题目

Do you want to be a leader? Will you become a great leader? Well, to answer these questions,you need to have some important qualities of a great leader.A great leader takes charge. 【1】 They motivate their people to do what they think cannot be done. They motivate their people to grow! And when it is all said and done, they have motivated their people to succeed.A great leader sets a good example to his people. 【2】 It has something to do you’re your actions and your attitude. A great leader leads through his actions and his attitude. He does not sit on the sidelines, but takes part in如图所示，匀强磁场的磁感应强度B=0.5T，匝数为n=50的矩性线圈，绕转轴OO'垂直于匀强磁场匀速转动，每匝线圈长为L=25cm，宽为d=20cm，ω=100πrad/s，在匀速转动过程中，从线圈平面经过图示位置时开始计时，求：（1）写出交流感应电动势e的瞬时值表达式；（2）若每匝线圈本身电阻r=0.02Ω，外接一只阻值为9Ω的用电器，使线圈和外电路构成闭合电路，写出交流感应电流I的瞬时值表达式；（3）将一交流电压表接在R两端，电压表示数为多少？