CBSE Class 12 Electrical Technology Question Paper 2020

H$moS> Z§.
Code No. 343
amob Z§. narjmWu H$moS >H$mo CÎma-nwpñVH$m Ho$ _wI-n¥ð
Roll No. >na Adí` {bIo§ &
Candidates must write the Code on the
title page of the answer-book.

ZmoQ> NOTE
(I) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _o§ _w{ÐV (I) Please check that this question
n¥ð> 11 h¢ & paper contains 11 printed pages.

(II) àíZ-nÌ _| Xm{hZo hmW H$s Amoa {XE JE H$moS (II) Code number given on the right
>Zå~a H$mo N>mÌ CÎma-nwpñVH$m Ho$ _wI-n¥ð> na hand side of the question paper
{bI| & should be written on the title page of
the answer-book by the candidate.
(III) H¥$n`m Om±M H$a b| {H$ Bg àíZ-nÌ _| (III) Please check that this question
>42 àíZ h¢ & paper contains 42 questions.
(IV) H¥$n`m àíZ H$m CÎma {bIZm ewê$ H$aZo go (IV) Please write down the Serial
nhbo, CÎma-nwpñVH$m _| àíZ H$m H«$_m§H$ Number of the question in the
Adí` {bI| & answer-book before attempting it.
(V) Bg àíZ-nÌ H$mo n‹T>Zo Ho$ {bE 15 {_ZQ >H$m (V) 15 minute time has been allotted to
g_` {X`m J`m h¡ & àíZ-nÌ H$m {dVaU read this question paper. The
nydm©• _| 10.15 ~Oo {H$`m OmEJm & question paper will be distributed
10.15 ~Oo go 10.30 ~Oo VH$ N>mÌ Ho$db at 10.15 a.m. From 10.15 a.m. to
10.30 a.m., the students will read the
àíZ-nÌ H$mo n‹T>|Jo Am¡a Bg Ad{Y Ho$ Xm¡amZ question paper only and will not
do CÎma-nwpñVH$m na H$moB© CÎma Zht {bI|Jo & write any answer on the
answer-book during this period.

{dÚwV² àm¡Úmo{JH$s
ELECTRICAL TECHNOLOGY

{ZYm©[aV g_` : 3 KÊQ>o A{YH$V_ A§H$ : 60
Time allowed : 3 hours Maximum Marks : 60

.343 1 P.T.O.

gm_mÝ` {ZX}e :
(i) Bg àíZ-nÌ _| Xmo IÊS> h¢ & IÊS> H$ : amoOJma H$m¡eb Am¡a IÊS> I : {df` H$m¡eb &
(ii) IÊS> H$ : amoOJma H$m¡eb (10 A§H$)
 {XE JE 6 àíZm| _| go {H$Ýht 4 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 1 A§H$ H$m h¡ &
 {XE JE 5 àíZm| _| go {H$Ýht 3 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 2 A§H$ H$m h¡ &
(iii) IÊS> I : {df` H$m¡eb (50 A§H$)
 {XE JE 12 àíZm| _| go {H$Ýht 10 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 1 A§H$ H$m h¡ &
 {XE JE 7 àíZm| _| go {H$Ýht 5 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 2 A§H$ H$m h¡ &
 {XE JE 7 àíZm| _| go {H$Ýht 5 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 3 A§H$ H$m h¡ &
 {XE JE 5 àíZm| _| go {H$Ýht 3 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 5 A§H$ H$m h¡ &
(iv) Bg àíZ nÌ _| 42 àíZ em{_b h¢ {OZ_| go 30 àíZm| Ho$ CÎma XoZo h¢ &
(v) g^r àíZm| Ho$ {deof ^mJ/IÊS> H$mo ghr H«$_ _| H$s{OE &
(vi) A{YH$V_ g_` 3 K§Q>o h¡ &

IÊS> H$ : amoOJma H$m¡eb (10 A§H$)
{XE JE 6 àíZm| _| go {H$Ýht 4 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 1 A§H$ H$m h¡ & 14=4

1. _oar XmXr ao{S>`mo H$mo _________ ({h`a/{bgZ) H$aZm ng§X H$aVr h¢ & 1

2. {H$Ýht Xmo H$maH$m| H$mo Zm_ Xr{OE Omo h_mao ì`{ŠVËd H$mo AmH$ma XoVo h¢ & 1

3. g§JrV àoaUm H$m òmoV H¡$go h¡ ? 1

4. àXÿfU H$mo {Z`§{ÌV H$aZo Ho$ {bE h_| Š`m H$aZm Mm{hE ? 1

5. ‘{S>~oQ>’ eãX go Amn Š`m g_PVo h¢ ? 1

6. _oÝ`y ~ma AmonZAm°{\$g B§àog qdS>mo _| H$hm± pñWV h¡ ? 1

{XE JE 5 àíZm| _| go {H$Ýht 3 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 2 A§H$ H$m h¡ & 23=6
7. g{H«$` lmoVm ~ZZo Ho$ {bE Š`m {Q>ßg h¢ ? 2
8. àoaUm Ho$ òmoV Š`m h¢ ? 2
9. ^dZ {Z_m©U Ho$ joÌ _| Hw$N> h[aV Zm¡H$[a`m| H$s gyMr ~ZmBE & 2
10. EH$ N>mÌ {deof H$jm _| H¡$go {dH${gV hmoVm h¡ ? 2
11. Amn {H$gr àñVw{V gm°µâQ>do`a _| àñVw{V H¡$go ~§X H$a gH$Vo h¢ ? 2

.343 2

General Instructions :
(i) This question paper consists of two parts viz. Section A : Employability
Skills and Section B : Subject Skills.
(ii) Section A : Employability Skills (10 Marks)
 Answer any 4 questions out of the given 6 questions of 1 mark each.
 Answer any 3 questions out of the given 5 questions of 2 marks each.
(iii) Section B : Subject Skills (50 Marks)
 Answer any 10 questions out of the given 12 questions of 1 mark each.
 Answer any 5 questions from the given 7 questions of 2 marks each.
 Answer any 5 questions from the given 7 questions of 3 marks each.
 Answer any 3 questions from the given 5 questions of 5 marks each.
(iv) This question paper contains 42 questions out of which 30 questions are to
be answered.
(v) All questions of a particular part/section must be attempted in the correct
order.
(vi) The maximum time allowed is 3 hours.

SECTION A : Employability Skills (10 Marks)

Answer any 4 questions out of the given 6 questions of 1 mark each. 14=4
1. My grandmother likes to _________ (hear/listen) to the radio. 1
2. Name any two factors which shape our personality. 1
3. How is music a source of motivation ? 1
4. What should we do to control pollution ? 1
5. What do you understand by the term ‘Debate’ ? 1
6. Where is menu bar located in an Openoffice impress window ? 1

Answer any 3 questions out of the given 5 questions of 2 marks each. 23=6
7. What are the tips to become an active listener ? 2
8. What are the sources of motivation ? 2
9. List some green jobs in the field of building construction. 2
10. How does a student develop in a special class ? 2
11. How can you close a presentation in a presentation software ? 2

.343 3 P.T.O.

IÊS> I : {df` H$m¡eb (50 A§H$)

{XE JE 12 àíZm| _| go {H$Ýht 10 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 1 A§H$ H$m h¡ & 110=10

12. `{X pñWa bmoS> Q´>m§g\$m_©a na nmda \¡$ŠQ>a {nN>‹S> (níM hmo) OmVm h¡ V~ dh 1

(A) A{YH$ H$a§Q> boVm h¡
(B) H$_ H$a§Q> boVm h¡
(C) g_mZ H$a§Q>, H$_ nmda boVm h¡
(D) H$_ H$a§Q>, A{YH$ nmda boVm h¡

13. RLC g{H©$Q> _|, ao{µOñQ>|g, H$n¡{gQ>§g Am¡a B§S>ŠQ>¢g Ho$ g_mZm§Va dmoëQ>oO H«$_e… 80 dmoëQ>,
100 dmoëQ> Am¡a 160 dmoëQ> h¡ & g{H©$Q> H$m ewÕ dmoëQ>oO Š`m h¡ ? 1

(A) 80 V

(B) 100 V

(C) 140 V

(D) 340 V

14. bmoS> _| n[adV©Z Ho$ AZwgma {H$g àH$ma H$s hm{Z`m± hmoVr h¢ ? 1

(A) {hñQ>¡[a{gg
(B) ES>r
(C) H$m°na hm{Z`m±
(D) H$moa hm{Z`m±

15. Q´>m§g\$m_©a Ho$ ~«rXa _| à`wŠV Vab H$m Zm_ h¡ 1
(A) nmZr
(B) Z_H$
(C) I{ZO
(D) {g{bH$m Oob
.343 4

SECTION B : Subject Skills (50 Marks)

Answer any 10 questions out of the given 12 questions of 1 mark each. 110=10

12. If power factor lags on a static load transformer then it 1
(A) Takes more current
(B) Takes less current
(C) Takes same current, less power
(D) Takes less current, more power

13. In an RLC circuit, the parallel voltages across resistance, capacitance
and inductance are 80 volt, 100 volt and 160 volt respectively. What is
the net voltage of the circuit ? 1
(A) 80 V
(B) 100 V
(C) 140 V
(D) 340 V

14. Which types of losses occur according to change in load ? 1
(A) Hysteresis
(B) Eddy
(C) Copper loss
(D) Core loss

15. Name of liquid used in breather of a transformer is 1
(A) Water
(B) Salt
(C) Mineral
(D) Silica gel

.343 5 P.T.O.

16. DC grarO _moQ>a H$m J{V {Z`§ÌU H¡$go {H$`m OmEJm ? 1
(A) e§Q> \$sëS> aoJwboQ>a bJm H$a
(B) {S>dmBS>a Ûmam {Z`§{ÌV Zht H$a gH$Vo
(C) âbŠg KQ>mZo go
(D) Am_}Ma g{H©$Q> ao{µOñQ>|g ~‹T>mZo go

17. EH$ B§S>ŠeZ _moQ>a H$mo Mmby H$aZo na amoQ>a H$s Amd¥{Îm Š`m hmoJr ? 1

(A) 50 Hz
(B) gßbmB© \«$sŠd|gr Ho$ ~am~a
(C) pñbn \«$sŠd|gr Ho$ ~am~a
(D) 0

18. {ZåZ{b{IV _| go {H$g _moQ>a _| CÀM ñQ>m{Q>ªJ Q>m°H©$ hmoVm h¡ ? 1
(A) `y{Zdg©b _moQ>a
(B) H¡$no{gQ>a ñQ>mQ>© _moQ>a
(C) eoS>oS> nmob _moQ>a
(D) Cn`w©ŠV g^r

19. H$m¡Z-gm CnH$aU Ho$db DC Amny{V© na H$m_ H$aVm h¡ ? 1

(A) _yqdJ Am`aZ Q>mBn
(B) _yqdJ H$moBb Q>mBn
(C) na_mZ|Q> _¡JZoQ> Q>mBn
(D) Cn`w©ŠV g^r

20. {ZåZ{b{IV _| H$m¡Z-gm EH$ B§Q>rJ«oQ>oS> CnH$aU h¡ ? 1
(A) dmoëQ>_rQ>a
(B) dmQ>_rQ>a
(C) EZOu _rQ>a
(D) nmda \¡$ŠQ>a _rQ>a
.343 6

16. How will the speed control of a DC series motor be done ? 1
(A) Shunt field regulator
(B) Not with divider
(C) Reduction of flux
(D) Increase in armature resistance

17. What will be the rotor frequency when an induction motor is switched
on ? 1
(A) 50 Hz
(B) Equal to supply frequency
(C) Equal to slip frequency
(D) 0

18. Which of the following motors has a high starting torque ? 1
(A) Universal motor
(B) Capacitor start motor
(C) Shaded pole motor
(D) All of the above

19. Which instrument works only on DC supply ? 1
(A) Moving iron type
(B) Moving coil type
(C) Permanent magnet type
(D) All of the above

20. Which is an integrated instrument in the following ? 1
(A) Voltmeter
(B) Wattmeter
(C) Energy meter
(D) Power factor meter
.343 7 P.T.O.

21. ^mar CnH$aUm| H$mo g§^mbZo Ho$ {bE, {ZåZ{b{IV H$m Cn`moJ {H$`m OmVm h¡ : 1
(A) H«o$Z
(B) MoZ
(C) nwbr
(D) Cn`w©ŠV g^r

22. `{X Hy$ba H$s _moQ>a eyê$ Zht hmoVr h¡, Vmo BgH$m H$maU hmo gH$Vm h¡ : 1
(A) H$m°S>© _| Iwbm g{H©$Q>
(B) Amny{V© Zht
(C) _moQ>a dmB§qS>J _| Iwbm g{H©$Q>
(D) Cn`w©ŠV g^r

23. W_m}ñQ>oQ> {Z`§ÌU H$m Cn`moJ {H$`m OmVm h¡ : 1
(A) Q>o~b hrQ>a _|
(B) gmYmaU BbopŠQ´>H$ Am`aZ _|
(C) Am°Q>mo_¡{Q>H$ BbopŠQ´>H$ JrµOa _|
(D) Cn`w©ŠV g^r

{XE JE 7 àíZm| _| go {H$Ýht 5 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 2 A§H$ H$m h¡ & 25=10

24. AC g{H©$Q> _| nmda \¡$ŠQ>a Ho$ b¡qJJ Am¡a brqS>J go AmnH$m Š`m VmËn`© h¡ ? 2

25. Q´>m§g\$m_©a Š`m h¡ ? BgHo$ H$m`© {gÕm§V H$mo g§jon _| ñnîQ> H$s{OE & 2

26. {H$g pñW{V _|, Hw$N> Q´>m§g\$m_©a g_mZm§Va _| Omo‹S>o OmVo h¢ ? 2

27. {H$Ýht Mma AC qgJb \o$µO _moQ>am| H$m Zm_ {b{IE & 2

28. W_m}ñQ>¡Q> H$s H$m`©àUmbr Am¡a Cn`moJ {b{IE & 2

29. BbopŠQ´>H$ JrµOa _| hmoZo dmbo g§^m{dV Xmof Š`m h¢ ? 2

30. H¥${Ì_ ídgZ Ho$ {bE à`wŠV eoµ\$a H$s {d{Y H$m g§jon _| dU©Z H$s{OE & 2

.343 8

21. To handle heavy equipment, the following are used : 1
(A) Crane
(B) Chain
(C) Pulley
(D) All of the above

22. If the motor of a cooler fails to start, the cause may be : 1
(A) Open circuit in the cord
(B) No supply
(C) Open circuit in motor winding
(D) All of the above

23. Thermostat control is used in : 1
(A) Table heater
(B) Ordinary electric iron
(C) Automatic electric geyser
(D) All of the above

Answer any 5 questions from the given 7 questions of 2 marks each. 25=10

24. What do you mean by Lagging and Leading of power factor in an AC
Circuit ? 2

25. What is a Transformer ? Explain its working principle in brief. 2

26. In which condition are some transformers connected in parallel ? 2

27. Write the names of any four AC single phase motors. 2

28. Write the working and use of thermostat. 2

29. What are the possible faults which occur in an Electric Geyser ? 2

30. Describe in brief the Schafer’s method used for artificial respiration. 2

.343 9 P.T.O.

{XE JE 7 àíZm| _| go {H$Ýht 5 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 3 A§H$ H$m h¡ & 35=15
31. Q´>m§g\$m°_©a Ho$ gwajm Cnm`, gmdYm{Z`m| Am¡a AZwà`moJm| H$s ì`m»`m H$s{OE & 3
32. DC _moQ>a Ho$ {Z_m©U Am¡a H$m`©àUmbr H$s ì`m»`m H$s{OE & 3
33. W«r-\o$O AC _moQ>a ewê$ H$aZo Ho$ {bE EH$ ñQ>mQ>©a Š`m| Amdí`H$ h¡ ? g§jon _| g_PmBE & 3
34. AmaoI Ho$ gmW eo{S>S> nmob _moQ>a H$s H$m`©àUmbr H$s ì`m»`m H$s{OE & 3
35. AmaoI Ho$ gmW {S>{OQ>b Eå_oQ>a H$s ì`m»`m H$s{OE & 3
36. EH$ BbopŠQ´>H$ {_Šga Ho$ {Z_m©U Am¡a H$m`©àUmbr H$m dU©Z H$s{OE & 3
37. AmaoI Ho$ gmW EH$ ˜am~ B_e©Z am°S> H$s narjU à{H«$`m H$mo g_PmBE & 3

{XE JE 5 àíZm| _| go {H$Ýht 3 àíZm| Ho$ CÎma Xr{OE & àË`oH$ àíZ 5 A§H$ H$m h¡ & 53=15
38. AmaoI Ho$ gmW S>m`aoŠQ> Am°ZbmBZ _moQ>a ñQ>mQ>©a Ho$ {Z_m©U Am¡a H$m`©àUmbr H$s ì`m»`m
H$s{OE & 5
39. AmaoI Ho$ gmW qgJb-\o$O B§S>ŠeZ Q>mBn EZOu _rQ>a H$s H$m`©àUmbr H$s ì`m»`m
H$s{OE & 5
40. EH$ AmaoI H$s _XX go, ê$_ Hy$ba Ho$ {Z_m©U Am¡a H$m`©àUmbr H$s ì`m»`m H$s{OE & 5
41. {d{^Þ àH$ma H$s DC _moQ>g© Ho$ àH$ma Ed§ AZwà`moJ {b{IE & 5
42. EH$ AmaoI H$s _XX go, BbopŠQ´>H$ JrµOa Ho$ {Z_m©U Am¡a H$m`©àUmbr H$s ì`m»`m H$s{OE & 5

.343 10

Answer any 5 questions from the given 7 questions of 3 marks each. 35=15
31. Explain safety measures, precautions, and applications of transformer. 3
32. Explain the construction and working of a DC motor. 3
33. Why is a starter necessary to start a three-phase AC motor ? Explain
briefly. 3
34. With a diagram, explain the working of shaded pole motor. 3
35. With a diagram, explain Digital Ammeter. 3
36. Describe the construction and working of an Electric mixer. 3
37. Explain the testing process of a defective immersion rod with its diagram. 3

Answer any 3 questions from the given 5 questions of 5 marks each. 53=15
38. With a diagram explain the construction and working of a direct online
motor starter. 5
39. With a diagram explain the working of a single-phase induction type
energy meter. 5
40. With the help of a diagram, explain the construction and working of a
Room Cooler. 5
41. Write types and applications of different types of DC motors. 5
42. With the help of a diagram, explain the construction and working of an
Electric Geyser. 5

.343 11 P.T.O.