在八年级物理人教版的伏安法测电阻中,待测电阻选用了小灯泡,我认为应该先测定值电阻的阻值,然后再测小灯泡的阻值比较好。学生刚刚学习欧姆定律公式I-U/R的导出式R=U/I,做题时非常容易出现只看表面公式而忽略物理量本身的物理含义的问题。如:下列对于欧姆定律的公式和导体的电 In the eighth-grade physics teacher’s volt-ampere measuring resistor, a small light bulb was chosen for the resistance to be measured. I think that the resistance of the value resistor should be measured first, and then the resistance of the small light bulb should be measured better. Students have just learned the formula R-U/I of the formula I-U/R of Ohm’s Law. When doing the problem, it is very easy to see the surface formula and ignore the physical meaning of the physical quantity itself. Such as: The following formula for Ohm’s law and the electricity of conductors