Questions & Answers · 2020. 9. 28. · 1 Questions & Answers for JEE (Advanced)-2020 Time : 3 hrs....
Transcript of Questions & Answers · 2020. 9. 28. · 1 Questions & Answers for JEE (Advanced)-2020 Time : 3 hrs....
1
Questions & Answersforforforforfor
JEE (Advanced)-2020
Time : 3 hrs. Max. Marks: 198
Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005
Ph.: 011-47623456 Fax : 011-47623472
PAPER - 2
DATE : 27/09/2020
PART - I : PHYSICS
[k.M[k.M[k.M[k.M[k.M - 1 (vf/dre vadvf/dre vadvf/dre vadvf/dre vadvf/dre vad : 18)
bl [k.M esa N% (06) ç'u gSaA
izR;sd iz'u dk mÙkj 0 ls 9 (nksuksa lfEfyr) rd dh ijkl esa ,dy vadh; iw.kk±d,dy vadh; iw.kk±d,dy vadh; iw.kk±d,dy vadh; iw.kk±d,dy vadh; iw.kk±d gS
çR;sd ç'u ds fy,] mÙkj ds lgh vkafdd eku dks ekÅl rFkk vkWu&LØhu opqZvy U;weSfjd dh–iSM ds mi;ksx ls mÙkj çfo"V
djus ds LFkku ij gh çfo"V dhft;sA
çR;sd ç'u ds mÙkj dk ewY;kadu uhps nh xbZ vadu ;kstuk ds vuqlkj fd;k tk;sxk:
iw.kZ vad : +3 ;fn dsoy lgh iw.kk±d eku dks çfo"V fd;k x;k gS_
'kwU; vad : 0 ;fn iz'u dk mÙkj ugha fn;k x;k gS
½.kkRed vad : –1 vU; lHkh fLFkfr;ksa esaA
1. iryh ikjn'khZ ÅèokZ/j nhokjksa okys rFkk ty
4
3vioruZ kad ls Hkjs gq, ,d cM+s oxkZdkj ik=k dks {kSfrt est ij j[kk tkrk
gSA ,d Nk=k blds fdlh ,d dksus ls 12 cm ij ,d irys lh/s rkj dks ty ds vUnj ÅèokZ/j :i ls j[krk gS] tSlk fdfp=k esa ;kstukc¼ :i ls fn[kk;k x;k gSA bl dksus ls rkj dks ns[krs gq,] vU; Nk=k rkj ds nks izfrfcEc ns[krk gS] tks n'kkZ,vuqlkj nf"V js[kk ds izR;sd Nksj ij lefer :i ls fLFkr gSA bu izfrfcEcksa ds eè; nwjh (cm esa) ____________ gSA
mÙkj (4)
JEE (ADVANCED)-2020 (Paper-2)
2
gygygygygy
12 ( , 0)0
S i
(x, y)
i
y
x
45°
izFke izfrfcEc S dk y funsZ'kkad 'y' gS
4 1 3sini sin45 sini
3 42
23
4 23
i i 32
= 45 – i
blfy, (–12, 0) ls xqtjus okyh js[kk dh <ky m = tan(45 – i) =
1 tani
1 tani gS
23 3
m23 3
lehdj.k
23 3 x 12 23 3y
23 3 23 3
vU; lehdj.k y = –x
vc
23 3 y 12 23 3y
23 3 23 3
12 23 32 23y
23 3 23 3
2y =
12 23 3
4.5 423
blfy,] nks izfrfcEcksa ds eè; nwjh 4 cm gSA
2. vuqizLFk&dkV {ks=kiQy St okyh ,d jsyxkM+h vuqizLFk&dkV {ks=kiQy S
0(S
0 = 4S
t) dh ,d yEch lqjax ds vUnj v
t pky ls
xfr'khy gSA ekuk dh jsyxkM+h ds lkeus yxHkx lHkh ok;q (?kuRo ) blds fljksa (fdukjksa) rFkk lqjax dh nhokjksa ds eè; ihNs
dh vksj izokfgr gksrh gSA rFkk] jsyxkM+h ds lkis{k ok;q izokg fLFkj rFkk iVyh; gSA ifjos'kh nkc ysrs gq, rFkk jsyxkM+h ds vUnj
ifjos'kh nkc p0 gSA ;fn jsyxkM+h ds fljksa rFkk lqjax dh nhokjksa ds eè; {ks=k esa nkc p gS] rc
2
0 t
7p p v
2N gSA N dk eku
________ gSA
mÙkj (9)
JEE (ADVANCED)-2020 (Paper-2)
3
gygygygygy jsyxkM+h ds lkis{k osx ysus ij
v
vt
4Stv
t = 3S
tv
t
4v v
3
blh izdkj ifjos'kh ok;q jsyxkM+h ds lkis{k vt pky ls xfr'khy gksxh
2 2
0 t t
1 1 16p v P v
2 2 9
2
0 t
1 7p p v
2 9
N = 9
3. 0.01 m dh nwjh }kjk iFkDÑr nks cM+h oÙkh; pdfr;ksa dks fp=k esa n'kkZ, vuqlkj ,d fLop }kjk ,d cSVjh ls la;ksftr fd;k
tkrk gSA ?kuRo 900 kg m–3 dh vkosf'kr rsy dh cw¡nksa dks 'kh"kZ pdrh ds dsUnz ij ,d efgu fNnz ls NksM+k tkrk gSA tc
dqN rsy dh cw¡nsa VfeZuy osx izkIr djrh gaS] rc pdfr;ksa ds fljksa ij 200 V dh oksYVrk vkjksfir djds fLop dks cUn fd;k
tkrk gSA ftlds ifj.kkeLo:i] f=kT;k 8 × 10–7 m dh rsy dh ,d cw¡n ÅèokZ/j :i ls xfr djuk cUn dj nsrh gS rFkk
pdfr;ksa ds eè; rSjrh gSA bl rsy dh cw¡n esa mifLFkr bysDVªkWuksa dh la[;k ________ gSA (mRIykou cy dks ux.; ekus]
xq:Roh; Roj.k = 10 ms–2 rFkk bysDVªkWu (e) ij vkos'k = 1.6 × 10–19 C ysa)
mÙkj (6)
gygygygygy
E 0.01 m
v 200E 100
l 1
JEE (ADVANCED)-2020 (Paper-2)
4
4E 2 10 v/m
mg
Eq
blh izdkj q = Ne (N, bysDVªkWuksa dh la[;k gS)
NeE = mg
NeE = 34r g
3
37
4 19
8 10 900 104N
3 2 10 1.6 10
N = 6
4. ,d gkWV ,;j cSywu dqN ;kf=k;ksa rFkk dqN jsr ds cLrs] ftuesa ls izR;sd dk nzO;eku 1 kg gS] bl izdkj ogu fd, gq, gSa
rkfd bldk dqy nzO;eku 480 kg gSA xqCckjs dks bldh mRIykodr iznku djus okyk bldk izHkkoh vk;ru V gSA xqCckjk
100 m dh lkE; Å¡pkbZ ij pyk;eku gSA tc N jsr ds cLrksa dks ckgj isaQdk tkrk gS] rc xqCckjk yxHkx 150 m dh uohu
lkE; Å¡pkbZ rd mB tkrk gS rFkk bldk vk;ru V vifjofrZr jgrk gSA ;fn /jkry ls Å¡pkbZ h ds lkFk ok;q ds ?kuRo dk
ifjorZu 0
h
h
0(h) eh
gS] tgk¡
0 = 1.25 kg m–3 rFkk h
0 = 6000 m, N dk eku _________ gSA
mÙkj (4)
gygygygygy ?kuRo dk ifjorZu (h) = 0h/h
0e
ekuk xqCckjs ds vUnj ok;q dk ?kuRo] ckg~; ok;q ds ?kuRo dh rqyuk esa ux.; gS] rc
480 g = Vg(100)
(480 – N)g = Vg(150)
480 (100)
480 N (150)
0
0
100
h
0
150
h
0
e480
480 N
e
0
50
h x480 50e e x
480 N 6000
480 501
480 N 6000
N 4
JEE (ADVANCED)-2020 (Paper-2)
5
5. m nzO;eku ds ,d fcUnq vkos'k q dks l yEckbZ dh ,d Mksjh }kjk ÅèokZ/j :i ls yVdk;k tkrk gSA vc f}/zqo vk?kw.kZ �
p ds
,d fcUnq f}/zqo dks vuUr ls q dh vksj bl izdkj yk;k tkrk gS fd vkos'k nwj xfr djrk gSA f}/zqo dh fn'kk] dks.kksa rFkk
nwfj;ksa lfgr fudk; dh vfUre lkE; fLFkfr uhps fp=k esa n'kkZ;h xbZ gSA ;fn f}/zqo dks bl fLFkfr rd ykus esa fd;k x;k dk;Z
N × (mgh) gS] tgk¡ g xq:Roh; Roj.k gS] rc N dk eku _________ gSA (è;ku nhft, dh fcUnq nzO;eku dks lkE;koLFkk esa
cuk, j[krs gq, rhu leryh; cyksa ds fy,, F
sin lHkh cyksa ds fy, leku gS] tgk¡ F dksbZ ,d cy gS rFkk vU; nks cyksa
ds eè; dks.k gS)
l
l
�
p
q h
2lsin
2
mÙkj (2)
gygygygygy
P mg90 –
2
Fd
90 – 2
T
Li"V :i ls d
Fmg T
sin 180sin 90 sin 90
2 2
blh izdkj d 3
0
q2pF Eq
4 2lsin2
izkjfEHkd fLFkfrt ÅtkZ = (0)
vfUre fLFkfrt ÅtkZ =
2
0
pqmgh W
4 2lsin2
blh izdkj 2
2lsin sin 2lsin h2 2 2
d
3
0
F mg 2pq mgsin
sincos cos4 2lsin2 22
JEE (ADVANCED)-2020 (Paper-2)
6
3
0
mg 2lsin sinpq 2
42 cos
2
3
2
mg 2lsin sin2
W mgh
2cos 2lsin2 2
mgsin 2lsin2W mgh
2cos2
mg 2sin cos lsin2 2 2W mgh
cos2
2W mg 2lsin mgh 2mgh2
N 2
6. 8 m Å¡pkbZz ds rkih; :i ls foyfxr csyukdkj cUn ik=k dks ÅèokZ/j :i ls j[kk x;k gSA bls 8.3 kg nzO;eku ds ,d
Å"ek&ik;Z (vkn'kZ rkih; pkyd) ?k"kZ.kghu foHkktd }kjk nks cjkcj Hkkxksa esa foHkkftr fd;k tkrk gSA vr% foHkktd izkjEHk esa
'kh"kZ ls 4 m dh nwjh ij fLFkr gS] tSlk fd uhps fp=k esa ;kstukc¼ :i ls fn[kk;k x;k gSA ik=k ds nksuksa Hkkxksa esa ls izR;sd
Hkkx esa 300 K rki ij ,d vkn'kZ xSl ds 0.1 eksy gSA vc foHkktd dks NksM+k tkrk gS rFkk ;g xSl dk fjlko gq, fcuk
ik=k ds ,d Hkkx ls nwljs Hkkx rd xfr djrk gSA tc lkE;koLFkk izkIr gksrh gS] rc 'kh"kZ ls foHkktd dh nwjh (m esa) _______
gksxh (xq:Roh; Roj.k = 10 ms–2 rFkk lkoZf=kd xSl fu;rkad = 8.3 J mol–1K–1 ysa).
8 m
mÙkj (6)
gygygygygy ekuk xSl vkn'kZ ,dy&ijek.kqd xSl gS
V
3C R
2
rFkk vuqizLFk dkV {ks=kiQy A gSA
izkjEHk esa
JEE (ADVANCED)-2020 (Paper-2)
7
0
P 4A 0.1R 300 (nksuksa ds fy,)
ekuk fiLVu x ehVj rd foLFkkfir gks tkrk gS rFkk vfUre rki T gSA
rc
2
P A(4 x) 0.1RT
2
0.1RT RTP A
4 x 10(4 x)P
1
P2
1 x
rFkk 1
RTP A
10(4 x)
ysfdu vUr esa 2 1
RT 1 1P A P A 83
10 4 x 4 x
2
RT 2x83
10 16 x
V V
0.2 C 300 mg x 0.2C T
3 2 2 3R 300 83x RT
2 10 10 2
900R RT83x 3
10 10
300R 83 RTx
10 3 10
2
83x 2x30R 83
3 16 x
2
x 2x83 3 83
3 16 x
2
(9 x) (2x)1
3 16 x
18x + 2x2 = 48 – 3x2
5x2 + 18x – 48 = 0
x 1.78 2
blfy,] 'kh"kZ ls nwjh 6 m gSA
JEE (ADVANCED)-2020 (Paper-2)
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[k.M[k.M[k.M[k.M[k.M - 2 (vf/dre vadvf/dre vadvf/dre vadvf/dre vadvf/dre vad : 24)
bl [k.M esa N% (06) ç'u gSaA
çR;sd ç'u ds pkjpkjpkjpkjpkj fodYi gSaA bu pkj fodYiksa eas ls ,d ;k ,d ls vf/d,d ;k ,d ls vf/d,d ;k ,d ls vf/d,d ;k ,d ls vf/d,d ;k ,d ls vf/d lgh mÙkj gS@gSaA
çR;sd ç'u ds fy, (lHkh) lgh mÙkjksa ls lacaf/r fodYi@fodYiksa dk p;u dhft;sA
çR;sd ç'u ds mÙkj dk ewY;kadu uhps nh xbZ vadu ;kstuk ds vuqlkj fd;k tk,xk:
iw.kZ vad : +4 ;fn dsoy lHkh lgh fodYi@fodYiksa dk p;u fd;k x;k gS_
vakf'kd vad : +3 ;fn lHkh pkj fodYi lgh gSa ijUrq dsoy rhu fodYiksa dk p;u fd;k x;k gS_
vakf'kd vad : +2 ;fn rhu ;k vf/d fodYi lgh gSa ijUrq dsoy nks fodYiksa dk p;u fd;k x;k gS rFkk nksuksa lgh
gks_
vkaf'kd vad : +1 ;fn nks ;k vf/d fodYi lgh gSa ijUrq dsoy ,d fodYi dk p;u fd;k x;k gS rFkk og lgh
fodYi gks_
'kwU; vad : 0 ;fn fdlh Hkh fodYi dk p;u ugha fd;k x;k gSA (vFkkZr~ ç'u dk mÙkj ugha fn;k x;k gks);
½.kkRed vad : –2 lHkh vU; fLFkfr;ksa esaA
7. r f=kT;k ds ,d chdj dks ty viorZukda 4
3
ls H Å¡pkbZ rd Hkjk tkrk gS] tSlk fd ck;ha vksj fp=k esa fn[kk;k x;k gSA
chdj dks dks.kh; pky ls ?kwf.kZr ,d {kSfrt est ij j[kk tkrk gSA ;g ty dh lrg dks bl izdkj oØkdkj cukrk gS fd
chdj ds dsUnz ij ty dh Lrj dh Å¡pkbZz rFkk bldh ifjf/ ij ty ds Lrj dh Å¡pkbZ esa vUrj h (h << H,
h << r) gS] tSlk fd nk;ha vksj fp=k esa fn[kk;k x;k gSA bl lrg dks yxHkx xksyh; ys] ftldh oØrk f=kT;k R gSA fuEu esa
ls dkSulk@dkSuls lgh gS@gSa\ (g, xq:Roh; Roj.k gS)
H
h
(A)
2 2h r
R2h
(B) 2
3rR
2h
(C) chdj ds iSans dh vkHkklh xgjkbZ yxHkx
123H H
12 2g
gS
(D) chdj ds iSans dh vkHkklh xgjkbZ yxHkx
123H H
14 4g
gS
mÙkj (A, D)
JEE (ADVANCED)-2020 (Paper-2)
9
gygygygygy2
2h r2g
R2 = r2 + (R – h)2
2 2
2
r h g hR
2h 2
r
R (R – h)
H
oØkdkj lrg ds viorZu ds fy, lw=k iz;qDr djus ij
4 41
1 3 3
v H R
1 4 1
v 3H 3R
3HRv
4R H
vkHkklh xgjkbZ =
13H H
| v | 14 4R
=
123H H
14 4g
8. ,d Nk=k ,d jsEi ds Åij dh vksj LdsfVax djrk gS] tks {kSfrt ds lkFk 30° dks.k cukrk gSA og v0 pky ls jsEi ds vk/kj
ls izkjEHk (tSlk dh fp=k esa fn[kk;k x;k gS) gksrk@gksrh gS rFkk R f=kT;k ds ,d v¼ZoÙkh; iFk xyz ds Åij ?kweuk pkgrk@pkgrh
gS ftlds nkSjku og /jkry ls vf/dre Å¡pkbZ h (fcUnq y ij) igq¡prk@igq¡prh gS tSlk fd fp=k esa fn[kk;k x;k gSA ekuk fd
ÅtkZ gkfu ux.; gS rFkk mPpre fcUnq ij bl ?kqeko ds fy, vko';d cy dsoy mlds Hkkj }kjk iznku fd;k tkrk gSA rc
(g xq:Roh; Roj.k gS)
Rz
y
x
30°
h
(A) 2
0
1v 2gh gR
2
(B) 2
0
3v 2gh gR
2
(C) fcUnq x rFkk z ij vko';d vfHkdsUnzh; cy 'kwU; gS
(D) vko';d vfHkdsUnzh; cy fcUnq x rFkk z ij vf/dre gS
mÙkj (A, D)
JEE (ADVANCED)-2020 (Paper-2)
10
gygygygygy fcUnq y ij
mg sing30° =
2mv
R
2 gRv
2
y
mg sin 30°xz
;kaf=kd ÅtkZ laj{k.k iz;qDr djus ij
2 2
0
1 1mv mgh mv
2 2
2
0
gRv 2gh
2
iFk xyz ds vuqfn'k] pky fcUnq x RkFkk z ij vf/dre gS] blfy, vf/dre vfHkdsUnzh; cy dh vko';drk gksxhA
9. nzO;eku m rFkk yEckbZ L dh ,d NM+] tks vius fdlh ,d fljs ij dhyfdr gS] ÅèokZ/j :i ls yVdk;h xbZ gSA v pky ls
xfr'khy leku nzO;eku dh ,d xksyh NM+ ls blds dhyfdr fljs ls x nwjh ij Vdjkrh gS rFkk blesa /¡l tkrh gSA vc la;qDr
fudk; dhyd ds lkis{k dks.kh; pky ls ?kw.kZu djrk gSA vf/dre dks.kh; pky M
, x = xM ds fy, izkIr gksrh gSA rc
L
x
v
(A) 2 2
3vx
L 3x(B)
2 2
12vx
L 12x
(C) M
Lx
3(D)
M
v3
2L
mÙkj (A, C, D)
gygygygygy dhyd ds lkis{k dks.kh; laosx laj{k.k iz;qDr djus ij
L, m
x
m
v
2
2 mLmvx mx
3
2 2
3vx
L 3x
M
d L0 x
dx 3
rFkk M
3v
2L
JEE (ADVANCED)-2020 (Paper-2)
11
10. ,d X-fdj.k uyh esa] /kjk I xzg.k fd, gq, ,d rUrq (dSFkksM+) ls mRlftZr bysDVªkWu dSFkksM+ ls d nwjh ij ,d y{; (,uksM) lsVdjkrs gSaA y{; dks dSFkksM+ ls mPp foHko V ij j[kk tkrk gS ftlds ifj.kkeLo:i lrr~ rFkk vfHkyk{kf.kd X-fdj.kksa dk
mRltZu gksrk gSA ;fn rUrq dh /kjk I dks I
2 rd ?kVk;k tkrk gS] rc foHkokUrj V, 2V rd c<+ tkrk gS rFkk iFkDdj.k nwjh
d, d
2 rd ?kV tkrh gS] rc
(A) vard rjaxnSè;Z vk/s rd ?kV tk,xh rFkk vfHkyk{kf.kd X-fdj.kksa dh rjaxnSè;Z leku jgsxh
(B) vard rjaxnSè;Z rFkk vfHkyk{kf.kd X-fdj.kksa dh rjaxnSè;Z leku jgsxh
(C) vard rjaxnSè;Z vk/s rd ?kV tk,xh rFkk lHkh X-fdj.kksa dh rhozrk,sa ?kVsxh
(D) vard rjaxnSè;Z nks xquk vf/d gks tk,xh rFkk lHkh X-fdj.kksa dh rhozrk,sa ?kVsxh
mÙkj (A, C)
gygygygygy tc vkifrr bysDVªkWuksa dh ÅtkZ dks nksxquk fd;k tkrk gS] rc vard rjaxnSè;Z vk/s rd ?kV tk,xhA vfHkyk{kf.kd X-fdj.kdh rjaxnSè;Z izHkkfor ugha gksxhA rUrq dh /kjk esa deh ds dkj.k rhozrk ?kVsxhA
11. leku nzO;eku rFkk vkos'k ds nks ,dleku vpkyd Bksl xksyksa dks leku yEckbZ dh nks vpkyd] nzO;ekughu Mksfj;ksa }kjk ,d
mHk;fu"B fcUnq ls ok;q esa yVdk;k tkrk gSA lkE;koLFkk ij] Mksfj;ksa ds eè; dks.k gSA vc xksyksa dks 800 kg m–3 ?kuRo rFkk
ijkoS|qrkad 21 ds ,d ijkoS|qr nzo esa Mqck;k tkrk gSA ;fn Mqckus ds ckn Mksfj;ksa ds eè; dks.k leku jgrk gS] rc
(A) xksyksa ds eè; fo|qr cy vifjofrZr jgrk gS
(B) xksyksa ds eè; fo|qr cy ?kVrk gS
(C) xksyksa dk nzO;eku ?kuRo 840 kg m–3 gS
(D) xksyksa dks lEHkkyus okyh Mksfj;ksa esa ruko vifjofrZr jgrk gS
mÙkj (A, C)
gygygygygy xksys ij usV cy ?kVsxk] ysfdu xksyksa ds eè; cy leku jgsxkA
tc ok;q esa
mg
TFe
eF
tan2 mg
rFkk 2 2
eT F (mg)
tc nzo esa Mqck;k tkrk gS
rFkke
2
2e
FFktan T (mg B)
2 mg B k
b
mg kmg 1
�
b
k 21 800
k 1 21 1
�
= 840 kg/m3
JEE (ADVANCED)-2020 (Paper-2)
12
12. 1 ms–1 dh pky ls ewy fcUnq ls le; t = 0 ij izkjEHk gksus okyk] ,d d.k x-y ry esa nks&foeh; iz{ksi&iFk dk bl izdkj
vuqlj.k djrk gS fd blds funsZ'kkad lehdj.k 2x
y2
}kjk lEcfU/r gksrs gSaA blds Roj.k ds x rFkk y ?kVdksa dks Øe'k%
ax rFkk a
y }kjk iznf'kZr fd;k tkrk gSA rc
(A) ax = 1 ms–2 n'kkZrk gS fd tc d.k ewy fcUnq ij gS] rc a
y = 1 ms–2
(B) ax = 0 n'kkZrk gS fd lHkh le; ij a
y = 1 ms–2
(C) t = 0 ij] d.k dk osx x-fn'kk esa bafxr djrk gS
(D) ax = 0 n'kkZrk gS fd t = 1 s ij] d.k ds osx rFkk x v{k ds eè; dks.k 45° gS
mÙkj (A, B, C, D)
gygygygygy2x
y2
dy dxx
dt dt
2xy
2
22 2
2 2
d y d x dxx
dtdt dt
t = 0 ij, x = 0 vx = 1 m/s rFkk v
y = 0 m/s
x = 0 ij ax = 1 ds fy,
ay = 1 m/s2
ax = 0 ds fy,
x ds lHkh ekuksa ds fy, ay = 1 m/s2
t = 1 s ij ax = 0 ds fy,
x yˆ ˆv v i v j
�
ˆ ˆ1i 1j
[k.M[k.M[k.M[k.M[k.M - 3 (vf/dre vadvf/dre vadvf/dre vadvf/dre vadvf/dre vad : 24)
bl [k.M esa N% (06) ç'u gSaA çR;sd ç'u dk mÙkj ,d vkafdd eku gSA
çR;sd ç'u ds fy,] mÙkj ds lgh vkafdd eku dks ekÅl rFkk vkWu&LØhu opqZvy U;weSfjd dh–iSM ds mi;ksx ls mÙkj çfo"V
djus ds LFkku ij gh çfo"V dhft;sA ;fn vakfdd eku esa nks ls vf/d n'keyo LFkku gks] rks çkIr eku dk nks n'keyo LFkku rd
lfUudVu djsaA
çR;sd ç'u ds mÙkj dk ewY;kadu uhps nh xbZ vadu ;kstuk ds vuqlkj fd;k tk;sxk:
iw.kZ vad : +4 ;fn dsoy lgh vakfdd eku dks çfo"V fd;k x;k gS_
'kwU; vad : 0 vU; lHkh fLFkfr;ksa esaA
JEE (ADVANCED)-2020 (Paper-2)
13
13. ty ds vUnj ,d xksyh; cqycqys dh f=kT;k R gSA cqycqys ds vUnj nkc rFkk ty dk nkc p0 ds :i esa ysaA vc cqycqyk
:¼ks"e izdkj ls vjh; :i ls bl izdkj lEihfM+r gks tkrk gS fd bldh f=kT;k (R – a) gks tk,A a << R ds fy,] izfØ;k esa
fd, x, dk;Z ds ifjek.k dks (4p0Ra2)X }kjk O;Dr fd;k tkrk gS] tgk¡ X ,d fu;rkad gS rFkk = C
p/C
v = 41/30 gSA
X dk eku ________ gSA
mÙkj (1.00)
gygygygygy fd;k x;k dk;Z = IE esa of¼ = Uf – U
i =
0 0PV P V
1...(i)
blh izdkj 0 0
P V PV
0
0
VP P
V...(ii)
(i) rFkk (ii) ls
010 0 0
0
0 0
VP V P V
V30W P V 1
1 11
3( 1)
0 0 0 0 3( 1)
30 R 30 1W P V 1 P V 1
11 R a 11 a1
R
3(1 )
0 0 0 0
30 a 30 aP V 1 1 P V 1 3(1 ) 1
11 R 11 R
3
0
30 4 11 aW P R 3
11 3 30 R
2 2
0 0W (4 R P a)x (4 R P )a x 01
14. lUrqyu dh fLFkfr esa] ,d OghVLVksu lsrq dh pkj Hkqtkvksa ds izfrjks/ksa ds eku uhps fp=k esa n'kkZ,s x, gSA izfrjks/ R3 dk rki
xq.kkad 0.0004 ºC–1 gSA ;fn R3 ds rki dks 100 ºC rd c<+k;k tkrk gS] rc S rFkk T ds eè; mRiUu oksYVrk __________
oksYV gksxhA
V
P
Q
TS
R = 60 1
R = 100 2
R = 500 4
R = 300 3
50
V
mÙkj (0.27)
JEE (ADVANCED)-2020 (Paper-2)
14
gygygygygy 4 2 2
3 3 3 3R R [1 E) R [1 4 10 10 ) R [1 4 10 ]
3
R 300[1 0.04] 300 1.04 3 104 312
1
50I A
372
P S 1
50V V I 60 60
372
500
60 100
312 = R3
I1 I
2
TS
P
50 V
okYs VP S
500V V
62
2
50 50 5I A
100 500 600 60
oksYVP T
5 50V V 100
60 6
P T P S S T
50 500 500 500(V V ) (V V ) V V
6 62 60 62
S T
1 1 2 1000 100V V 500 500
60 62 60 62 60 62 6 62 okYs V100
0.2688372
okYs VS T
V V 0.27
15. /kfjrk eku C1 = 2000 10 pF rFkk C
2 = 3000 15 pF okys nks la/kfj=kksa dks Js.khØe esa la;ksftr fd;k tkrk gSA bl
la;kstu ds fljksa ij vkjksfir oksYVrk V = 5.00 0.02 V gSA la/kfj=kksa ds bl la;kstu esa laxzfgr ÅtkZ dh x.kuk esa izfr'kr
=kqfV _______ gSA
mÙkj (1.30)
gygygygygy
1 2
1 2
C C 2000 3000 6000C pf
C C 5000 5
1 2
2 2 21 2 1 2
C C1 1 1 C
C C C C C C
2 1 2
2 2
1 2
C C 9 4C C 10 15 6nF
25 25C C
22
2 2
1
C 6000 1 9
5 25C (2000)
JEE (ADVANCED)-2020 (Paper-2)
15
2 22
2
2
C 6000 1 4
5 3000 25C
21 U C 2 VU CV 100 100 100
2 U C V
U 6 5 0.02
100 100 2 100U 6000 5
= 0.5 + 0.8 = 1.30
16. iFoh dh lrg ij ,d ?kuh; Bksl ,yqfefu;e (vk;ru izR;kLFkrk xq.kkad = dP
VdV
= 70 GPa) ds ,d xqVds dh Hkqtk dh
yEckbZ 1 m gSA bls 5 km xgjs egklkxj dh ryh ij j[kk tkrk gSA ty dk vkSlr ?kuRo rFkk xq:Roh; Roj.k Øe'k%
103 kg m–3 rFkk 10 ms–2 ysus ij] xqVds dh Hkqtk dh yEckbZ esa ifjorZu (mm esa) _____ gSA
mÙkj (0.24)
gygygygygy dPV BdV
dV dP
V B
3( dl) dP
l B
3 34
9
l dP l gh 1 10 10 5 10l 2.4 10 0.24 mm
3 B 3 B 3 70 10
17. nks LR ifjiFkksa ds izsjdksa dks ,d nwljs ds lehi j[kk tkrk gS] tSlk fd fp=k esa fn[kk;k x;k gSA izsjdksa ds Lo&izsjdRo] izfrjks/]
vU;ksU;&izsjdRo rFkk vkjksfir oksYVrkvksa ds eku fn, x, ifjiFk esa iznf'kZr gSaA nksuksa fLopksa dks ,d lkFk cUn djus ds ckn]
/kjkvksa ds vius LFkk;h voLFkk eku izkIr djus ds le; rd izsjdksa esa izsfjr fo-ok-c- ds fo:¼ cSVfj;ksa }kjk fd;k x;k dqy dk;Z
________ mJ gSA
V =
5 V
1 L =
10
mH
1
R = 5 1
I1
M =
5 m
H
R = 10 2
I2
V =
20
V2L
= 2
0 m
H2
mÙkj (55)
JEE (ADVANCED)-2020 (Paper-2)
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gygygygygy 1
5I 1 A
5
2
20I 2 A
10
izsfjr fo-ok-c- ds fo:¼ cSVjh }kjk fd;k x;k dqy dk;Z = pqEcdh; ÅtkZ esa of¼
= U1 + U
2 + U
12
2 2
1 1 2 2 1 2
1 1W L I L I MI I
2 2
3 2 2 3 31 110 10 1 20 (2) 10 5 10 1 2
2 2
3(5 40 10) 10
= 55 mJ
18. ,d ik=k esa 1 kg ty Hkjk gqvk gS] bls lw;Z ds izdk'k esa j[kk tkrk gS] ftlds dkj.k ty ifjos'k dh rqyuk esa xeZ gks tkrk
gSA lw;Z ds izdk'k ds dkj.k izkIr dh xbZ izfr bdkbZ {ks=kiQy izfr bdkbZ le; vkSlr ÅtkZ 700 Wm–2 gS rFkk bls
0.05 m2 ds izHkkoh {ks=kiQy ij ty }kjk vo'kksf"kr fd;k tkrk gSA ekuk fd ty ls ifjos'k dh vksj Å"ek gkfu U;wVu ds
'khryu ds fu;e }kjk lapkfyr gksrh gS] yEcs le; ds ckn ty rFkk ifjos'k ds rki esa vUrj (ºC esa) _____________ gksxkA
(ik=k ds izHkko dks ux.; ekusa rFkk U;wVu ds 'khryu ds fu;e ds fy, fu;rkad = 0.001 s–1 ysa] ty dh Å"ek /kfjrk
= 4200 J kg–1 K–1)
mÙkj (8.33)
gygygygygy lkE;koLFkk esa
izfr lsd.M izkIr dh xbZ Å"ek = izfr lsd.M Å"ek gkfu
E × A = S
0K ms[ ] M
( – 0) =
3
E A 700 0.05 ºC
K S M 10 4200 1
=
2
3 2
700 5 10 35 350 508.33ºC
4.2 42 610 42 10
JEE (ADVANCED)-2020 (Paper-2)
17
PART-II : CHEMISTRY
[k.M[k.M[k.M[k.M[k.M - 1 (vf/dre vadvf/dre vadvf/dre vadvf/dre vadvf/dre vad : 18)
bl [k.M esa N% (06) ç'u gSaA
izR;sd iz'u dk mÙkj 0 ls 9 (nksuksa lfEfyr) rd dh ijkl esa ,dy vadh; iw.kk±d,dy vadh; iw.kk±d,dy vadh; iw.kk±d,dy vadh; iw.kk±d,dy vadh; iw.kk±d gS
çR;sd ç'u ds fy,] mÙkj ds lgh vkafdd eku dks ekÅl rFkk vkWu&LØhu opqZvy U;weSfjd dh–iSM ds mi;ksx ls mÙkj çfo"V
djus ds LFkku ij gh çfo"V dhft;sA
çR;sd ç'u ds mÙkj dk ewY;kadu uhps nh xbZ vadu ;kstuk ds vuqlkj fd;k tk;sxk:
iw.kZ vad : +3 ;fn dsoy lgh iw.kk±d eku dks çfo"V fd;k x;k gS_
'kwU; vad : 0 ;fn iz'u dk mÙkj ugha fn;k x;k gS
½.kkRed vad : –1 vU; lHkh fLFkfr;ksa esaA
1. ijek.kq Øekad n, n + 1, n + 2 rFkk n + 3 tgk¡ n < 10, okys pkj ijek.kqvksa dh 1st, 2nd, rFkk 3rd vk;uu ,UFkSYih I1, I
2, rFkk
I3] uhps lkj.kh esa nh x;h gSA n dk eku D;k gS\
ijek.kqØekad
vk;uu ,UFkSYih (kJ/mol)
I1
I2 I
3
n
n + 1
n + 2
n + 3
1681
2081
738
496
3374
1451
3952
4562
6050
6910
6122
7733
mÙkj (9)
gy %gy %gy %gy %gy % n = 9 (Ýyqvksjhu)
n + 1 = 10 (Ne)
n + 2 = 11 (Na)
n + 3 = 12 (Mg)
2. nzzo :i esa fuEufyf[kr ;kSfxdksa ij fopkj dhft,: O2, HF, H
2O, NH
3, H
2O
2, CCl
4, CHCl
3, C
6H
6, C
6H
5Cl.
tc ,d vkosf'kr daèks dks budh fuEufyf[kr èkkjk ds lehi yk;k tkrk gS] rks buesa ls fdrus fuEufyf[kr fp=k ds vuqlkjfopyu n'kkZrs gSa\
mÙkj (7)
gy %gy %gy %gy %gy % vuqpqEcdh; nzo rFkk èkzqoh; nzo vkosf'kr da?ks dh vksj vkdf"kZr gksaxsA vr% fopyu n'kkZus okys nzo O2, HF, H
2O, NH
3,
H2O
2, CHCl
3, C
6H
5Cl gSa
JEE (ADVANCED)-2020 (Paper-2)
18
3. nqcZy {kkjh; foy;u esa KMnO4 rFkk KI dh jllehdj.kferh; fHkrh; ek=kkvksa ds eè; jklk;fud vfHkfØ;k esa 4 eksy KMnO
4
iz;qDr gksus ds fy, eqDr I2 ds eksyksa dh la[;k D;k gS\
mÙkj (0)
gy %gy %gy %gy %gy % 4 2 2 3
2MnO H O I 2MnO 2OH IO
4. iksVSf'k;e ØksesV ds vEyhdr foy;u dks ,fey ,YdksgkWy ds leku vk;ru ds lkFk feyk;k tkrk gSA tc bls 1 mL, 3%
H2O
2 foy;u feykus ds ckn foyksfMr fd;k tkrk gS rks uhys ,YdksgkWy dh ijr izkIr gksrh gSA uhyk jax Øksfe;e (VI) ;kSfxd
‘X’ ds cuus ds dkj.k gksrk gSA X ds ,d v.kq eas Øksfe;e ds lkFk dsoy ,dy cUèk }kjk cfUèkr vkWDlhtu ijek.kqvksa dhla[;k D;k gS\
mÙkj (4)
gy %gy %gy %gy %gy % 2
4 2 2 5 2CrO 2H 2H O CrO 3H O
X, CrO5 gSA
Cr
O
O
O
O
O
dsoy ,dy ca/ }kjk Øksfe;e ls caf/r vkWDlhtu ijek.kqvksa dh la[;k 4 gSA
uhyk jax Øksfe;e isUVkvkWDlkbM dh mifLFkfr ds dkj.k gksrk gSA
5. uhps ,d isIVkbM dh lajpuk nh x;h gS
HO
H N2
O
H
NN
H
O
OH
O
CO H2
NH2
;fn pH = 2, pH = 6, rFkk pH = 11 ij isIVkbM ij usV vkos'k ds fujis'k eku Øe'k% |z1|, |z
2|, rFkk |z
3| gSa] rks |z
1| + |z
2|
+ |z3| dk eku D;k gS\
mÙkj (5)
gy %gy %gy %gy %gy % pH = 2 ij
|Z1| = 2 (lHkh ,ehuks vERy
3NH ds :i esa ik, tkrs gSa)
pH = 6 ij
|Z2| = 0 (TohVj vk;u :i)
pH = 11 ij
|Z3| = |–3| = 3 (lHkh COOH o OH, –COO o –O ds :i esa ik, tkrs gSa)
|Z1| + |Z
2| + |Z
3| = 2 + 0 + 3 = 5
6. ,d dkcZfud ;kSfxd (C8H
10O
2) lery èkzqfor izdk'k dks ?kwf.kZr dj nsrk gSA ;g mnklhu FeCl
3 foy;u ds lkFk xqykch jax
nsrk gSA bl ;kSfxd ds fy, lHkh laHko leko;fo;ksa dh dqy la[;k D;k gS\
mÙkj (6)
JEE (ADVANCED)-2020 (Paper-2)
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gy %gy %gy %gy %gy %
OH
C* — CH3
OH
H
OH
C* — CH3
OH
HOH
HC* — CH3
OH
iQhuksfyd lewg mnklhu FeCl3 ds lkFk /ukRed ijh{k.k nsrk gSA
[k.M[k.M[k.M[k.M[k.M - 2 (vf/dre vadvf/dre vadvf/dre vadvf/dre vadvf/dre vad : 24)
bl [k.M esa N% (06) ç'u gSaA
çR;sd ç'u ds pkjpkjpkjpkjpkj fodYi gSaA bu pkj fodYiksa eas ls ,d ;k ,d ls vf/d,d ;k ,d ls vf/d,d ;k ,d ls vf/d,d ;k ,d ls vf/d,d ;k ,d ls vf/d lgh mÙkj gS@gSaA
çR;sd ç'u ds fy, (lHkh) lgh mÙkjksa ls lacaf/r fodYi@fodYiksa dk p;u dhft;sA
çR;sd ç'u ds mÙkj dk ewY;kadu uhps nh xbZ vadu ;kstuk ds vuqlkj fd;k tk,xk:
iw.kZ vad : +4 ;fn dsoy lHkh lgh fodYi@fodYiksa dk p;u fd;k x;k gS_
vakf'kd vad : +3 ;fn lHkh pkj fodYi lgh gSa ijUrq dsoy rhu fodYiksa dk p;u fd;k x;k gS_
vakf'kd vad : +2 ;fn rhu ;k vf/d fodYi lgh gSa ijUrq dsoy nks fodYiksa dk p;u fd;k x;k gS rFkk nksuksa lghgks_
vkaf'kd vad : +1 ;fn nks ;k vf/d fodYi lgh gSa ijUrq dsoy ,d fodYi dk p;u fd;k x;k gS rFkk og lghfodYi gks_
'kwU; vad : 0 ;fn fdlh Hkh fodYi dk p;u ugha fd;k x;k gSA (vFkkZr~ ç'u dk mÙkj ugha fn;k x;k gks);
½.kkRed vad : –2 lHkh vU; fLFkfr;ksa esaA
7. ,d iz;ksx eas ,d ik=k esa fy, x, m xzke ;kSfxd X (xSl/nzo/Bksl) dks uhps fp=k I esa n'kkZ, vuqlkj ,d rqyk ij j[kk tkrk gSApqEcdh; {ks=k dh mifLFkfr esa X okyk iyM+k ;kSfxd X ij fuHkZjrk ds vkèkkj ij ;k rks Åij dh (fp=k II) ;k uhps dh vksj(fp=k III) fopfyr gksrk gSA lgh dFku@dFkuksa dks igpkfu;sA
pqEcd
Nm x
S SN
(I)
larqfyrpqEcdh;
{ks=k vuqifLFkr
(II)
Åij dh vksjfopyu pqEcdh;{ks=k mifLFkr
(III)
uhps dh vksjfopyu pqEcdh;{ks=k mifLFkr
(A) ;fn X, H2O(l) gks rks iyMs+ dk fopyu Åij dh vksj gksxk
(B) ;fn X, K4[Fe(CN)
6](s), gks rks iyMs+ dk fopyu Åij dh vksj gksxk
(C) ;fn X, O2 (g) gks rks iyMs+ dk fopyu uhps dh vksj gksxk
(D) ;fn X, C6H
6(l) gks rks iyMs+ dk fopyu uhps dh vksj gksxk
mÙkj (A,B,C)
JEE (ADVANCED)-2020 (Paper-2)
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gy gy gy gy gy : H2O(l), K
4[Fe(CN)
6](s) ,oa C
6H
6(l) çfrpqEcdh; ;kSfxd gSA ;s ;kSfxd pqEcdh; {ks=k ls Åij dh vksj fopfyr gksxs
O2(g) vuqpqEcdh; gS ;g pqEcdh; {ks=k dh vksj (uhps dh vksj) vkd£"kr gksxhA
8. nh x;h vfHkfØ;k ds fy, fuEu esa ls dkSuls vkjs[k lgh gS@gSa\
(P dh izkjfEHkd lkanzrk [P]0 gS ) H C
3Br
CH3
CH3
+ NaOH H C3
OH
CH3
CH3
+ NaBr
P Q
(A)
[P]0
t1/2
(B)
[P]0
izkjfE
Hkd o
sx
(C)
le;
0
[Q]
[P]
(D)
le;
0
[P]ln
[P]
mÙkj (A)
gy gy gy gy gy : osx [fØ;k/kj]1 (SN
1 vfHkfØ;k ds fy,)
osx = k[[P]0 – X]
vfHkfØ;k dh dksfV = 1
izFke dksfV vfHkfØ;k ds fy, Q = [P]0(1 – e–kt)
t1/2
izkjfEHkd lkanzrk ij fuHkZj ugha djrkA
JEE (ADVANCED)-2020 (Paper-2)
21
9. ckWDlkbV ls ,yqfefu;e ds fu"d"kZ.k ds fy, fuEu esa ls dkSulk@dkSuls dFku gS@gSa\
(A) tc lksfM;e ,yqfeusV ds foy;u esa CO2 izokfgr dh tkrh gS] rks ty;ksftr Al
2O
3 vo{ksfir gksrk gS
(B) Na3AlF
6 feykus ij ,yqfeuk dk xyukad de gks tkrk gS
(C) fo|qr vi?kVu ds nkSjku ,uksM ij CO2 eqDr gksrh gS
(D) dSFkksM ,d LVhy dk ik=k gksrk gS ftlesa dkcZu dk vLrj yxk gksrk gS
mÙkj (A,B,C,D)
gy gy gy gy gy : Al2O
3 + 2NaOH + 3H
2O 2Na[Al(OH)
4]
2Na[Al(OH)4] + 2CO
2 Al
2O
3xH
2O + 2NaHCO
3
Al2O
3xH
2O 1473K
Al2O
3(s) + xH
2O
10. fuEufyf[kr esa ls lgh dFku@dFkuksa dk p;u dhft,A
(A) SnCl2.2H
2O ,d vipk;d gS
(B) SnO2 rFkk KOH fØ;k djds K
2[Sn(OH)
6] cukrs gS
(C) HCl esa PbCl2 ds foy;u esa Pb2+ rFkk Cl– vk;u gksrs gS
(D) Pb3O
4 dh xeZ o ruq ukbfVªd vEYk ds lkFk vfHkfØ;k ij PbO
2 izkIr gksrk gS tks ,d fjMkWDl vfHkfØ;k gS
mÙkj (A,B)
gy gy gy gy gy : LFkkf;Ro Øe Sn4+ > Sn2+ ...
Sn2+ vipk;d ds :i esa dk;Z djsxk
SnO2 + 2KOH + 2H
2O K
2[Sn(OH)
6]
lkanz HCl esa PbCl2 DyksjksIyEcl vEy ds :i esa ik;k tkrk gS] H
2[PbCl
4] PbCl
2 + 2HCl H
2[PbCl
4]
Pb3O
4 + 4HNO
3 2Pb(NO
3)2 + PbO
2 + 2H
2O
(2PbO + PbO2)
11. uhps fn, x, pkj ;kSfxdksa I, II, III rFkk IV ij fopkj dhft,A
N
H C3
CH3
NH2
NH2
NO2
O N2
NO2
N
NO2
O N2
NO2
H C3
CH3
I II
III IV
JEE (ADVANCED)-2020 (Paper-2)
22
lgh dFku@dFkuksa dk p;u dhft,A
(A) {kkjdrk dk Øe II > I > III > IV gS
(B) I rFkk II ds eè; pKb ds ifjek.k dk vUrj III rFkk IV ds eè; pK
b ds ifjek.k ds vUrj ls vfèkd gSS
(C) III esa vuqukn izHkko IV eas vuqukn izHkko ls vfèkd gS
(D) f=kfoe izHkko ;kSfxd IV dks III dh vis{kk vfèkd {kkjh; cuk nsrk gS
mÙkj (C,D)
gy gy gy gy gy : {kkjdrk dk Øe: II > I > IV > III
IV esa f=kfoe izHkko ds dkj.k–N(Me)2 ry dss ckgj dh vksj gksxk
blfy, oy; ds lkFk N dk vuqukn ?kVsxk rFkk {kkjh; izdfr c<+sxhA
12. ;kSfxd P ds fuEufyf[kr :ikUrj.kksa ij fopkj dhft,
R( )izdkf'kd lfØ;
(i) NaNH2
(ii) C H COCH36 5
(iii) H O /3
+
P(C H )
9 12
(i) X ( )vfHkdeZd
(ii) KMnO /H SO /4 2 4
Q(C H O )
8 12 6
( )izdkf'kd lfØ; vEy
CH3
Pt/H2
lgh fodYi dk p;u dhft,A
(A) P; gS
(B) X, Pd-C/fDouksyhu/H2 gS
(C) P; gS
(D) R; gS
mÙkj (B,C)
Sol. P
X Pd-C/fDoukWy/H2
R
*
O
JEE (ADVANCED)-2020 (Paper-2)
23
(P)
X
(ii) KMnO /H SO /4 2 4
COOHCOOH
* COOH
(Q)
[k.M[k.M[k.M[k.M[k.M - 3 (vf/dre vadvf/dre vadvf/dre vadvf/dre vadvf/dre vad : 24)
bl [k.M esa N% (06) ç'u gSaA çR;sd ç'u dk mÙkj ,d vkafdd eku gSA
çR;sd ç'u ds fy,] mÙkj ds lgh vkafdd eku dks ekÅl rFkk vkWu&LØhu opqZvy U;weSfjd dh–iSM ds mi;ksx ls mÙkj çfo"V
djus ds LFkku ij gh çfo"V dhft;sA ;fn vakfdd eku esa nks ls vf/d n'keyo LFkku gks] rks çkIr eku dk nks n'keyo LFkku rd
lfUudVu djsaA
çR;sd ç'u ds mÙkj dk ewY;kadu uhps nh xbZ vadu ;kstuk ds vuqlkj fd;k tk;sxk:
iw.kZ vad : +4 ;fn dsoy lgh vakfdd eku dks çfo"V fd;k x;k gS_
'kwU; vad : 0 vU; lHkh fLFkfr;ksa esaA
13. 0.1 M nqcZYk {kkj (B) ds foy;u dks izcy vEy (HA) ds 0.1 M foy;u ds lkFk vuqekfir fd;k tkrk gSA feyk, x, vEy
HA ds vk;ru ds lkFk foy;u dh pH esa ifjorZu dks uhps fp=k n'kkZ;k x;k gSA {kkj dk pKb D;k gSaA mnklhuhdj.k vfHkfØ;k
B + HA BH+ + A– gSA HA
12
10
8
6
4
2
0 2 4 6 8 10 12
pH
HA (mL)dk vk;ru
mÙkj (3)
gy gy gy gy gy : B + HA BH+ + A–
rqY;rk fcUnq rd iz;qDr HA dk vk;ru = 6 mL (fn;s x, vkjs[k ls)
vèkZ rqY;rk fcUnq ij foy;u B rFkk BH+ okyk {kkjh; ciQj gSA
b
[BH ]pOH pK log
[B]
∵
JEE (ADVANCED)-2020 (Paper-2)
24
vèkZ rqY;rk fcUnw ij : [BH+] = [B]
pOH = pKb = 14 – 11 = 3
bpK 3
14. nzo A rFkk B, 25°C ij A rFkk B ds lHkh la?kVu ij vkn'kZ foy;u cukrs gSaA A ds 0.25 rFkk 0.50 eksy izHkkt okys ,sls nksfoy;uksa dk dqy ok"i nkc Øe'k% 0.3 rFkk 0.4 ckj gSa] 'kq¼ nzo B dk ckj esa ck"i nkc D;k gS\
mÙkj (0.2)
gy gy gy gy gy : jkÅYV fu;e ds mi;ksx ls
o o
T A A B BP x P x P
o o
A B0.3 0.25 P 0.75 P ... (i)
o o
A B0.4 0.5 P 0.5 P ... (ii)
(i) o (ii) ls
o
AP 0.6 bar
o
BP 0.2 bar
Ans 0.20
15. uhps fn;k x;k fp=k fLFkfrt ÅtkZ rFkk bysDVªkWuh; vkè;koLFkk esa H2 v.kq dh vUrj ukfHkdh; nwjh ds eè; vkjs[k dks n'kkZrk
gSAd = d0 ds fy, usV fLFkfrt ÅtkZ E
0 (fp=k esa fufn"V) dk eku kJ mol–1 esa D;k gS tgk¡ bysDVªkWu&bysDVªkWu izfrd"kZ.k rFkk
ukfHkd&ukfHkd izfrd"kZ.k ÅtkZ vuqifLFkr gSA lanHkZ ds vuqlkj tc bysDVªkWu rFkk ukfHkd vuUr :i ls cgqr nwj gks] rks Hijek.kq dh fLFkfrt ÅtkZ 'kwU; yh tkrh gS
vkoksxknzks la[;k 6.023 × 1023 mol–1 gS
H Hd
d0
vUrjukfHkdh; nwjh (d)
fLFkfr
t] ÅtkZ
(kJ
mo
l)
–1
E0
mÙkj (–5242.42)
JEE (ADVANCED)-2020 (Paper-2)
25
gy gy gy gy gy : tc bysDVªkWu rFkk ukfHkd vuUr nwjh ij gks rks H-ijek.kq dh fLFkfrt ÅtkZ 'kwU; ekuh tkrh gS (nh x;h gSZ).
vkè;koLFkk esa bysDVªkWu okys H-ijek.kq dh fLFkfrt ÅtkZ
= – 27.2 eV (cksgj izfr:i ls)
vUrj ukfHkdh; nwjh 'd0 ij bysDVªkWu&bysDVªkWu izfrd"kZ.k rFkk ukfHkd&ukfHkd izfrd"kZ.k vuqifLFkr gksrs gSA
nks H-ijek.kq dh fLFkfrt ÅtkZ = – 2 × 27.2 eV = – 54.4 eV
=
19 2354.4 1.6 10 6.023 10
kJ/mol1000
= – 5242.42 kJ/mol
16. uhps n'kkZ;h x;h P ls Q rd vfHkfØ;k vuqØe ij fopkj dhft,A P ls izkIr eq[; mRikn Q dh lEiw.kZ yfCèk 75% gSA
9.3 mL P ls izkIr Q dh xzke esa ek=kk D;k gS\ (P dk ?kuRo = 1.00 g mL–1; eksyj nzO;eku : C = 12.0, H = 1.0,
O = 16.0 rFkk N = 14.0 g mol–1)
NH2
P
(i) NaNO + HCl/0-5°C2
OHQ
+ NaOH(ii)
(iii) CH CO H/H O3 2 2
mÙkj (18.6)
gy gy gy gy gy :
NH2
N
N2Cl
(P)
(Q)
(i) NaNO + HCl/0-5°C 2
+ –
(ii) OH
,
N = N
O
CH CO H/H O3 2 2
OH
NNaOH
M.M. = 248
9.3 mL P 9.3 g P
P ds eksy = 9.30.1
93
izkIr Q ds eksy = 0.1 × 0.75 = 0.075
izkIr Q dk nzO;eku = 248 × 0.1 × 3
4 = 18.6 g
JEE (ADVANCED)-2020 (Paper-2)
26
17. dSflVsjkbV ls fVu dks dksd ds lkFk vip;u }kjk izkIr fd;k tkrk gSA uhps fn, x, vkadM+ks ls ml U;wure rki (K esa) dk
fuèkkZj.k dhft, ftl ij dksd }kjk dSflVsjkbM dk vip;u gksxk
298 K ij: fH°(SnO
2(s)) = –581.0 kJ mol–1,
fH°(CO
2(g)) = –394.0 kJ mol–1,
S°(SnO2(s)) = 56.0 J K–1 mol–1, S°(Sn(s)) = 52.0 J K–1 mol–1,
S°(C(s)) = 6.0 J K–1 mol–1, S°(CO2(g)) = 210.0 J K–1 mol–1.
ekuk ,UFkSYih rFkk ,UVªkWih rki ij fuHkZj ugha djrh
mÙkj (935)
gy gy gy gy gy : SnO2(s) + C(s) Sn(s) + CO
2(g)
o
rH 394 581 187 kJ/mol
o
rS 52 210 56 6 200 J/K mol
Tmin
(ftl ij vip;u gksxk) =
o
r
o
r
H935K
S
18. 0.05 M Zn2+ dk vEyhdr foy;u 0.1 M H2S }kjk larIr gSA ZnS ds vo{ksi.k dks jksdus ds fy, vko';d H+ dh U;wure
eksyj lkanzrk (M) D;k gS\
Ksp
(ZnS) = 1.25 × 10–22, H2S dk lEiw.kZ fo;kstu fu;rkad K
usV = K
1K
2= 1 × 10–21.
mÙkj (0.2)
gy gy gy gy gy : ZnS(s) 2 2Zn (aq) S (aq)
[Zn2+] = 0.05 M
[S2–]max
(vo{ksi.k jksdus ds fy,) = sp
2
K (ZnS)
[Zn ]
=
22211.25 10
2.5 10 M0.05
H2S 2H+ + S2–
2 2
1 2
2
[H ] [S ]K K
[H S]
2 2121 [H ] 2.5 10
1 100.1
2 1[H ]
25
1[H ] 0.2 M
5
Ans 0.20
JEE (ADVANCED)-2020 (Paper-2)
27
PART-III : MATHEMATICS
[ k.M - 1 (vf/ dre vad : 18)
bl [ k.M esa N% (06) ç' u gSaA
i zR; sd i z' u dk mÙkj 0 l s 9 (nksuksa l fEefyr ) rd dh i jkl esa , dy vadh; i w.kk±d gS
çR; sd ç' u ds fy, ] mÙkj ds l gh vkafdd eku dks ekÅl rFkk vkWu&LØhu opqZvy U; weSfjd dh–i SM ds mi ; ksx l s mÙkj çfo"Vdjus ds LFkku i j gh çfo"V dhft ; sA
çR; sd ç' u ds mÙkj dk ewY; kadu uhps nh xbZ vadu ; kst uk ds vuql kj fd; k t k; sxk:
i w.kZ vad : +3 ; fn dsoy l gh i w.kk±d eku dks çfo"V fd; k x; k gS_
' kwU; vad : 0 ; fn i z' u dk mÙkj ugha fn; k x; k gS
½.kkRed vad : –1 vU; l Hkh fLFkfr ; ksa esaA
1. , d l fEeJ l a[ ; k z ds fy, ] ekuk Re(z), z ds okLr fod Hkkx dks n'kkZrk gSA ekuk S l Hkh l fEeJ l a[ ; kvksa z dk l eqPp;
gS t ks z4 – |z|4 = 4i z2 dks l arq"V djrh gS] t gk¡ i 1 , r c |z1 – z2|2 dk U; wure l aHkkfor eku] t gk¡ z1, z2 S
rFkk Re(z1) > 0 ,oa Re(z2) < 0] gS_____
mÙkj (8)
gy% ekuk z2 = a + ib
z4 – |z|4 = 4iz2
(a2 – b2) + 2abi – (a2 + b2) = 4i(a + ib)
b2 = 2b rFkk ab = 2a
vr% z2 = 0 ;k z2 = + 2i, R
ekuk z = x + iy
x2 – y2 + 2xy = + 2i
xy = 1
z dk fcanqi Fk ,d l edks.kh; vfr i joy; xy = 1 gS
; fn Re(z1) > 0 rFkk Re(z2) < 0, rc
z1 o z2 ds eè; U; wure nwjh] bl vfr i joy; ds nks ' kh"kksZa dks feykus okyk js[ kk[ k.M gSA
2 21 2 min
z z (1 1) (1 1) 8
21 2 minz z 8
2. , d fel kbZy }kjk ,d y{; i j l i Qyrki woZd Vdjkus dh i zkf; drk 0.75 gSA y{; dks i w.kZr ; k u"V djus ds fy, fel kbZy ds
de l s de rhu ckj l i Qyrki woZd Vdjkus dh vko' ; drk gSA rc U;wure fdruh fel kbZy nkxh t k,a r kfd y{; dks i w.kZr ; k
u"V djus dh i zkf; drk 0.95 l s de u gks _____
mÙkj (6)
JEE (ADVANCED)-2020 (Paper-2)
28
gy% y{; i j Vdjkus dh i zkf; drk 3H
4
y{; l s pwd t kus dh i zkf; drk 1M
4
vHkh"V i zkf;drk de l s de 3 fel kbysa Vdjkrh gSa
; gk¡ 1 – (P(x = 0) + P(x = 1) + P(x = 2)) 0.9
; gk¡ P(x = r) n'kkZrk gS fd r fel kbysa Vdjkrh gSaA
; gk¡ n n 1 2 n 2
n n n0 1 2
1 3 1 3 11 C C C 0.95
4 4 4 4 4
n
2 2n 3 9n(n 1) 1202 4
...(1)
n ds fofHkUu eku j[ kus i j]
n dk y?kqÙke eku 6 i zkIr gksrk gSA
n = 5 ds fy, , l ehdj.k (1) dk L.H.S. gS 2120.10703125
2 1024
n = 6 ds fy, , l ehdj.k (1) dk L.H.S. gS 308 0.0750.037
2 4096 2
; gk¡ n = 6 fel kbysa nkxh t krh gSaA
3. ekuk O oÙk x2 + y2 = r2 dk dsUnz gS, t gk¡ 5
r2
, ekuk PQ bl oÙk dh t hok gS rFkk P o Q l s xqt jus okyh js[ kk dk
l ehdj.k 2x + 4y = 5 gSA ; fn f=kHkqt OPQ ds i fjoÙk dk dsUnz] js[ kk x + 2y = 4 i j fLFkr gS, rc r dk eku gS _____
mÙkj (2)
gy% P
O
Q
R(x , y )1 1M
2x + 4y = 5
OPQ dk i fjoÙk] OR dk eè; fcanq]
O ds funsZ' kkad = (0, 0)
ekuk R (x1, y1) gS] rc PQ dk l ehdj.k gS
xx1 + yy1 = r2
2x + 4y = 5 ds l kFk rqyuk djus i j , ; gk¡ :
21 1x y r
2 4 5
JEE (ADVANCED)-2020 (Paper-2)
29
2 2
1 12r 4r
R (x ,y ) ,5 5
i fjdsUnz 2 2r 2r
M ,5 5
M, x + 2y = 4 i j fLFkr gS
2 2r 4r
45 5
r2 = 4
r = 2
4. , d oxZ vkO; wg dk vuqjs[ k bl ds fod.kZ vo; oksa ds ; ksxi Qy ds : i esa i fjHkkf"kr gSA ; fn A , d 2 × 2 vkO; wg gS t cfd A
dk vuqjs[ k 3 gS rFkk A3 dk vuqjs[ k –18 gS, r c A ds l kjf.kd dk eku gS
mÙkj (5)
gy% ekuk 2x yA A 3x x yz
z 3 x
vc
2 x y x y
Az 3 x z 3 x
2 2
2 2
xy 3y xy 3yx yz x yz
xz 3z xz 3zyz 9 x 6x yz 9 x 6x
2
32
3y x yx yzA
3z z 3 xyz 9 x 6x
3 2 2
2 2 2 3 2
x xyz 3yz x y y z 9y 3xy
3xz yz 9z x z 6xz 6yz 27 3x 18x xyz 9x x 6x
vuqjs[ k 3 2 3 2x xyz 3yz 3yz 27 3x 18x xyz 9x x 6x 18
9yz + 9x2 – 27x + 27 = –18
yz + x2 – 3x + 3 = –2
x2 – 3x + yz = –5
3x – x2 – yz = 5
|A| = 5
5. ekuk i Qyu f : (–1, 1) rFkk g : (–1, 1) (– 1, 1) ,
f(x) = |2x – 1| + |2x + 1| rFkk g(x) = x - [x] }kjk i fjHkkf"kr gSA
t gk¡ [x], x l s NksVs ; k cjkcj egÙke i w.kkZad dks n' kkZrk gSA ekuk f o g: (–1, 1) , (f o g) (x) = f(g(x)) }kjk i fjHkkf"kr
l a; qDr i Qyu gSA ekuk c vUr jky (–1, 1) esa fcanqvksa dh l a[ ; k gS t gk¡ f o g l r r ugha gS rFkk ekuk d vUr jky (–1, 1) esa
fcanqvksa dh l a[ ; k gS t gk¡ f o g vodyuh; ugha gSA rc c + d dk eku gS _____
mÙkj (4)
JEE (ADVANCED)-2020 (Paper-2)
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gy% ; gk¡ f(x) = |2x – 1| + |2x + 1|
(fog)(x) = |2{x} – 1| + |2{x} + 1|
12x 1 2x 3 , x 1,
2
12x 1 2x 3 , x , 0
2fog x
12x 1 2x 1, x 0,
2
12x 1 2x 1, x , 1
2
12, x 1,
2
14x 4, x , 0
2fog (x)
12, x 0,
2
14x, x , 1
2
f(g(x)), x = 0 i j vl r r gS
rFkk
10, x 1,
2
14, x ,0
2fog x
10, x 0,
2
14, x ,1
2
f(g(x)), 1 1
x , 0,2 2
i j vuvodyuh; gS
c = 1 rFkk d = 3.
c + d = 4
6. l hek
x2
4 2 sin3x sinxlim
3x 5x 3x2sin2xsin cos 2 2 cos2x cos
2 2 2
dk eku gS_____
mÙkj (8)
gy%x
2
4 2(2sin2x cos x)lim
x 7x 5x 3xcox – cos cos – cos – 2(1 cos2x)
2 2 2 2
JEE (ADVANCED)-2020 (Paper-2)
31
2
2x2
16 2 cos x sinxlim
3x 5x2cos .cos x – 2cox .cosx – 2 2 cos x
2 2
2
2x2
16 2 cos x sinxlim
x2cosx 2sin2x sin – 2 2 cos x
2
x
2
16 2 sinx 16 2lim
x 4 2 – 2 28sinx sin – 2 22
= 8
[ k.M - 2 (vf/ dre vad : 24)
bl [ k.M esa N% (06) ç' u gSaA
çR; sd ç' u ds pkj fodYi gSaA bu pkj fodYi ksa eas l s ,d ;k ,d l s vf/ d l gh mÙkj gS@gSaA
çR;sd ç'u ds fy, (l Hkh) l gh mÙkjksa l s l acaf/ r fodYi @fodYi ksa dk p; u dhft ; sA
çR; sd ç' u ds mÙkj dk ewY; kadu uhps nh xbZ vadu ; kst uk ds vuql kj fd; k t k, xk:
i w.kZ vad : +4 ; fn dsoy l Hkh l gh fodYi @fodYi ksa dk p; u fd; k x; k gS_
vakf' kd vad : +3 ; fn l Hkh pkj fodYi l gh gSa i jUrq dsoy rhu fodYi ksa dk p; u fd; k x; k gS_
vakf' kd vad : +2 ; fn rhu ; k vf/ d fodYi l gh gSa i jUrq dsoy nks fodYi ksa dk p; u fd; k x; k gS rFkk nksuksa l ghgks_
vkaf' kd vad : +1 ; fn nks ; k vf/ d fodYi l gh gSa i jUrq dsoy ,d fodYi dk p; u fd; k x; k gS rFkk og l ghfodYi gks_
' kwU; vad : 0 ; fn fdl h Hkh fodYi dk p; u ugha fd; k x; k gSA (vFkkZr~ ç' u dk mÙkj ugha fn; k x; k gks);
½.kkRed vad : –2 vU; l Hkh fLFkfr ; ksa esaA
7. ekuk b , d v&' kwU; okLr fod l a[ ; k gSA ekuk f : , d vodyuh; i Qyu gS t cfd f(0) = 1, ; fn f dk vodyt f
l ehdj.k
2 2
f(x)f (x)
b x
dks l Hkh x ds fy, l arq"V djrk gS, r c fuEu esa l s dkSul k dFku l R; gS@gSa\
(A) ; fn b > 0, rc f ,d o/ Zeku i Qyu gS
(B) ; fn b < 0, rc f ,d gzkl eku i Qyu gS
(C) l Hkh x ds fy, f(x)f(–x) = 1
(D) l Hkh x ds fy, f(x) – f(–x) = 0
mÙkj (A, C)
gy% 2 2
f x 1f x b x
2 2
f (x) dxdx c
f(x) b x
JEE (ADVANCED)-2020 (Paper-2)
32
ln 11 xf(x) tan c
b b
( f(0) = 1 c = 0)
11 x
tanb bf(x) e
vr% 11 x
tanb bf(x) e
; k
11 xtan
b bf(x) e
ysfdu f(0) = 1, bl fy, 11 x
tanb bf(x) e
f(x) > 0, b ds l Hkh ekuksa ds fy,
8. ekuk a o b / ukRed okLr fod l a[ ; k, a gSa t cfd a > 1 r Fkk b < a, ekuk P i zFke pr qFkkZa' k esa , d fcanq gS t ks
vfr i joy; 2 2
2 2
x y– 1
a b i j fLFkr gSA ekuk P i j vfr i joy; dh Li ' kZ js[ kk fcanq (1, 0) l s xqt jrh gS rFkk ekuk P i j vfr i joy;
dk vfHkyEc funsZ' kkad v{kksa i j l eku vUr%[ k.M dkVrk gSA ekuk P i j Li ' kZ js[ kk] P i j vfHkyEc ,oa x-v{k }kjk fufeZrf=kHkqt dk {ks=ki Qy gSA ; fn e vfr i joy; dh mRdsUnzrk gS] rc fuEu esa l s dkSul k@l s dFku l R; gS@gSa\
(A) 1 e 2 (B) 2 e 2
(C) 4a (D) 4b
mÙkj (A, D)
gy%
P(asec , btan )
(1, 0)A 2 2a b ,0
B
ekuk P (asec, btan)
x yT : sec tan 1
a b
(1, 0), Li ' kZ js[ kk i j fLFkr gS] bl fy, a = sec
2 2ax byN: a b
sec tan
vfHkyEc dh i zo.krk –1 gS, vr% a
sin 1b
b = tan
vr%, a2 – b2 = 1
2 2
2 2 2
b a 1 1e 1 1 2
a a a
D;ksafd a > 1, bl fy, e 1, 2
PAB dk {ks=ki Qy 2 21a b 1 .b tan
2
2 2 4 412tan tan tan b
2
JEE (ADVANCED)-2020 (Paper-2)
33
9. ekuk i Qyu f : rFkk g:
f(x + y) = f(x) + f(y) + f(x)f(y) rFkk f(x) = xg(x)
dks l Hkh x, y ds fy, l arq"V djr s gSaA ; fn
x 0lim g(x) 1, r c fuEu esa l s dkSul k@l s dFku l R; gS@gSa\
(A) f i zR; sd x i j vodyuh; gS
(B) ; fn g(0) = 1, rc g i zR; sd x i j vodyuh; gS
(C) vodyt f(1), 1 ds cjkcj gS
(D) vodyt f(0), 1 ds cjkcj gS
mÙkj (A, B, D)
gy%
h 0
f(x h) f(x)f (x) lim
h
h 0
f(x) f(h) f(x) f(h) f(x)f (x) lim
h
h 0
f(h)f (x) lim (1 f(x))
h
f (x) 1 f(x)
f (x)
11 f(x)
ln(1 + f(x)) = x + c 1 + f(x) = ex + c ( f(0) = 0 c = 0) f(x) = ex – 1 f(x) = ex
10. ekuk , , , okLr fod l a[ ; k, a gSa t cfd 2 + 2 + 2 0 r Fkk + = 1, ekuk fcanq (3, 2, –1) l er yx + y + z = ds l ki s{k fcanq (1, 0, –1) dk ni Z.k i zfr fcEc gSA rc fuEu esa l s dkSul k@l s dFku l R; gS@gSa\(A) + = 2 (B) – = 3
(C) + = 4 (D) + + =
mÙkj (A, B, C)
gy% P(3, 2, –1) o Q(1, 0, –1), ; fn P dk l ery ds l ki s{k i zfr fcEc Q gSA rc PQ , l ery i j vfHkyEc gS rFkk PQ dk
eè; fcanq l ery i j fLFkr gSA: 1 (x – 2) + 1 (y – 1) + 0 (z + 1) = 0 : x + y = 3
Li "Vr% = 0, vr% = 1 (D;ksafd + = 1)
rc = 1 rFkk = 3
11. ekuk a o b / ukRed okLr fod l a[ ; k,a gSaA ekuk ˆ ˆPQ ai bj
rFkk ˆ ˆPS ai – bj
, d l ekUr j prqHkqZt PQRS dh vkl Uu
Hkqt k, ¡ gSaA ekuk u o v
, Øe'k% P Q P So ds vuqfn'k ˆ ˆw i j
ds i z{ksi l fn' k gSaA ; fn u v w
rFkk ; fn l ekUr j
prqHkqZt PQRS dk {ks=ki Qy 8 gS, r c fuEu esa l s dkSul k@l s dFku l gh gS@gSa\(A) a + b = 4
(B) a – b = 2
(C) l ekUr j prqHkqZt PQRS ds fod.kZ PR dh yEckbZ 4 gS
(D) w
, l fn' kksa PQ PSrFkk dk dks.k v¼Zd gS
mÙkj (A, C)
JEE (ADVANCED)-2020 (Paper-2)
34
gy%
2 2 2 2
a b a – bv u
a b a b
rFkk
2 2
a b a – bv u w 2
a b
WLOG, a b
bl fy,
2 22a a b
a = b
rFkk PQRS dk {ks=ki Qy PQ PS 2ab 8
vr% a = b = 2, bl fy,
2 2PQ PS a – b 0
vr% PQRS, Hkqt k yackbZ2 2 okyk ,d oxZ gSA
12. v&½.kkRed i w.kkZadksa s o r ds fy, , ekuk
s! r s,
s r!(s –r)!
r0 r s.
; fn
; fn
/ ukRed i w.kkZadksa m o n ds fy, , ekuk
m n
p 0
f(m,n,p)g(m,n)
n p
p
t gk¡ fdl h v&½.kkRed i w.kkZad p ds fy, ,
p
i 0
m n i p nf(m,n,p) ,
i p p – i
r c fuEu esa l s dkSul k@l s dFku l R; gS@gSa\
(A) l Hkh / ukRed i w.kkZadksa m, n ds fy, g(m, n) = g(n, m)
(B) l Hkh / ukRed i w.kkZadksa m, n ds fy, g(m, n + 1) = g(m + 1, n)
(C) l Hkh / ukRed i w.kkZadksa m, n ds fy, g(2m, 2n) = 2g(m, n)
(D) l Hkh / ukRed i w.kkZadksa m, n ds fy, g(2m, 2n) = (g(m, n))2
mÙkj (A, B, D)
gy%
pm
ii 0
p nn if(m,n,p) C
p n i – p n i p – i
p
mi
i 0
n p 1f m,n,p C
p p – i n – (p – i)
JEE (ADVANCED)-2020 (Paper-2)
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p
m ni p–i
i 0
n pf m,n,p C C
n p
m n n p m np p p
n pf m,n,p C C C
n p
m nm n m n
pp 0
g(m,n) C 2
[ k.M - 3 (vf/ dre vad : 24)
bl [ k.M esa N% (06) ç' u gSaA çR; sd ç'u dk mÙkj , d vkafdd eku gSA
çR; sd ç' u ds fy, ] mÙkj ds l gh vkafdd eku dks ekÅl rFkk vkWu&LØhu opqZvy U; weSfjd dh–i SM ds mi ; ksx l s mÙkj çfo"Vdjus ds LFkku i j gh çfo"V dhft ; sA ; fn vakfdd eku esa nks l s vf/ d n' keyo LFkku gks] r ks çkIr eku dk nks n' keyo LFkku rdl fUudVu djsaA
çR; sd ç' u ds mÙkj dk ewY; kadu uhps nh xbZ vadu ; kst uk ds vuql kj fd; k t k; sxk:
i w.kZ vad : +4 ; fn dsoy l gh vakfdd eku dks çfo"V fd; k x; k gS_
' kwU; vad : 0 vU; l Hkh fLFkfr ; ksa esaA
13. , d vfHk; ark dks i zR; sd ekg ds i gys 15 fnuksa ds nkSjku Bhd pkj fnu dkj[ kkus dk Hkze.k djuk vko' ; d gS rFkk ; gvfuok; Z gS fd og yxkrkj nks fnu Hkze.k ugha djsxk] r c mu l Hkh l aHkkfor r jhdksa dh l a[ ; k ft uesa vfHk; ark 1-15 t wu2021 ds nkSjku dkj[ kkus esa Hkze.k dj l drk gks] gS _____
mÙkj (495)
gy% ekuk ;g 1st ckj Hkze.k i j x1 fnuksa ds i ' pkr t krk gS
2nd ckj Hkze.k i j x2 fnuksa ds i ' pkr t krk gS
3rd ckj Hkze.k i j x3 fnuksa ds i ' pkr t krk gS
4th ckj Hkze.k i j x4 fnuksa ds i ' pkr t krk gS
rFkk rc ' ks"k x5 fnu gS
x1 + x2 + x3 + x4 + x5 = 11
x1, x5 0 rFkk x2, x3, x4 1
gyksa dh l a[ ; k = 12C4 = 12 11 10 9
55.9 4954 3 2
14. , d gksVy esa] pkj dejs mi yC/ gSaA N% O; fDr bu pkj dejksa esa bl i zdkj j[ ks t krs gSa fd buesa l s i zR; sd dejs esa de l sde ,d o vf/ d l s vf/ d nks O; fDr gksaA rc , sl k dqy fdrus r jhdksa l s fd; k t k l drk gS\
mÙkj (1080)
gy% l ewg gksaxs dsoy 2, 2, 1, 1
O; fDr dk l ewg esa foHkkt u = 22 2
6!
(2!) (1!) 2!
bUgsa O; ofLFkr djus ds r jhdksa dh l a[ ; k = 4
6!4! 1080
(2!)
JEE (ADVANCED)-2020 (Paper-2)
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15. nks fu"i {k i kl s ft uesa l s i zR; sd ds i Qydksa i j 1,2,3,4,5 o 6 l a[ ; k, ¡ vafdr gSa, , d l kFk yq<+dk, t krs gSa rFkk i Qydksa i jvk;h gq; h l a[ ; kvksa dk ; ksxi Qy ; kn j[ kk t krk gSA ;g i zfØ; k r c rd nksgjkbZ t krh gS t c rd ; ksxi Qy ; k r ks ,d vHkkT;l a[ ; k ; k ,d i w.kZ oxZ i zkIr u gks t k,A ekuk ,d vHkkT; l a[ ; k i zkIr gksus l s i gys ,d i w.kZ oxZ i zkIr gksrk gSA ; fn bl i w.kZoxZ l a[ ; k ds ,d fo"ke l a[ ; k gksus dh i zkf;drk p gS] rc 14p dk eku gS _____
mÙkj (8)
gy% i fj.kke r jhdksa dh l a[ ; k
i w.kZ oxZ 1, 4, 9 7 (1 dHkh ugha vk,xk)
vHkkT; 2, 3, 5, 7, 11 15
' ks"k 6, 8, 10, 12 14
nh x; h i zfØ; k dk ,d i w.kZ oxZ }kjk l ekIr gksuk = E (ekuk ?kVuk dk uke)
rFkk i zfØ; k dk ,d fo"ke oxZ }kjk l ekIr gksuk = O (ekuk ?kVuk dk uke)
OP
E Kkr djus gsrq
P(O E)
P(E)
P(O E) = 1, 4, 2, 3, 5, 7, 11 l s i gys 9 vkus dh i zkf; drk
24 4 14 14 4......
36 36 36 36 36
P(E) = 2, 3, 5, 7, 11 l s i gys 4 ; k 9 vkus dh i zkf; drk
27 14 7 14 7......
36 36 36 36 36
4O 436P p
7E 736
14p = 8
16. ekuk i Qyu f : [0, 1] fuEu }kjk i fjHkkf"kr gSx
x
4f(x)
4 2
.
rc
1 2 3 39 1f f f ..... f f
40 40 40 40 2
dk eku gS _____
mÙkj (19)
gy% f(x) = x
x
4
4 2
x 1 x
x 1 x
4 4f x f 1 x 1
4 2 4 2
1 2 3 39 1
f f f .... f f40 40 40 40 2
JEE (ADVANCED)-2020 (Paper-2)
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= 1 39 2 38 1
f f f f .... f40 40 40 40 2
= 20 11 1 ... 19 f f
40 2
i n
= 19
17. ekuk f : , d vodyuh; i Qyu gS t cfd bl dk vodyt f' l r r gS r Fkk f()=–6, ; fn F : [0, ] ,x
0F(x) f(t)dt }kjk i fjHkkf"kr gS, rFkk ; fn
0
f (x) F(x) cosx dx 2
,
r c f(0) dk eku gS __________
mÙkj (4)
gy% F(x) = f(x) bl fy, F() = –6
0
f (x) F(x) cos x dx
=0 0
F (x)cosx dx F(x)cosx dx
= 0 0 0
F x cos x sinx.F x dx F x cos xdx
= 0 0 0
F F 0 sinx.F x cosx.F x dx F(x)cosx dx
= 6 – F(0)
6 – F(0) = 2
F(0) = 4 = f(0)
18. ekuk i Qyu f : (0, ) , 2 4f( ) (sin cos ) (sin cos ) }kjk i fjHkkf"kr gSA
ekuk i Qyu f dk i j LFkkuh; fufEu"B gS t c 1 r{ ,......, }, t gk¡ 0 < 1 < .... r < 1, rc 1 + .... + r dk eku gS_______
mÙkj (0.50)
gy% f() = (sin + cos)2 + (sin – cos)4
ekuk (sin + cos)2 = x
f() = x + (2 – x)2 = x2 – 3x + 4
23 7
f( ) x –2 4
JEE (ADVANCED)-2020 (Paper-2)
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f() y?kqÙke gS t c 3
x2
3
sin cos2
3
sin4 2
2
4 3 3
; k 5
12 12 ; k
vr%, 11
12 rFkk 2
512
1 212
= 0.50