题目

单词拼写 61. There are a few            (比赛) in our school this term. 62. There are only         (45) students in his class. 63.          (物理) is my favorite subiect. 64. My            (美国的) friend is going to visit me next vacation. 65. My mother is            (离开) for Shanghai next week. 答案：在用电压表和电流表测小灯泡电阻的实验中．（1）该实验原理是_________．（2）在方框内画出实验的电路图． （3）将图中的电压表连入电路．（4）电路连接无误后，闭合开关，电压表和电流表的示数如图所示，则通过灯丝的电流为_________A，小灯泡两端的电压为_________V，小灯泡的电阻为_________Ω． （5）若滑动变阻器的滑片向左移动，电压表的示数将 _________ （选填“变大”、“变小”或“不变”）．小灯泡的亮度将 ________ （选填“变亮”、“变暗”或“不变”）．