Tiêu đề wEMT April 2023.pdf ✅

[Time: 3 Hours] SEM-111 Diploma Exam 2022 (Odd) (Electrical Engine:ering) (T~eory) Electric Motors and Transformers (2020304) [Max. Marks: 70] '. - All questions are compulsory. (~ -s1.,- ~ t'I) Marks are mentioned on the right side of e~ch quest~o,n. (a:Ai B"'fi,;"1' *~am~~ t'I) ·Group (A) (~ -lO Q.l Choose the most suitable answer the following options. ('1cdRliii ~ ~ cfiT ~ ~~fl): - i./ A transformer does not transf~'rm: (~~-------ctil ~q,~fh1 ~~t:) (a) Power (b) Voltage / ~ ' , {fi) (~) 1 ·1· Transformer act,ion requires--------. . (~~:~~-------'-~ii) (a) Constant magnetic flux (c) Current (mu) (c) Alternating electric flux (d) None of these (~~~~) (fro~~)-- (b) Increasing magnetic flux (~?!~~) (~~~) ·, ,Jdl Alternating magnetic flux (~~~) iii. Oil is used in a transformer for the purpose of:(qf\011f'l51 q m, cf;T ~ f.rq ~ ~ ~ ~ -;oiTcTT t:) (a) Insulation . (b) Cooling />, Both (a) and (b) (d) None of these (~ TitT-r) (~) ((~) 3fR (ar) -&.rr) (~ ~ .Af ~) iv. In step-d~wn transformer the diameter of wire of secondary winding is .. .. ..... . Primary winding. (~-~ ~ ~ ~ -~ ~ olt cf;T o!ira, ~~~cm: -------~ti) (1*2'0=20: (a) Toe,same as ··.~)Less than that of JI;) More tha~ that of . (~'ilUiR) (~-~) ' (~ ~) (d) Both (a) and (b) ((~) ~(if)~) . v. The three phase transfoimer which is more feasible to use in the distribution end should be . (a) Scott (~) (~ qft:011f'l51 ""'~-urr qr~~~~~~ t ~:.-.. ----- wrr.) (b) Delta-Delta f,) Delta-star (rn:r--mr) c-mr~) · vi. Welding trarisforme~s a: (~ qft:u11f'l51 ---------- ml ti) (a) Ste~--up _transforiner fQ) Step-do~n transfonner (c)'Both (a) and (b) (~-J;q' ~) ·. (Rlf~m;f ~} «~) 3ffi (if) tr-IT) vii. Scott connections are .used to convert. (9) Star-delta ("RR--mf) (d) None of these (~~~~) (~ lf7ITTr;f ~ ~~~~~~~ti) (a)Tl#ee -phase supply to single phase supply .A~~-1~:at. ~it) Page 1 of S EDD013455B l C926233B5B41AFD679D8E 2020304 sbte.way2poly.in
'V V' . , . , .... ~, .,,, ,/ ,":- (''....::... : ..... ., ., ,I~.._ I /'-/,· -~" ~ / Total number of windings present in an Auto-Transforfuer are-----:::':'-~ , '../ ..;,· ', < c~ -mlt~~~¥f ~~~ -----------,1). -- ,), . ,.,::>; , ,_/4c~·- (,.' ' , 4.:; . /: ... , ,,./'•··~ f-~----' Th d · d' f hl h f h • • ... , ·, k pt closed? 1 •• "·, e secon ary wm mg o w c o t e followrng transformer 1s al'o/,ays e 1 , ') ,. .. ::·; / viii. (a) 4 ix. (f.11 ... ~ft.a ~-«~~' ADnaturc speed, Armature current _ --2:. (c) Arm~1 ~re emf, ~ ature speed (aiM~ ~mu) . (~fcl-.qy_ ~ ,;.~-:;m:r) An-•ilF- current, Armature emf (d) Annature s1ie'c:d Armature emf. ~ ',) ~- ~ ) (~~'2-~fct.qf, ~) TIie narrow poles placed in between__~the ~ain poles of a D~C. machine are called . . ~ ~ ~ ~~~~~-------~ti)' (~ Gf) r) Inter pole (W ~) ( c) Small pole (m ~) commutation can be achieved by using. -~------~~-..;{'5111r~~~tl) • I (b) Compensating winding (c) High resistance carbon brushes <~ ~) c~ ~ ~ m> Page 2 of s, EDD013455BIC926233B5B41AFD679D8E , ( d) Large pole (qr~) ( d) None of these <~•lli)f~) 2020304 sbte.way2poly.in