题干

在“测量小灯泡电功率”的实验中,小灯泡的额定电压为2.5V.

(1)连接电路时,开关应____ .

(2)图甲是小刚所接的实验电路,其中有一根导线连接错误,请你在错误的导线上打“×”,并用笔画线代替导线画出正确的接法____ .

(3)故障排除后,小刚进行了实验,根据测出的数据,画出了小灯泡电流、电压变化的关系图象,如图乙所示,由图象可知小灯泡的额定功率为____ W.

(4)分析图象还可以发现,小灯泡灯丝的电阻随电流的增大逐渐____ ,原因是____ .

 

上一题 下一题 0.0难度 选择题 更新时间:2018-10-19 09:34:09

答案(点此获取答案解析)

断开,,0.5,变大,灯丝的电阻随温度升高而增大

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    A study shows that one million lives might be saved each year if people wash their hands with soap(肥皂) often. It also says that hand-washing with soap could be among the best ways to reduce diseases. Doctors say many diseases can be prevented from spreading by hand-washing. These include the common cold, influenza(流行感冒), hepatitis(肝炎), infectious diarrhea(腹泻) and so on.

    Doctors say you are easy to catch a cold by touching your nose or eyes after someone nearby has sneezed or coughed. Another reason to catch a disease is to eat food prepared by someone whose hands were not clean.

    They also say that hand-washing is especially important before and after preparing food, before eating and after using the toilet, after touching money and sneezing or coughing. The most helpful way is to wash them together while using soap and warm water. You do not have to use special soap. Be sure to wash all areas of the hands for about ten to fifteen seconds.

Title : Basic Knowledge of hand-washing

Diseases are

under ____.

People can____ many diseases from spreading by hand-washing such as the common cold, influenza and so on.

The____ of

becoming sick.

●Touch your nose or eyes after someone nearby has sneezed or coughed.

●Eat food prepared by____ hands.

____to do hand-washing.

●Before and after preparing food.

●Before eating and after using the toilet.

●After touching money and sneezing or coughing.

How to do

hand-washing.

●Wash them together while using soap and warm water.

●Wash all areas of the hands for about 10-15 seconds.