题目

如图所示，闭合开关S，将滑动变阻器R2的滑片向a端滑动，电流表的示数将 ；电压表与电流表的示数之比将 ．（填“变大”、“变小”或“不变”） 答案：【考点】欧姆定律的应用；影响电阻大小的因素． 【分析】两电阻串联，电压表与R1并联，电流表串联在电流中；当滑片向a端滑动时，分析其接入电路中电阻的变化，根据电阻的大小与其两端电压和通过的电流无关，大小等于两端电压和通过的电流的比值． 【解答】解：滑片向a端移动时，滑动变阻器语篇翻译 阅读下面的短文，将画线部分译成英文或中文。45I often hear some students say English is difficult, and it gives them a headache. So they can’t learn it well. 46. 但是英语对我来说很容易。 I’m good at it. I’m very glad to tell you something about how I study English.47I think an interest in English is very important. When I was in Grade Seven, we had a new subject – English. It was fresh for me. I was interested in it, so I worked hard at it. Soon we had an English exam and I got a very good mark. How happy I was! 48After that, I learned English harder and harder. Our English teacher often teaches us English songs, the songs sound nice. I often think how interesting English is!49我已经学习英语两年多了。 I always keep the first position in our school. From these words, I hope every student can learn English well.1._________________________________________________________________2._________________________________________________________________3._________________________________________________________________4.________________________________________________________________5._________________________________________________________________