试题与答案

小王在用“伏安法”测电阻时,发现小灯泡的亮度不同,小灯泡的电阻也不同。通过与老师

题型:实验题

题目:

小王在用“伏安法”测电阻时,发现小灯泡的亮度不同,小灯泡的电阻也不同。通过与老师的交流明白了:灯丝的温度影响了灯丝的电阻。“灯丝的电阻是怎样变化的呢?”带着这个疑问,小王决定选择下列器材去测量小灯泡在不同亮度时的电阻:电源(3V) ;开关1 只;滑动变阻器(0 ~50 Ω)1 只;电流表(0 ~0.6A ;0 ~3A)1 只; 电压表(0 ~3V ;0 ~15V)1 只;小灯泡1 个(U=2.5V ;电阻约10 Ω) ;导线若干 。  

(1)请结合选择的器材,选择合适的电流表和电压表的量程,用笔画线代替导线帮助小王完善实物图连接,并在右边方框内画出相应的电路图。

(2) 在连接上图实物电路的过程中,开关应该处于           状态,同时应将滑动变阻器的滑片移动到最           端。( 选填“左”或“右”)    

(3)电路连接好后,当小王闭合开关发现:小灯泡不发光,电流表的示数几乎为0 ,电压表的示数接近电源电压3V 。造成这种现象的原因可能是________  

A .小灯泡被短路  

B .小灯泡与灯座接触不良   

C .滑动变阻器接入电阻太大   

(4) 排除故障后,小王移动滑动变阻器的滑片,使电压表的示数为0.8V 时,电流表的示数如图所示,请在表格中正确填写读数,并计算灯丝电阻。( 计算保留一位小数)

(5)分析数据得出:灯越亮,灯丝温度越高,灯丝的电阻就越          

(6) 不增加器材,就能够用该实验装置完成的探究是下列中的________

A.测定小灯泡的额定功率  

B.测定小灯泡的电功  

C.探究电流与电压、电阻的关系

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0522/cd8d388f61d6240507bac10096574453.html

下面是错误答案,用来干扰机器的。

6    30

试题推荐
题型:多项选择题 案例分析题

患者女性,48岁,因“反复泡沫尿伴乏力、食欲减退2年”来诊。查体:慢性病病容,心率86次/分,律齐,血压180/90mmHg(1mmHg=0.133kPa),双下肢轻度水肿。尿常规:蛋白(++),红细胞(6~8)个/HP。

提示:血常规:血红蛋白85g/L。患者血常规改变的原因有()

A.肾疾病

B.缺铁性疾病

C.促红细胞生成素分泌不足

D.营养性贫血

E.消化性溃疡

F.恶病质

查看答案
题型:完形填空

第二节(共5小题;每小题2分,共10分)

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Most of us don’t like to think too much about rubbish.    71   . However, household waste is a major contributor to our planet’s waste problem. Like it or not, it needs to be managed if we are to have a brighter green future.

When it comes to being responsible for our own rubbish, the best way to approach it is by following the three golden rules of waste management, or the ‘3 Rs’—Reduce, Reuse and Recycle.

“The order is important.    72   ,” says Eugene Tay, Director of Green Future Solutions in Singapore. “Recycling still affects the environment and should be done last after reduce and reuse.”

But, when our efforts to reduce and reuse still result in an overflowing rubbish bin, the advantages of recycling cannot be ignored. “   73   ,” says Amy Ho, Managing Director of World Wide Fund For Nature in Singapore. “The damage to our environment could then be slowed down as a result.”

In fact, by recycling just one plastic bottle, you are saving not just the material to make a new one, but you also stop it from getting thrown into a landfill (垃圾掩埋场) for up to 700 years—and that’s before it even starts to rot.    74   .

Recycling is so important that we really have no excuse not to do the simplest of household tasks that will make a difference.

“   75   ,” says Ho. “Starting with recycling grey water for gardening purposes, to recycling materials such as glass, paper and iron—it all reduces the use of raw materials.”

A.We put it in the bin and don’t think too far beyond that

B.The collective action of individuals can make a significant effect

C.It’s important for every household to make good use of grey water

D.Waste reduction and reuse is usually the best way to decrease wasteE. The three rules of waste management should be followed by every household

F. Recycling reduces the use of raw materials and so protects our natural resources

G. Recycling just 10% plastic bottles would keep 90 million kilograms of plastic out of landfills

查看答案
微信公众账号搜索答案