0488a.jpg' />

如图，当V_A=V_B=0时，V_Z=（）V。<img src='https://img2.soutiyun.com/shangxueba/ask/18495001-18498000/18497830/2015062514434232068.jpg' />

天线P、Q为两个以同相位、同频率、同振幅振动的相干波源，它们在同一介质中，设频率为v,波长为入,P、Q间距离为气<img src='https://img2.soutiyun.com/ask/2020-04-09/955270692282608.jpg' />,R为PQ延长线上离Q很远的一点:两波在该点的振幅可视为相等试求:

右图中如A点和C点电位分别为+24V和0V，则B点电位为_______。<img src='https://img2.soutiyun.com//1/2021-06-18/992897200285074.jpg' />

压差传感器结构如图4-30a所示，传感器接入二极管双T型电路，电路原理示意图如图4-30b所示。已知电源电压U_E=10V,频率<img src='https://img2.soutiyun.com/ask/2020-07-30/96495025769614.png' />,压差电容<img src='https://img2.soutiyun.com/ask/2020-07-30/964950278067305.png' /><img src='https://img2.soutiyun.com/ask/2020-07-30/964950289233943.png' />。试分析，当压力传感器有压差<img src='https://img2.soutiyun.com/ask/2020-07-30/964950298895496.png' />使电容变化<img src='https://img2.soutiyun.com/ask/2020-07-30/964950306739945.png' />时，一个周期内负载电阻上产生的输出电压U_RL平均值的大小与方向。

一台4极中型异步电动机，P_N=200kW，U_N=380V,定子0联接，定子额定电流I_N=385A,频率50Hz,定子铜耗<img src='https://img2.soutiyun.com/ask/2021-01-03/978560273352189.png' />=5.12kW.转子铜耗<img src='https://img2.soutiyun.com/ask/2021-01-03/978560286697952.png' />=2.85kW,铁耗<img src='https://img2.soutiyun.com/ask/2021-01-03/978560298531629.png' />=3.8kW，机械损耗<img src='https://img2.soutiyun.com/ask/2021-01-03/97856031340548.png' />=0.98kW，附加损耗<img src='https://img2.soutiyun.com/ask/2021-01-03/978560322980028.png' />=3kW，<img src='https://img2.soutiyun.com/ask/2021-01-03/978560339469971.png' />.正常运行时<img src='https://img2.soutiyun.com/ask/2021-01-03/978560353474772.png' />，起动时<img src='https://img2.soutiyun.com/ask/2021-01-03/978560375203015.png' />，由于磁路饱和与趋肤效应的影响，<img src='https://img2.soutiyun.com/ask/2021-01-03/978560441999835.png' /><img src='https://img2.soutiyun.com/ask/2021-01-03/97856039470213.png' />.试求:

如图，当V_A=V_B=3V时，则V_Z=（）。<img src='https://img2.soutiyun.com/shangxueba/ask/18498001-18501000/18498701/201506251432481886.jpg' />

水管A、B两点高差h₁＝0.20m，U形压差计中水银液面高差h₂＝0.10m，则p_A-p_B＝（）。<img src='https://img2.soutiyun.com/shangxueba/ask/19011001-19014000/19011061/2016071909073918369.jpg' />

某种理想气体在其状态变化过程中服从pvⁿ=常数的规律，其中n是定值，p是压力; v是比体积。试据<img src='https://img2.soutiyun.com/ask/2020-09-30/97030685032371.png' />导出气体在该过程中做功为

在图9-33所示的快慢速换接回路中，已知液压缸大小腔面积为A₁和A₂,，快进和工进时负载力为F₁和F₂(F₁＜F₂)，相应的活塞移动速度为v₁和V₂。若液流通过节流阀和卸荷阀时的压力损失为<img src='https://img2.soutiyun.com/ask/2021-01-04/978617220440546.png' />和<img src='https://img2.soutiyun.com/ask/2021-01-04/97861723204821.png' />，其他地方的阻力可忽略不计，试求:

题图所示电路中，U=220V，I=2A，元件A消耗的功率为()<img src='https://img2.soutiyun.com//1/2021-05-26/990874616096711.png' />