试题与答案

开关断开、闭合时电路的识别: (1)如图1所示电路中,要使灯L1和L2连接成并联

题型:探究题

题目:

开关断开、闭合时电路的识别:

(1)如图1所示电路中,要使灯L1和L2连接成并联电路,应闭合开关_________;要使两灯连接成串联电路,应闭合开关_________,同时断开开关_________.如果同时闭合开关S1和S3则会出现_________

(2)如图2所示电路中,当只闭合开关S1时,_________亮;当只闭合开关S2时,灯_________亮;当开关S1、S2都闭合时,灯_________亮,此时是_________联电路;当开关S1、S2都断开时,灯_________亮,此时是_________联电路.

(3)如图3所示电路中,当只闭合开关S3时,灯_________亮;当开关S1、S2、S3都闭合时,灯_________亮,它们是_________联的.若想让L1和L3发光,L2不发光则应闭合开关_________,断开开关_________.

答案:

(1)S2和S3,S1,S2和S3,短路;

(2)L1,L3,L1、L2和L3,并,L1、L2和L3,串;

(3)L3,L1、L2和L3,并,S2和S3,S1

试题推荐
题型:问答题

American mythology loves nothing more than the reluctant hero: the man -- it is usually a man -- whose natural talents have destined him for more than obliging obscurity. George Washington, we are told, was a leader who would have preferred to have been a farmer. Thomas Jefferson, a writer. Martin Luther King, Jr., a preacher. These men were roused from lives of perfunctory achievement, our legends have it, not because they chose their own exceptionalism, but because we, the people, chose it for them. We -- seeing greatness in them that they were too humble to observe themselves -- conferred on them uncommon paths. Historical circumstance became its own call of duty, and the logic of democracy proved itself through the answer.Neil Armp was a hero of this stripe: constitutionally humble, circumstantially noble. Nearly every obituary written for him has made a point of emphasizing his sense of privacy, his sense of humility, his sense of the ironic ordinary. And yet every aspect of Armp’s life made clear: On that day in 1969, he acted on our behalf, out of a sense of mission that was communal rather than personal. The reluctant hero is also the self-sacrificing hero.

查看答案
题型:单项选择题

通过处理由光传递的信息,人们可以看到物体之间的空间联系。试图建造可以通过相同处理程序来察觉空间联系的计算机的科学家们至今已经设计并建造了固定的机器。但是,只有在这些科学家们生产出可以在其所处环境中移动的机器以后,他们才会实现其目标。下列哪项如果为真,最能支持上述结论______

A.人们往往可以轻易发现物体之间的空间联系,即使这些物体处于运动状态
B.虽然人们可以通过他们的听觉来识别空间联系,但是视觉通常是空间联系的最重要的方法
C.人们依靠有序运动得出的视觉暗示来发现空间联系
D.发现物体之间的空间联系需要对光传递的信息进行推理

查看答案
微信公众账号搜索答案