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近年来在中考、高考统考试题中,有些题出现了这样那样的错误,应该引起足够的重视。笔者仅以考题中出现过的三例错题,加以分析 [例1]一只标有“220V 40W”字样的灯泡,把它接在110伏特的电压下,它的实际功率是…………………………。物理学中的一切理论都必须和实验相符。可是此题按教科书本意,即在灯丝电阻不随电压改变而改变的情况下解为10W,但实验测得的数据约为15W。显然理论值和实验不相符,笔者认为象这种理论和实际出入较大的试题以后不应该再出。因灯丝温度变
In recent years, in the examinations for entrance examinations and college entrance examinations, some of these questions have appeared in this type of error and should be given sufficient attention. The author only analyzes the three wrong cases that have appeared in the exam. [Example 1] A bulb labeled “220V 40W” is connected to a voltage of 110 volts. Its actual power is...... .................................. All theories in physics must match the experiment. However, this problem is in accordance with the textbook intention, that is, the filament resistance does not change with the voltage change and the solution is 10W, but the experimentally measured data is about 15W. Obviously, the theoretical value is inconsistent with the experiment. The author thinks that such a theory and actual examination questions should not come out after a larger test question. Due to filament temperature change