问题 选择题

下面关于电场的性质说法正确的是(  )

A.电场强度大的地方,电荷所受的电场力一定较大

B.电场强度大的地方,电场线一定较密

C.匀强电场中两点的电势差大小仅与两点间的距离有关

D.两个等量异种点电荷连线的中点处场强为零

答案

A、电场强度大的地方,电荷所受的电场力与电量的比值越大,而电场力不一定较大,故A错误;

B、通过电场线的疏密来体现电场强度的大小,故B正确;

C、沿着电场线方向电势在降低,所以匀强电场中两点的电势差大小仅与沿电场线方向两点间的距离有关,故C错误;

D、两个等量同种点电荷连线的中点处场强为零,根据库仑定律可得,此处的电场力为零.故D错误;

故选:B

阅读理解

Alice was now in a long dark room with doors all round the walls, and she could not see the White Rabbit anywhere.

She tried to open the doors, but they were all locked (锁上的). “How will I ever get out again?” she thought sadly. Then she saw a little glass table with three legs, and on the top of it was a very small gold key. Alice quickly took the key and tried it in all the doors, but she couldn’t open any.

Then she saw another door, a door that was only forty centimetres high. The little gold key unlocked this door easily, but Alice couldn’t get through it—she was much too big. So she lay on the floor and looked through the open door, into a beautiful garden with green trees and bright flowers.

“I’d like to be out there—not in this dark room. Why can’t I get smaller?” It was already a very strange day, and Alice was beginning to think that anything was possible.

After a while she locked the door again, got up and went back to the glass table. She put the key down and then she saw a little bottle on the table. Round the neck of the bottle was a piece of paper with the words DRINK ME in large letters.

“It can be dangerous to drink out of strange bottles,” she said. “What will it do to me?”She drank a little bit very slowly. The taste was very nice and very soon Alice finished the bottle.

“I think I’m getting smaller and smaller every second.” And she was. “And now,” she said happily, “I can get through the little door into that beautiful garden.”

She ran at once to the door. Then she remembered that the little gold key was back on the glass table. She ran back to the table for it, but she was now much too small! The key was high above her, on top of the table. She tried very hard to climb up the table leg, but she couldn’t do it.

At last, tired and unhappy, she got angry with herself. Soon she saw a little glass box near her on the floor. She opened it, and found a very small cake with the words EAT Me on it.

Nothing could surprise Alice now.

小题1: Where did Alice find the little gold key according to the story?

A.In the garden .

B.On the floor.

C.In the glass box.

D.On the glass table.小题2:We can learn that Alice felt a little ______ from the underlined sentence.

A.proud

B.angry

C.afraid

D.excited小题3:Which is the right order of the events according to the story?

① Alice saw a little glass box near her on the floor.

② Alice came to a long dark room.

③ Alice saw a beautiful garden with green trees and bright flowers.

④ Alice drank out of the little bottle and became small.

⑤ Alice took the little gold key and opened the small door.

A.②⑤③④①

B.②④⑤①③

C.②①⑤④③

D.②③④⑤①小题4:What do you think Alice will probably do at the end of the story?

A.Wait for the White Rabbit.

B.Eat the small cake.

C.Climb up the table leg again.

D.Sit on the floor and cry.

单项选择题