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例1一个电炉工作时在ts时间内产生的热量为Q,如果要使电炉产生2Q的热量,分析下列说法中正确的是()(A)把外加电压增大为原来的2倍(B)把电炉丝的电阻增大为原来的2倍(C)把电炉丝的电阻减为原来的一半(D)把外加电压、电炉丝的电阻及通电时间都增大为原来的2倍错解:根据焦耳定律Q=I2Rt,可知电炉丝通电时所产生的热量与电流强度的平方成正比,与导体的电阻成正比,与通电
Example 1 When an electric furnace is working, the amount of heat generated during the ts time is Q. If the electric furnace is to generate 2Q of heat, it is correct to say that (A) the applied voltage is doubled (B) Increase the resistance of the electric furnace wire by 2 times (C) Reduce the electric resistance of the electric furnace wire by half (D) Increase the resistance of the applied voltage, the electric resistance of the electric furnace wire, and the power-on time by two times. According to Joule’s law, Q = I2Rt, it can be seen that the heat generated by the electric furnace wire is proportional to the square of the current intensity and proportional to the resistance of the conductor,