For the loop l: 乐HF·a= To the surface si, we have I·d=l To the surface S,, we have( Contradiction(矛盾) I·d=0 Ampere' s law is invalid(无效 的) for the varying electromagnetic fieldH dl ? L  =    For the loop L: To the surface S1 , we have H dl I L  =    L S1 S2 I To the surface S2 , we have  = 0 L H dl   Contradiction (矛盾） Ampere’s law is invalid(无效 的 )for the varying electromagnetic field