Question

為了測量量程為3V的電壓表V的內阻（內阻約2000Ω），實驗室可以提供的器材有：                       

電流表A₁，量程為0.6A，內阻約0.1Ω                                                                             

電壓表V₂，量程為5V，內阻約3500Ω                                                                             

變阻器R₁阻值范圍為0﹣9999Ω                                                                                      

變阻箱R₂阻值范圍為0﹣99.9Ω                                                                                       

滑動變阻器R₃，最大阻值約為100Ω，額定電流1.5A                                                       

電源E，電動勢6V，內阻約0.5Ω                                                                                    

單刀單擲開關K，導線若干．                                                                                          

                            

（1）請從上述器材中選擇必要的器材，設計一個測量電壓表V的內阻的實驗電路，在圖1方框中畫出電路原理圖  （    電路原理圖中的元件要用題中相應的英文字母標注），要求測量盡量準確．                

（2）根據(jù)你所畫的電路原理圖在圖2所給的實物圖上畫出連線．                                   

（3）說明實驗所要測量的量：                                                                           ．寫出計算電壓表V的內阻R_V的計算公式為R_V=                                                                                                                ．

                                                                                                                                       

Answer 1

（1）（2）

（3）電壓表V的示數(shù)U、電壓表V₂的示數(shù)U₂、電阻箱R₁的讀數(shù)r₁，電壓表的內阻為R_v=