questions of power system

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question 1. the insulation resistance of cable of length 10KM is 1Mohm. For a length of 100Km of                         the same cable, the insulation resistance will be...
                            
                                                  R1L1= R2L2
                                                  

                                              1*10= R2*100

                                               R2  =0.1Mohm ANSWER

QUESTION2.  For a 500Hz frq. excitation, a 50 KM long power will be modeled as
                                           
                                                   
                                                 lemda = v/f
                                                
                                                          v=50*500
                                                            = 25000 Km
                                  
                                              velocity for long transmission for long line > 10000Km
                                                
                                                      So we use long line 

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