问题
填空题
灯L1标有“6V 6W”,灯L2标有“6V 3W”.把它们串联在电压为9V的电源上,灯L1的功率是_______W.
答案
1.5
题目分析:已知额定电压和额定功率可求电阻,根据总电压求出电流,再算各自实际功率.
.
.
,
灯L1的实际功率P实=I2R1=0.52×6W=1.5W.
点评:本题考查电功率的计算,以及有关公式的应用.注意灯泡的电阻是不变的.
灯L1标有“6V 6W”,灯L2标有“6V 3W”.把它们串联在电压为9V的电源上,灯L1的功率是_______W.
1.5
题目分析:已知额定电压和额定功率可求电阻,根据总电压求出电流,再算各自实际功率.
.
.
,
灯L1的实际功率P实=I2R1=0.52×6W=1.5W.
点评:本题考查电功率的计算,以及有关公式的应用.注意灯泡的电阻是不变的.
Skylar is a four-year-old girl. When she learned about Disneyland from TV last July, she began to money. She hoped that she could there some day. One day her parents surprised her with a trip to Disneyland, but they didn’t her to use the money in her money box.When they returned, it was Chrismastime. Skylar decided to buy gifts her money. But when she a show on TV about a local homeless shelter(收容所) Called “The Road House”,she asked her mother again and again “homeless” meant and why those children needed warm clothes. She couldn’t get the homeless children off her . Before Christmas, Skylar’s mother took her to a to buy gifts. Instead of buying gifts for herself or her family, Skylar a coat and some socks for a little girl in the shelter. When Skylar got home, she the things she had bought in a beautiful box.Skylar was very at waiting for Christmas! She was not thinking about Santa Claus or the gifts she would . She was thinking about going to the shelter and giving gifts to a child.On Christmas Eve, Skylar and her family drove to the shelter and she gave the beautiful to a girl, Skylar was very happy helping someone else, her family decided to make the journey to the homeless shelter a tradition. What a beautiful heart young Skylar has!
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