D. CAM vaN deu dao dorrg vrii biOn do 1.5a.
Di = r,zcos[r oo ^ +) u ).
B. 70 mH. C. 99 ml-I. D.49.5 mH
Ciu '17. N4ot d6ng co khdng dong bd ba pha hoat ddng binlr thud'ng khi hi€u di6n the hiOu dung giira.hai daLr nrdi cudr dal la 100\'. Trong khi clo chi cir nrdt mang di€n xoal,chidu ba pha cio nrdt I'I{LiONC ]-HPT CHI lYlN Ot-tSp liA NOI -1'lll T'llLj'DAI I{OC LAN 4-(2010) - N{6n Vat lf - ma ai +i,t 5
md) ph6t ra tao ra. suAt di€n d6ng hi€u dung o rndi pha lA 173V. D€ dQng co'hoat d6ng binh thuong thi ta phdi mic theo c6clr niro sau dAy?
A. Ba cu6n ddy cua miiy ph6t theo hinli tarn gi6c, ba cu6n dAy cria d6ng co'theo hinh sao. B. Ba cu6n dAy cua rn6y phdt theo hinh tam gi6c. ba cu6n d6y cua ddng co tlreo hinh tam gi6c.
C. Ba cu6n dd1'cira m6y phd,t theo hinh sao, ba cu6n dAy cfra cl6ng co theo hinh sao. D. Ba cu6n dAy' c0a m6y ph6t theo hinh sao, ba cu6n dAy cira dOng co theo hinh tarn gi6c. Cdu,l8. Mdt buc xa clon s6c c6 buo'c song 2=0^44lun o trong thuy tinh (chi€t suAt cf,a thu,v tinh
Lrng voi bu'c xa d6 bing 1,50). Buc xa nay co mdr-r
A. larn. B. chdrn. c. d6. D. vdng.
Cliu -{9. Dung proton bin vao hat nhArr jfc clirng 1,€n d6 gAy phin [rng: 7r + ]Be --> X + iti.Bi6t ddng rrlng cfia cac hatp, X. iLi lAn lucrt ld 5,45lvIcV;4,\MeI/ vil,3,575MeV. Coi khdi lu'qng cdc hat tinh theo
zr eAn bing sO tttOi cira n6. G6c horr bo'i huirng chuyOn d6ng cira cbchatpvdXgAn dfng bing:
A.45('. B. l2oo. c.6o('. l. qou.
Cliiu 50. MOt nguon atn co c6ng sudt P : 0.4 (W) , drLoc coi ld rn6t nguOn di6rn,^ph6t song am trong
nt0t mtii trrtt)ng dang hucing vzi klttirrg lrAp rhLr im. ClLo'ng do Arn chuAn Io: l0-12 W/nr2. Mirc cr-Long
rlo arn tai nrol di6rn ciich xa rrgudn 20 rn Id
A.79 dB. 8.34.5 dB. C. 86 dfr. D. 7.96 dB.