( 多选 ) 如图 338 所示电路中, L 为电感线圈, R 为灯泡,电流表内阻为零,电压表内阻无限大,交流电源的电压 u = 220 sin 100π t V ,若保持电压的有效值不变,只将电源频率改为 100 Hz ,下列说法正确的是 ( ) A .电流表示数增大 B .电压表示数增大 C .灯泡变暗 D .灯泡变亮 A.B.C.D. D
【简答题】Peer(同龄人)Pressure Peer pressure is just part of the challenges in life. 66 If you need further guidance, this article might help you. It provides three effective tips to deal with it: Be with friends ...