题干

小凯和小明为了弄清一个未知电阻的阻值,小凯将未知电阻、电流表、电压表、滑动变阻器、开关和电源连接成了如图甲所示的电路,小凯正准备闭合开关时,旁边的小明急忙拦住他,说线接错了。

①小明发现只要改接一根导线就可以连接正确,请你检查一下电路,指出改接的是____导线。(选填:a、b、c、d、e、f、g)

②故障排除后,电阻两端的电压表示数如图乙所示,其读数为____V。

③小凯在实验中通过调节滑动变阻器滑片,测出通过电阻R的不同电流和对应的电压值,如下表所示;

根据表中数据在图丙中画出电阻R的I—U关系图像____

④由③中数据求出该电阻的阻值为____Ω。(保留一位小数)

上一题 下一题 0.0难度 选择题 更新时间:2018-11-29 08:36:57

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d,1.4V,,5.0

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任务型阅读

    Humans use electricity to light up the night sky. But did you know that nature itself can glow, too?

    ____. Some use their lights to communicate. Others shine to hunt, to mate or to protect themselves. The vampire squid, for example, gives out a cloud of light to scare enemies.

    ____.

    In 2013, the US company Gleaux said it had created the world's first light-producing plant, reported the Daily Mail.

    ____.

    “People have dreamed about this stuff for many years,” said Alexander Krichevsky, the company's founder.

    He and other researchers are working toward a future in which glowing plants replace lamps and glowing trees line highways.____, making them glow to let farmers know when they need water or are ready to be picked.

    While GleauX is working on glowing plants, the French company Glowee is trying to use glowing bacteria to light up shop windows and street signs. It is the same type of bacteria that causes certain sea animals to light up.

    ____.The company is now working on a light that shines brighter, lasts longer and comes in different colors.

    “Our goal is to change the way we produce and use light,” said Glowee founder Sandra Rey. “We want to offer a global solution that will reduce the 19 percent of electricity consumption used to produce light.”

A. People are also creating glowing bacterial art that you can hang in your home

B. Scientists have found many glowing creatures, most of which live in the ocean

C. Krichevsky also hopes the technology could be used in crops

D. Researchers around the world are looking into nature's lights for new ideas

E. It is a genetically-modified plant that glows like fireflies do

F. In 2016, Glowee created a bacteria-powered light that glows for three days

G. This technology could help us save much energy