题干

有一台输出电压按图1规律变化的交流发电机E,通过理想升压变压器T1和理想降压变压器T2向远处用户供电,如图2所示.现已知发电机的输出功率为1100W,T1的原副线圈匝数比为1:10,则下列说法正确的是(   )

A:发电机E所产生的交流电的电压表达式为e=220 2 cos100πt(V)

B:电流表的示数为0.5A

C:当用户消耗的功率变大时,输电线上消耗的功率也变大

D:若只增加T2的原线圈匝数,则发电机的输出功率将变大

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答案(点此获取答案解析)

B,C

同类题4

阅读下面短文,从短文后各题所给四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑

    Many years ago, Dad worked as a farmhand(农场工人).At that time, he had a horse. Every Saturday he 1to the town after dinner and spent a few hours on social 2 with other farmhands, such as drinking, chatting, and playing cards in the cafe. On Saturday evenings, the cafe was 3 because many farmhands were there. Before midnight Dad returned home on his horse, quite satisfied with his 4.In his words, he 5 thought of changing his job.

    At the age of 31,Dad married my mother who was a schoolteacher. In the following spring I came 6 into the world. Life became hard, so my mother felt 7.She told Dad that they must make a 8.

    My mother had 9 of how some famous persons, especially Thomas Edison who was born in a poor family, fought against fate and achieved greatness and 10.And she 11 that I would some day become a great leader 12 men or cities and Dad should be a successful businessman. So she 13 Dad to give up his job as a farmhand, sell his horse and 14 a small business of his own. And I went to high school and college. She even sent me abroad for 15 education when I graduated from college. Under the drive of my mother's hope, Dad and I 16 what we have today. Dad runs a big international 17 and I am a successful lawyer 18 great fame in my country,19 not a leader as my mother expected.

    Dad said, without my mother, we wouldn't be what we are today; at least, he would remain a farmhand.20 he got a lesson of life --- sometimes we really need drive from outside.