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根据公式 P=UI,测量小灯泡的额定功率是初中学生应掌握的一项基本技能.有如下的实验题目:现有电压表、滑动变阻器、已知阻值的定值电阻R_0、额定电压为2.5V 的待测灯泡、电池组、开关各一个,导线若干.利用以上器材测量小灯泡的额定功率.要求:(1)画出电路图;(2)写出实验步骤;(3)写出测量小灯泡的额定功率的表达式.分析1 根据公式 P=UI,实验器材中应该有电压表和电流表,但题目没有提供电流表,而是多了一个定值电阻 R_0,所以我们的基本思路应该是:将小灯泡
According to the formula P=UI, measuring the rated power of a small light bulb is a basic skill that should be mastered by junior high school students. There are the following experimental topics: existing voltmeter, sliding rheostat, known resistance value setting resistor R_0, rated voltage One 2.5V light bulb to be tested, one battery pack, one switch, and several wires. Use the above equipment to measure the rated power of the light bulb. Requirements: (1) Draw the circuit diagram; (2) Write the experimental procedure; (3) Write the measurement Expression of the rated power of a small bulb. Analysis 1 According to the formula P=UI, there should be a voltmeter and an ammeter in the laboratory equipment, but the problem is not to provide a current meter, but a fixed value resistor R_0, so our basic idea should be : Will be a small light bulb