如题图14－13所示，曲率半径为R<sub>1<／sub>和R<sub>2<／sub>的两个平凸透镜对靠在一起，中间形成一个空气薄层，用

<img src='https://img2.soutiyun.com/ask/2020-11-15/974324820322645.png' />

A．5V B．6V C．7V D．8V

<img src='https://img2.soutiyun.com/ask/2020-11-19/974672657164018.png' />

电路如题图5-7所示，已知电源电压为正弦电压，电流I₁=I₂=10A，试<img src='https://img2.soutiyun.com/ask/2021-01-03/978529327380181.png' />和<img src='https://img2.soutiyun.com/ask/2021-01-03/978529340109909.png' />，设<img src='https://img2.soutiyun.com/ask/2021-01-03/978529340109909.png' />的初相角为零。 <img src='https://img2.soutiyun.com/ask/2021-01-03/978529357270891.png' />

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一质点P从0点出发以匀速率0.1 m·s-1作半径为1 m的圆周运动,如题图1.5所示.当它走完2/3四周时,它走过的路程是多少？这段时间内的平均速度如何？ <img src='https://img2.soutiyun.com/ask/2020-04-03/954761018699512.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-04-07/955116604116982.jpg' />

如题图9.26所示,一根半径为R,的长直圆柱形铜导线(μr=1),外包一层相对磁导率为p,的圆简状顺磁质,顺磁质的外半径为R,导线内有电流I从纸面向外的方向流动，且电流I均匀分布在导线的横截面上,求空间的磁感应强度B和磁场强度H. <img src='https://img2.soutiyun.com/ask/2020-04-07/9551176128393.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-10-09/971112325717225.jpg' />

电路如题图5-8所示，已知R₁=10Ω，C=10³μF，R₂=0.5Ω，ω=1000rad/s，<img src='https://img2.soutiyun.com/ask/2021-01-03/978529389968761.png' />求当电流有效值I最大时，电感L为何值？ <img src='https://img2.soutiyun.com/ask/2021-01-03/978529403802552.png' />

电路如题图E4-2所示，E=2V，R=10Ω，u_c(0^-)=0V，i_L(0^-)=0A，S在t=0时刻合上，求： <img src='https://img2.soutiyun.com/ask/2020-11-14/974195052088126.png' /> <img src='https://img2.soutiyun.com/ask/2020-11-14/974195076349514.png' />

在匀强电场E中,有一半径为R的闭合半球面,其底面与电场线垂直，如习题7-14图所示。试求:(1)分别通过闭合半球面底面和球面的电场强度通量;(2)半球面内的总电荷量。 <img src='https://img2.soutiyun.com/ask/2020-07-16/963760710032525.png' />

(1)滑轮在3s内的转数。 (2)当t=3s时重物B的速度和经过的路程。 (3)当1=0时滑轮边缘上点C的加速度。 <img src='https://img2.soutiyun.com/ask/2020-12-09/976392049413852.png' />

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<img src='https://img2.soutiyun.com/ask/2020-10-07/970927289819887.png' />

半径R=100mm的圆盘绕其圆心转动，图7-12a所示瞬时，点A的速度为v_a=200jmm/s，点B的切向加速度<img src='https://img2.soutiyun.com/ask/2021-03-01/983460973982692.png' />。求角速度ω和角加速度α，并进一步写出点C的加速度和矢量表达式。 <img src='https://img2.soutiyun.com/ask/2021-03-01/983460984520295.png' />

如题图14-3所示，在杨氏双缝干涉实验中，若<img src='https://img2.soutiyun.com/ask/2020-10-10/971196334319648.jpg' />=r₂-r₁=λ/3，求P点的强度I与干涉加强时最大强度I_max的比值。 <img src='https://img2.soutiyun.com/ask/2020-10-10/971195556849179.jpg' />

<img src='https://img2.soutiyun.com/ask/2020-04-07/955125893923024.jpg' />

(1)计算静态值I_B，I_c，U_cE; (2)画出微变等效电路，求两个输出端的电压放大倍数<img src='https://img2.soutiyun.com/ask/2020-11-15/974326186869807.png' /> (3)求该电路输入电阻ri和两个输出端的输出电阻r₀₁和r₀₂ (4)如果输入信号是正弦信号，试对比输入信号定性画出输出电压u₀₁及u₀₂波形; (5)找出电路的反馈元件，如果从集电极输出电压，属何种类型反馈？如果从发射极输出电压，属何种类型反馈？ <img src='https://img2.soutiyun.com/ask/2020-11-15/974326193406181.png' />

单相桥式整流电容滤波电路如题图E9-2所示，变压器:二次电压<img src='https://img2.soutiyun.com/ask/2020-11-14/97419657881545.png' />求 (1)负载电流I₀，每个二极管的平均电流ID，二极管承受的反向峰值电压U_DRM; (2)当DI管发生短路时的负载电流I₀，D4管的电流I_D4; (3)当DI管发生虚焊断路时的负载电流I₀，D4管的电流I_D4。 <img src='https://img2.soutiyun.com/ask/2020-11-14/974196590724131.png' />

<img src='https://img2.soutiyun.com/ask/2021-02-21/982799735258245.png' />