天天发现:每天晚上7点到9点,小区处于用电高峰期时,家中的电灯相对较暗;而到了晚上11点以后,电灯又会变得亮一些。他对此产生了疑惑。通过询问老师,天天了解到:“不同时段,电路中的用电器数量不同,其总电阻也不同。”对这种说法天天能够理解,家庭电路中各用电器之间相互并联,电路中的用电器数量不同,其并联后的总电阻也 Every day found: every day from 7:00 to 9:00, the district is in the peak of electricity, the lights in the home is relatively dark; and by 11 pm, the lights will become brighter. He was puzzled. By asking the teacher every day to understand: “At different times, the circuit in the number of different appliances, the total resistance is also different.” To this statement every day to understand that the home circuit between the appliances in parallel with each other in the circuit The number of different appliances, the total resistance after the parallel