题干

如图是安装了漏电保护器的家庭电路.家庭电路中火线与零线间、火线与大地之间有____ V电压.通常情况下,通过人体的电流超过20mA时,人会感到剧痛,呼吸困难,甚至会有生命危险.当人体直接或间接接触____ 时,有触电危险.此时,火线、人体、大地将构成回路,所产生的电流将不通过零线,此时通过如图线路中A、B两点的电流不等.当漏电保护器检测到通过图中A、B两处的电流不相等(即发生漏电)时,会迅速切断电路,从而起到保护作用.在特别潮湿的地方,因人体表皮电阻____ ,触电死亡的危险____ .假如有人在如图所示的电路C点处不慎触电时,漏电保护器____ (选填“会”或“不会”)切断路. 假如某人不慎触电时,且没有发生生命危险,则他的身体电阻至少为____ Ω.

上一题 下一题 0.0难度 选择题 更新时间:2015-08-24 03:03:13

答案(点此获取答案解析)

220,火线,减小,增加,会,11000

同类题4

阅读下面短文,从短文后各题所给的A、B、C和D四个选项中,选出可以填入空白处的最佳选项。

    Everyone loves getting cards on their birthday. For Bailey Sellers, the card from her father is a card, one that she'll 1 forever.

    Her father, Mike Sellers, died of cancer in 2013, just a few months 2 her 17th birthday. But her dad made sure he could still 3 her special day, even in death. Before his death he prepaid a flower shop to 4 flowers and a card to her every year on her birthday. The last flowers and 5 came last week, for her 21st birthday.

    In the card 6 came with this year's flowers, Mike Sellers told his daughter, “This is my 7 letter to you until we meet again. You are and will always be the most precious 8 I was given. I will still be with you through every milestone. Just look around and there I will be.”

    9 by her late father's gesture, Sellers posted a photo of the flowers, the card and an old 10 of her dad raising her up on his shoulder during a long ago trip to the beach.

    “Miss you so much daddy,” the post 11, with a little purple heart. The post moved thousands of people, who not only 12 it but also told their own stories of how they 13 the pain of losing a parent. Sellers 14 that pain; she said she became 15 after her father's death. So now she's studying psychology(心理学), hoping to be able to one day help people get out of the kind of 16 that once enveloped her.

    “He would be so 17 that he pulled off such a beautiful gesture, which offers an important 18 for all of us. He made people 19. He made people realize that they shouldn't take the people who 20 them for granted.”