L3t E4i Hgc Su Ph4m TpHCM Khoa Vft Lf pd rni lin r M6n: EiQn DQng Lgc ThdiGian: 120 phrit Cdu l: DiQn tir trudng (3il) l. vi6t hp phuong trinh Maxwell trong chdn kh6ng (dang vi ph6n) vi cho ui6t y nghia vft lf tirng phuong trlnh 2. xudt phat tir phuong trinh divE = L trongchdn kh6ng, h6y x6y dung phuong trinh tuong tu trong mdi trudng "r, jntU. 3. Ldy vi du tl6 chfng t6 rliQn tir trudng ld mQt dang t6n tgi cria vflt ch6t. Cdu2: Sdng tliin tir tg do (2rt) l. Thgc ti6n ndo cho thdy ring tliQn tir trudng c6 th6 t6n t4i rtQc lfp. phdn tich ngin gqn di5 d6 chung minh. 2. Tir hQ phuong trinh Maxwell, hdy chring minh lugn di6m tr6n bing c6ch giai hQ ,;' ,-^,+* nllu*q1g trinh Maxwell' : gdu 3: Eipn Th6 vn NEng Luflrg itiQn trudng cfra qui cAu tich ttiQn (3iI) MQt qui cAu b6n kinh R, tich dien dAu theo th6 tich, mat dO p = const, hQ s6 diQn mQi b6n trong vd ngoii qui cAu dAu ld a. l. Tim phf;n UO eien thti tr6n todn kh6ng gian 2. Tinh diQn dung cta quA cAu 3, Tfnh ndng lugng diQn trulng cira qui ciu cdu 4: Moment tir vi cim {'ng tir cia qufr cAu tich iliQn xoay (2rI) MQt m{t cAu b6n kfnh a,. tich ttiQn dAu v6i t6ng <liQn tich ln e. eua cAu xoay quanh trsc cfia n6 v6i vfln t6c g5c Z l. Tinh vecto moment tir cira qui cAu 2. Tfnh Vecto c6m ring tt t?i tem mflt cAu. ' Thf sinh kh6ng clugc sri dpng tdi liQu 'Ci6m thi kh6ng gi6ithfch dA thi -LT' .l-f€il ,1 / 0T" Cfd+"4 $d*& $* Pt . cira qui cAu 2. Tfnh Vecto c6m ring tt t?i tem mflt cAu. ' Thf sinh kh6ng clugc sri dpng tdi liQu 'Ci6m thi kh6ng gi6ithfch dA thi -LT' .l-f€il ,1 / 0T" Cfd+"4 $d*&. vflt ch6t. Cdu2: Sdng tliin tir tg do (2rt) l. Thgc ti6n ndo cho thdy ring tliQn tir trudng c6 th6 t6n t4i rtQc lfp. phdn tich ngin gqn di5 d6 chung minh. 2. Tir hQ phuong. todn kh6ng gian 2. Tinh diQn dung cta quA cAu 3, Tfnh ndng lugng diQn trulng cira qui ciu cdu 4: Moment tir vi cim {'ng tir cia qufr cAu tich iliQn xoay (2rI) MQt m{t