论文部分内容阅读
白炽灯是利用电流热效应的原理来工作的,其灯丝阻值受温度的影响较大。一只“220V 40W”的白炽灯在冷态时电阻约100Ω,而在正常工作时(热态)电阻为1210Ω,其灯丝阻值相差竟达10多倍。灯丝阻值变化的问题不仅在实验探究题中出现,近两年在中考电学计算题中也有体现。灯丝阻值变化情况一般通过图像或表格呈现出来,由于多数同学对灯丝电阻变化这一隐含过程没有思想意识,仍然沿用以往分析计算灯泡时忽略灯丝电阻受温度影响(即
Incandescent lamp is the use of the current principle of thermal effects to work, the filament resistance by temperature greater impact. A “220V 40W ” incandescent lamp resistance of about 100Ω in cold, and in normal operation (thermal) resistance of 1210Ω, the filament resistance as much as 10 times the difference. The problem of the change of filament resistance not only appears in the experiment question, but also in the calculation of the middle school exam in the recent two years. Filament resistance changes are generally presented through the image or table, as most of the students on the filament resistance change implicit process without thinking, still use the previous analysis of light bulb ignores the temperature resistance of the lamp resistance (ie