问题 选择题

电场强度的定义式为,则[ ]

A、该定义式只适用于点电荷产生的电场

B、F是试探电荷所受到的力,q是产生电场的电荷电量

C、场强的方向与F的方向相同,场强的大小E与F成正比,与q成反比

D、由该定义式可知,场中某点电荷所受的电场力大小与该点场强的大小成正比

答案

答案:D

阅读理解

阅读理解。

     Once, there was a man whose name was Tom. He loved his wife very much. A special day was

coming. It was his wife's birthday. Tom decided to buy something for her.

     The next day he went home and said to his wife, "I bought something for you." "Thank you!" said his

wife happily. "What have you bought for me?" "I've bought a gold ring. Here it is." He took it out for his

wife to see. Carelessly, he dropped it onto the ground. He began to look for it on the ground, but it was

dark in the house and he could not see anything. Then he went out and began to look for it in the street.

     He looked and looked. After a while, a friend came along. "What's the matter with you?" asked his friend.

"I am looking for my ring. It was for my wife. But I lost it just now." said the poor man."Where did you

lose it?""I lost it in my house.""You lost your ring in your house, but you are looking for it in the street. How

foolish you are!" "Ah," said the man,"But it is dark in my house. I will never find it there. Anyhow, here in

the street, it is much brighter, I can see everything more clearly."

     My dear friend, do you think Tom could find his gold ring in the street?

1. Whom did Tom buy a ring for?

A. His son.

B. His mother.

C. His wife.

2. Where did Tom lose his ring?

A. In the street.

B. In his house.

C. At his friend's house.

3. The man looked for the ring in the street because _______.

A. he lost it in the street

B. it was much brighter

C. his friend came up

4. The friend thought the man was _______.

A. foolish

B. clever

C. good

名词解释