题目

His grandmother is well because she often __________.A. exercises             B. smokes         C. sleeps D. sings 答案：A一只小灯泡，在正常发光时，灯丝两端的电压和电阻分别是2.5V与10Ω．若王小冰同学只有电压为5.5V的电源，要使小灯泡正常发光，需要在电路中接入一个电阻．问：（1）这个电阻应如何连接在电路中？电阻的阻值应是多大？（2）这只小灯泡正常发光1min，消耗的电能是多少？