问题 多选题

如图所示的图中,哪些图中a、b两点的电势相等,a、b两点场强度矢量也相等?(  )

A.

平行板电容器内a,b两点

B.

处于静电平衡状态下的金属内部a,b两点

C.

点电荷为球心的同一球面上的a,b两点

D.

关于两等量异种电荷连线对称的中垂线上的a,b两点

答案

A、a、b处于匀强电场中,场强相同,电势不同,a点电势高于b点电势.故A错误.

    B、处于静电平衡状态下的金属内部a,b两点,电场强度均为零,整个导体是等势体,电势相等.故B正确.

    C、a、b处于同一等势面上,电势相等,而电场强度方向不同.故C错误.

    D、a、b在等量异种电荷连线的垂直平分线上,电势相等,根据电场的对称性,a、b两点场强相同.故D正确.

故选BD.

阅读理解

Everyone experiences stress at work, but how we cope with it varies. Feeling that you’ve been unfairly treated can be particularly stressful. Researchers believe that failure to express feelings about unfair treatment at work could have serious consequences on your health, especially men, who bottle up their anger at being unfairly treated at work, are up to 5 times more likely to suffer a heart attack, or even die from one, than those who let their frustration (沮丧) show, a Swedish study has found.

The study by the Stress Research Institute of Stockholm University followed 2,755 employed men who had not suffered any heart attacks. At the end of the study, 47 participants had either suffered an attack, or died from heart disease, and many of those had been found to be covertly coping with unfair treatment at work.

“After adjustment for age, socioeconomic factors, risk behaviors, job strain and biological risk factors at baseline, there was a close-response relationship between covert coping and the risk of incident death,” the study’s authors wrote.

Covert coping was listed as “letting thing pass without saying anything” and “going away” despite feelings of being hard done by colleagues or bosses. Men who often used these coping techniques had a two to five times higher risk of developing heart disease than those who were more confrontational (对抗性的) at work, the study showed.

The researchers said they could not answer the question of what might be a particularly healthy coping strategy at work, but listed open coping behavior when experiencing unfair treatment or facing a conflict as “protesting directly,” “talking to the person right away,” “yelling at the person right away” or “speaking to the person later when things have calmed down.” The study was published in the Journal of Epidemiology and Community Health.

小题1:The study mainly shows that        .

A.women are less likely to suffer a heart attack than men

B.most people die of heart disease caused by stress

C.covert coping may result in certain heart trouble

D.employers should treat their workers equally小题2:Which of the following contributes to the accuracy of the study?

A.The participants were all employed men.

B.The participants tend to bottle up their temper.

C.The participants should not have risk behaviors.

D.The participants had not a history of heart attacks.小题3: According to the text, if treated unfairly a confrontational person will        .

A.just let it be

B.fight back immediately

C.go away silently

D.work even harder小题4:The last paragraph is intended to tell readers    .

A.that the study is official

B.what the healthiest coping strategy is

C.what the helpful ways of handling unfair treatment are

D.that confrontation is always beneficial to people’s heart health

单项选择题