题目

两块量程均为0~10mA但内阻未知的电流表A1、A2，现通过如图所示电路来测量其中一电流表的电阻。（1)连接电路，将滑动变阻器R1的滑片滑到最_________端（填“左”或“右”），闭合电建S；（2）将电阻箱R2调到某一阻值，然后调整滑动变阻器R1滑片的位置，使两电流表均有较大幅度的偏转；（3）记录此时两电流表的读数I1、 I2和电阻箱的阻值R2；（4）根据以上数据可以得到电流表_________（填“A1”或“A2”）的阻值，若I1=6.0mA，I2=9.0mA，R2=23.6Ω，则该电流Mr and Mrs Martin live in New York. Mr Martin is a doctor and his office is in New York. Mrs Martin teaches music at a school in New York. They have two sons. Their sons’ names are Ted and Roy. Ted is twenty years old. He is now in Taiwan. He studies Chinese there and he loves his school very much. Roy is thirteen years old. He goes to middle school. He likes sports very much. He likes swimming best and he can swim very fast in his class. He wants to be the best swimmer in his school. 1. What is Mr Martin?   A. He is an American.                          B. He is a teacher.   C. He is a doctor.                        D. He lives in New York. 2. What does Mrs Martin teach?   A. English         B. Music             C. Chinese            D. Swimming 3. How many people are there in his family?   A. Three.          B. Four.              C. Five.              D. Six. 4. Where does Ted study now?   A. China.          B. England.           C. New York.         D. Taiwan. 5. What does Roy want to be?   A. He wants to be a doctor.   B. He wants to teach music at a school.   C. He wants to go to Taiwan to study Chinese.   D. He wants to be the best swimmer in his school.