如图电源的电压为U，R1=12Ω，R2=6Ω，开关S闭合后，电流表A1和A2的读_爱下问搜题

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问题填空题

如图电源的电压为U，R₁=12Ω，R₂=6Ω，开关S闭合后，电流表A₁和A₂的读数之比为______．

答案

从图可知，电阻R₁、R₂并联，电流表A₁测量通过R₂的电流，电流表A₂测量干路电流，

∵电阻R₁、R₂并联，

∴U₁=U₂=U，

据并联电路中电流和电阻的关系可知：

I1

I2

=

R2

R1

=

6Ω

12Ω

=

1

2

，

且对于并联电路的电流关系是：I=I₁+I₂，

∴

I2

I

=

I2

I1+I2

=

2

1+2

=

2

3

，

即：电流表A₁与A₂读数之比为2：3．

故答案为：2：3．

填空题

单词拼写。

根据所给汉语提示写出各句中所缺单词的正确形式

1. In the United Kingdom, smoking causes 121,000 _____死亡.

2. The plan_____ 相关to the project is under discussion.

3. 症状_____are signs that some one has an illness.

4. The_____ 观众was enjoying every minute of the performance.

5. Ye Xiaogang has received many_____ 奖 in China and in other countries.

6. He plays c_____ music, as well as pop and jazz.

7. Users become a_____ to crack cocaine much more easily if they smoke it.

8. In America, doctors work for themselves and hospitals are p_____ owned.

9. Many countries are thinking about b_____ smoking on public transport.

10. I tried to p _____what it would be like to live alone on an island.

填空题

1周角=( )平角=( )直角