题干

(2010·全国卷Ⅰ·16)关于静电场,下列结论普遍成立的是(   )

A:电场中任意两点之间的电势差只与这两点的场强有关

B:电场强度大的地方电势高,电场强度小的地方电势低

C:将正点电荷从场强为零的一点移动到场强为零的另一点,电场力做功为零

D:在正电荷或负电荷产生的静电场中,场强方向都指向电势降低最快的方向

上一题 下一题 0.0难度 选择题 更新时间:2019-01-09 09:39:25

答案(点此获取答案解析)

C

同类题3

根据短文理解,回答下列问题。

    The Internet is becoming more and more important in our life. How much do you know about it? What is the Internet? The Internet is a large, worldwide collection of computer networks. A network is a small group of computers put together. The Internet is many different networks from (A)                 the world. These networks are called the Internet. Once you have learned to use the Internet, you can have a lot of interest in the World Wide Web.

    What is the World Wide Web?

    The World Wide Web has been the most popular development of the Internet. The Web is like a big electronic book with millions of pages. These pages are called homepages. You can find information about almost anything in the world on these pages. For example, (B) you can use the Internet instead of a library to find information for your homework. You can also find information about your favourite sports or film stars, talk to your friends or even do some shopping on the Internet. Most pages have words, pictures and even sound or music.

    What is e-mail? (C)电子邮件是给别人发送信息的一种方法。 It's much quicker and cheaper than sending a letter. If you want to send e-mails, you must have an e-mail address. This address must have letters and dots(点 ) and an ‘@’( meaning ‘at'). This is what an address looks like: Emily @ star. net. Write a message, type in the person's e-mail address, and then send the message on the Internet. People don't need to use stamps, envelopes or go to the post office since the invention of the Internet. Quick. easy and interesting--that's the Internet!