问题 选择题

关于电流、电压和电阻的关系,下列说法中正确的是

A.导体的电阻与电压成正比,与电流成反比

B.导体的电阻越大,这段导体两端的电压就越高

C.导体两端的电压越高,通过这段导体的电流就越大

D.通过导体的电流越大这段导体的电阻就越小

答案

答案:C

题目分析:电阻一定时,通过它的电流跟它两端的电压成正比;电压一定时,电流跟电阻成反比。电阻是导体本身的一种性质,跟电压和电流无关。

A.导体的电阻与电压成正比,与电流成反比 不合题意;

B.导体的电阻越大,这段导体两端的电压就越高 不合题意;

C.导体两端的电压越高,通过这段导体的电流就越大 符合题意;

D.通过导体的电流越大这段导体的电阻就越小 不合题意;

故选C。

点评:了解电流、电压和电阻的关系是解决此题的关键。电阻是导体本身的一种性质,跟电压和电流无关。

单项选择题 A1/A2型题
阅读理解

B

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Wise use of free time does not mean getting an advanced degree, although the mental encouragement gained through education is unbeatable in keeping your mind active.Learning new things nearly always adds a spark to your daily life, especially if it is a favorite topic, such as sport, fashion, or art.Also, look through your bookstore or library to find books on your interests.Try to replace a half hour TV watching with reading.

Itis reported that in the United States recently, many individuals have as few as two good friends.Long work hours and car commute act to separate people from each other.This separation is deadly.Find ways to meet people at the end of the day and on weekends.Often this can be best done by combining activities, such as by joining a walking group to get both exercise and companionship.Taking a class will lift your spirits and allow you to meet others with similar interests.Hobbies are great for reducing stress and provide another opportunity for social interaction.

Using your free time to aid your health may include these elements and many more, such as going to concerts and spending time with family.Overall, the key is to spend less free time being passive.The best ways to use free time are to be mentally and physically active, spend some time outdoors, and interact with other people on a regular basis.

60.What can we learn from the passage?

A.Watching television may cause women to feel depressed.

B.Finding interests and hobbies in common means taking a class.

C.Going to concerts is the best way to make you mentally active.

D.Getting an advanced degree in education always lights up your life.

61.What does the underlined word "commute" in Paragraph 3 probably mean?

A.The arrangement to work every day.   B.The journey to work every day

C.The communication between people.   D.The separation between people

62.Which would be the best title for the passage?

A.Live a Happy and Healthy Life    B.Relax Yourself in Various Ways

C.Spend Your Free Time Wisely       D.Interact With Others Outdoors