b . I o ) I o , d . 0 . 5 1 ^ , < I ^ < I ^ n b. Vd dilc d. 2, 3, 4 cqrc h. 2.5 d . 3
b. Cdch di€n cfia mang iliQn d. DO dm kh6ns khi
52. Ndi ddt v6 thidt bi lh ndi clA't an toin vi:
a. Ldm gidm nhd nhdt ddng rliAn qua ngudi khi ngrdi cham t,do thidt bi cham vd b. Ldm gidm nh6 nhdi ddng riiAn cham vd
c. Ldm gidm nhd nhA't ddng dign chqm rldt d. Ldm tdng diQn tr& cdch diAn cila thi|'r bi
53. Mang di6n dugc thdc hiQn b6o v€ ndi Oay ffung tinh khi tang sd ndi dt't lap l4i thi:
a. Tdng diQn dp budc b. Gidm di€n dp tiAfu xtic
c.Tdng diQn dp fiA'p xtic d. Gidm diQn dp budc
54. Muc clich cfia b6o vO ndi c1t't ld:
a. Bdo t,€ thidt bi di€n b. Ddm bdo cliQn dp cdc pha kh\ng tdng khi c6 I pha chqm ddt c. Giltm cti€n dp ti|'p xtic khi ctrym ddt d. ThiA't bi bdo t,A loqi tril doan mach bi sV cd 55. Dd loai tril hiQu rlng mdn che trong ndi ddt t4p trung, kho6ng c6ch giira cdc coc thddng bXng mdy lAn chidu ddi cqc (hi6u frng ldm r*r* Y*^"r/-
56. DiQn 6p tidp xric Utxl vd Utx2 khi ngddi chamgiSn tidp vio m?ng di€n 3 pha c1i6n 6p lJ= giSn tidp vio m?ng di€n 3 pha c1i6n 6p lJ= 380/220Y, di6n trd Rne=l kO, Rpl=lf), Rp2= l8f) voi Rp lndiQn trd n6i dAt cho thi0t bi, c6 gi6 tri li bao nhi6u?
a. fLt't = 360 V vd U62 = 20 Vb. Uut = 20 V vd U*2 = 360 \'/ b. Uut = 20 V vd U*2 = 360 \'/ c. (Jut = 21 V vd Ut"z = 2l V d. Ket qua khdc
57. Ddng diQn qua ngddi khi ngudi cham vdo I ctJccria mang <liQn 3 pha diQn 6p U = 380t220 V' tAn sd cria mang <liQn 3 pha diQn 6p U = 380t220 V' tAn sd f = 50 Hz, di6n trd c6ch diQn cfra dAy dan so vdi ddt R. = 10000 c), di€n dung c=l pF vd ttiQn tr6 Rne=l ko c6 gi6tti li bao nhi€u:
a . 4 3 . 7 m Ab. 100 mA