题干

在图所示的电路中,电源电压保持不变

R2的阻值

电流表A的示数

R0

0.6安

R0+10欧

0.4安

R0+20欧

①若电阻R1的阻值为15欧,电流表示数为0.2安,求电阻R1两端的电压U1和电阻R1消耗的电功率P1

②若电阻R1的阻值未知,向右移动滑动变阻器R2的滑片P,每次移动时均使变阻器R2接入电路的阻值增加10欧,电流表A的示数分别如表所示,求电源电压U和R2为(R0+20欧)时电流表A的示数.

上一题 下一题 0.0难度 选择题 更新时间:2016-03-16 04:59:15

答案(点此获取答案解析)

解:①电阻R1两端的电压U1=I1R1=0.2A×15Ω=3V;电阻R1消耗的电功率P1=UI1=3V×0.2A=0.6W;

②当R0接入电路中时,则:U=0.6A×R0

当R0+10欧接入电路时,则:U=0.4A×(R0+10Ω);

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    The FRC is a world-class robotics competition that was first launched in the United States in 1989. It encourages students to improve their hands-on skills and creative capabilities.

    There are strict rules, limited resources and an intense six-week time limit before the competition. Teams of student should raise money, design a team brand and improve their teamwork skills, as well as build industrial-size robots to compete. The rules of the game include two groups, and each group has three teams. The group with the highest score wins the game.

    The seven teams who won the top prizes in the FRC  Shenzhen Regional will take part in the First Championship to be held in the United States next month.

    Yin Shifei, secretary general, said the competition not only enables students to improve their programming, decision-making and problem-solving skills, but also encourages them to cooperate and share with other people

    According to Yin, a Shenzhen team invited over 40 left-behind children to the city to watch the FRC game because they wanted to make education more equitable. And the left-behind children can get fair education. These children's parents are migrant workers in Shenzhen, but they are left behind i their hometowns.

    Shenzhen became the first city to host an FRC region in Asia last year, and another regional contest will be held in Shanghai this year.