试题与答案

下列有关电学实验的说法中,正确的是______(填选项字母) A.在“用描迹法画

题型:问答题

题目:

下列有关电学实验的说法中,正确的是______(填选项字母)

A.在“用描迹法画出电场中平面上的等势线”实验中,用恒定电流场模拟静电场

B.在“描绘小灯泡的伏安特性曲线”实验中,电流表采用内接法,滑动变阻器采用限流式接法

C.在“测定金属的电阻率”实验中,用螺旋测微器测量金属丝的直径,为减小误差,多次测量求平均值

D.在使用多用电表欧姆档测未知电阻时,不必每次换档都进行欧姆档调零.

答案:

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参考答案:C解析:本题考查要点是“混悬剂常用稳定剂”。(1)助悬剂:助悬剂是指能增加混悬剂中分散介质的黏度,降低药物微粒的沉降速度或增加微粒亲水性的附加剂。(2)稳定剂:为减少药物的不良臭味、提高物理...

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    风水学在中国文化中是一门源远流长的学问。其目的之一是教导民众,在山河大地之间,挑选一处适合人类生存的环境,并利用此环境, 积极奋斗,努力不懈,进而使长居此地的人们健康、平安又兴旺成功。虽然经过时间演化,有迷信成分,但里面却包含着中国古代朴素地理的思想。

阅读下列材料,回答问题。

材料一

穴居时代的居住风水——“未有宫室之时,因‘陵穴’掘穴而处之;乃圣王虑之,以为掘穴,则冬可避风寒”。

材料二

殷商时代的居住风水“攻位于讷”(讷:河水内湾环抱处,为凸岸)。

(1)读材料一和图甲,分析穴居时代人们在选择开凿居住洞穴时需考虑哪些自然环境因素并说明理由。

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(2)根据材料二和图乙、丙,分析“讷位”(凸岸)对农业生产、取水、安全等产生的影响及原因。

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