题干

如图是小明设计的一个简易电子身高测量仪的示意图.其中,电源电压恒为6V,保护电阻R0=20Ω;R是一只固定着的、竖直放置的硬电阻棒、总长为40cm,其接入电路的电阻与接入电路的棒长成正比;金属杆cd和MP(右端P是滑片)与电路接触良好,电阻不计.小明用该测量仪对小聪、小英和小亮的身高进行了测量,其数据见下表.若已知小英测量时,滑片恰在电阻棒ab的中点位置,则根据题中提供的信息将表中数据填完整.从理论上分析,该测量仪的身高测量范围是____

小聪

小英

小亮

A表示数I/A

0.20

0.15

0.12

V表示数U/V

2.0

3.0

3.6

身高h/m

1.6

上一题 下一题 0.0难度 选择题 更新时间:2016-05-18 11:44:49

答案(点此获取答案解析)

1.4m~1.8m

同类题2

阅读下列短文,从每题所给的A、B、C、D四个选项中,选出最佳选项。

A

    Suppose you're in a rush, felling tired, not paying attention to your screen, and you send an email that could get you in trouble.

    Realisation will probably set in seconds after you've clicked “send”. You freeze in horrors and burn with shame.

    What to do? Here are four common email accidents, and how to recover.

    Clicking “send” too soon

    Don't waste your time trying to find out if the receivers has read it yet. Write another email as swiftly as you can and send it with a brief explaining that this is the correct version and the previous version should be ignored.

    Writing the wrong name

    The sooner you notice, the better. Respond quickly and briefly, apologizing for your mistake. Keep the tone measured: don't handle it too lightly, as people can be offered, especially if your error suggests a misunderstanding of their culture(i.e. incorrect ordering of Chinese names).

    Clicking “reply all” unintentionally

    You accidentally reveal(透露)to entire company what menu choices you would prefer at the staff Christmas dinner, or what holiday you'd like to take. In this instance, the best solution is to send a quick, light-hearted apology to explain your awkwardness. But it can quickly rise to something worse, when everyone starts hitting “reply all” to join in a long and unpleasant conversation. In this instance, step away from your keyboard to allow everyone to calm down.

    Sending an offensive message to its subject

    The most awkward email mistake is usually committed in anger. You write an unkind message about someone, intending to send it to a friend, but accidentally send it to the person you're discussing. In that case, ask to speak in person as soon as possible and say sorry. Explain your frustrations calmly and sensibly—see it as an opportunity to clear up any difficulties you may have with this person.