题干

如图所示,在竖直向上的匀强磁场中,水平放置着一根长直流导线,电流方向指向读者,a、b、c、d是以直导线为圆心的同一圆周上的四点,在这四点中(   )

A:a、b两点磁感应强度相同

B:a点磁感应强度最大

C:c、d两点磁感应强度相同

D:b点磁感应强度最大

上一题 下一题 0.0难度 选择题 更新时间:2019-09-06 12:28:38

答案(点此获取答案解析)

D

同类题2

阅读理解

    We live in the world full of colours. Does a colour have weight? If you say “no”, you are wrong. If you don't believe, you may do an experiment.

    First, put two objects with the same weight into two boxes. Then cover the boxes. Third, wrap one box with a red piece of paper, the other woth a white piece of paper. Now hold the boxes with your hand one by one. It is certain that you think the red one is a little heavier.

    Why? A scientist found that different colours have different weight in a man's mind. So he did many tests and at last he found that every colour has its own weight in our mind and their order is the same. The heaviest colour is red, then blue, green, orange, yellow and white.

    The scientist told us that colours also have smell. Can you smell the colour? Of course not. Then why did the scientist say so? That is because every colour stands for a kind of light with a certain wavelength, and it reaches our brain through sense organs.

    According to this discovery, scientists say that people accept the colours they like, and refuse the colours they hate. So your body and mind will be healthy by using the colours you like. Or you'll be nervous or even get ill. For example, if you stay in a room with red windows, wallpapers and furniture for two hours, you'll feel you have been there for four hours. But if the room is blue, you'll feel you have been there for only an hour. Another example, if a person walks out of a red room and into a blue room, his temperature will fall. That means our body temperature will change with different colours.

同类题4

任务型阅读

    Teachers love to put students into teams.____ Why? Because they know the responsible team members will come through for a good grade.

If you are teamed up with a student who is lazy, the worst thing you can do is let it get you down.____ and it might create a positive change in your partner!

    Try these tips for working with a slacker(懒虫).

    Be excited and provide a good example. Your slacker may be a good person who has developed bad work habits. You may be able to teach your partner some valuable skills for a successful future.

    Think rewards!____ For instance, you could promise to make cupcakes for the next work meeting and encourage your partner to bring a good snack.

    Make some time to sit with your partner and establish a set of work rules and deadlines. Don't quarrel, though. Make it clear that you would like to establish rules to keep you both on track.____ Keep a record of your rules, your initial meetings, and your work. When it becomes obvious in the records that you're doing all the work, talk with the slacker.____

A. Don't let the anger and pain defeat you.

B. Come up with a great reward for meeting some goal.

C. Instead, take some steps to encourage your partner to work.

D. Unavoidably one or more members will try to do nothing.

E. Start out by giving your partner a clear task with a deadline.

F. Show him/her the evidence and suggest he or she pick up the pace.

G. Think about the future and the fact that you are going to be rewarded.