电荷、电流、电能和磁能与时间的关系: g=go cos(at+o) 1=-goo sin(at+o)=Imx sin(at+o) E v cos (at+o) 2C2C Em=ll=loo sin(at+p)= sin (at +o) 2 2 2C 2 E=E+E=90=常数 2Cq = q cos(t + )  I q sin( t ) I sin( t ) = −   + = max  +  sin ( t ) C q Em LI Lq  sin (t  )  +  + =   =   =         cos ( t ) C q C q Ee  +  =  =     电荷、电流、电能和磁能与时间的关系： = + = = 常数 C q E Ee Em 2 2 0