1

Answers & Solutions

forforforforfor

JEE (Advanced)-2017

Time : 3 hrs. Max. Marks: 183

CODE

1

Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005

Ph.: 011-47623456 Fax : 011-47623472

PAPER - 2 (Code - 1)

DATE : 21/05/2017

INSTRUCTIONS

QUESTION PAPER FORMAT AND MARKING SCHEME :

1. The question paper has three parts : Physics, Chemistry and Mathematics.

2. Each part has three sections as detailed in the following table :

Section QuestionType

Number of Questions

Full Marks

Category-wise Marks for Each Question

Partial Marks Zero Marks Negative Marks

MaximumMarksof the

Section

SingleCorrectOption

7 +3If only the bubble corresponding to the correct option

is darkened

0If none of the

bubbles is darkened

1In all other

cases

211

One ormore

correctoption(s)

7 +4If only the bubble(s)

corresponding toall the correct

option(s) is(are)darkened

+1For darkening a bubblecorresponding to each

correct option, provided NO incorrect option is

darkened

0If none of the

bubbles is darkened

2In all other

cases

282

Compre-hension

4 +3If only the bubblecorresponding to

the correct answeris darkened

0In all other

cases

123

fgUnh ek;efgUnh ek;efgUnh ek;efgUnh ek;efgUnh ek;e

2

JEE (ADVANCED)-2017 (PAPER-2) CODE-1

PHYSICS

[kaM[kaM[kaM[kaM[kaM-1(vf/dre vad (vf/dre vad (vf/dre vad (vf/dre vad (vf/dre vad : 21)))))

bl [kaM esa lkrlkrlkrlkrlkr iz'u gSaA

R;sd iz'u ds pkjpkjpkjpkjpkj fodYi (A), (B), (C) vkSj (D) gSa ftuesa fliZQ ,d ,d ,d ,d ,d fodYi lgh gSA

izR;sd iz'u ds fy, vks-vkj-,l- ij lgh mkj ds vuq:i cqycqys dks dkyk djsaA

izR;sd iz'u ds fy, vad fuEufyf[kr ifjfLFkfr;ksa esa ls fdlh ,d ds vuqlkj fn;s tk,saxs %fdlh ,d ds vuqlkj fn;s tk,saxs %fdlh ,d ds vuqlkj fn;s tk,saxs %fdlh ,d ds vuqlkj fn;s tk,saxs %fdlh ,d ds vuqlkj fn;s tk,saxs %

iw.kZ vad : +3 ;fn dsoy lgh fodYi ds vuq:i cqycqys dks dkyk fd;k gSA

'kwU; vad : 0 ;fn fdlh cqycqys dks dkyk ugha fd;k gSA

.k vad : 1 vU; lHkh ifjfLFkfr;ksa esaA

1. ,d izlkjh xksys (expanding sphere) dh rkR{kf.kd (instantaneous) f=kT;k R ,oa nzO;eku M vpj jgrs gSA izlkj ds nkSjku

bldk rkR{kf.kd ?kuRo iwjs vk;ru esa ,dleku jgrk gS ,oa vkaf'kd ?kuRo dh nj 1 d

dt

vpj (constant) gSA bl izlkjh

xksys ds i"B ij ,d fcUnq dk osx v fuEu ds lekuqikrh gksxk

(A) R (B) R3

(C)1

R(D) R2/3

mkjmkjmkjmkjmkj (A)

gygygygygy 34

3M R=

2 340 3

3

dR dR R

dt dt

= +

ls foHkkftr djus ij

2 3 10 3

dR dR R

dt dt

= +

2 33

dRR R K

dt=

dRR

dt

2. fp=k }kjk n'kkZ;s lecgqHkqtksa dh Hkqtkvksa dh la[;k n = 3,4,5....... gSA lHkh cgqHkqtksa dk lagfr dsUnz (center of mass) vuqHkwfed

ry ls h pkbZ ij gSA ;s fcuk fiQlys f{kfrt ry ij izfrxkeh 'kh"kZ (leading vertex) ds pkjksa vkSj ?kw.kZu dj vxzlfjr gks jgs

gSaA izR;sd cgqHkqt ds lagfr dsanz ds js[kkiFk (locus) dh pkbZ dh vfkdre o`f gSA rc dh h vkSj n ij fuHkZjrk

fuEu esa ls nh tk,xh

h h h

3

JEE (ADVANCED)-2017 (PAPER-2) CODE-1

(A)2

sinhn

=

(B)1

1

cos

h

n

=

(C)2

sinhn

=

(D)2

tan2

hn

=

mkjmkjmkjmkjmkj (B)

gygygygygy lh

/n

2 n

=

sin cos

n

=

sin

hl =

= l h

= 1

1sin

h

= 1

1

cos

h

n

3. izdk'k fo|qr inkFkZ (photo electric material) ftldk dk;Z iQyu (work funtion) 0 gS] rjax&nS;Z

0

hc

4

JEE (ADVANCED)-2017 (PAPER-2) CODE-1

4. tSls dh fpf=kr fd;k x;k gS] ,d lfEer rkjs (symmetric star) ds vkdkj ds pkyd esa vifjofrZr kkjk I cg jgh gSA ;gk

foijhr 'kh"kks (diametrically opposite vertices) ds chp nwjh 4a gSA pkyd ds dsUnz ij pqEcdh; {ks=k dk eku gksxk

4a

I

(A)I

a

06 3 1

4

(B)I

a

06 3 1

4

+

(C)I

a

03 3 1

4

(D)I

a

03 2 3

4

mkjmkjmkjmkjmkj (A)

gygygygygy rkjs vkdkj ds pkyd ywi ds ,d Hkkx dks lefer ls ckgj ekuus ij

T;kferh lsT;kferh lsT;kferh lsT;kferh lsT;kferh ls :

30

30

30

120

2a

I

O

a

( )ywi dk dsUnz

lHkh 12 le:i Hkkxksa ds dkj.k ywi ds dsUnz ij pqEcdh; {ks=k izoQfr esa ;ksxkRed gSA

BusV = [ ]0

12 cos30 cos1204

I

a

+

= 0

6 3 14

I

a

5. rhu osDVj ,P Q

,oa R

fp=k }kjk n'kkZ, x, gSaA osDVj R

ij ,d fcUnq S n'kkZ;k x;k gSA fcUnq P o fcUnq S ds chp dh

nwjh b R

gSA,P Q

,oa S

osDVjksa ds chp lEcUk gS

SQ

PbR| |

R Q P=

QS

P

O X

Y

(A) ( )21S b P bQ= +

(B) ( )1S b P bQ= +

(C) ( )1S b P bQ= +

(D) ( ) 21S b P b Q= +

mkjmkjmkjmkjmkj (A)

5

JEE (ADVANCED)-2017 (PAPER-2) CODE-1

gygygygygy S

= | |P b R R+

= | || |

RP b R

R+

= P bR+

= ( )P b Q P+

= (1 )b P bQ+

6. jkdsV Hkwry ds vfHkyacor lw;Z ,oa i`Foh dks tksM+us okyh js[kk esa lw;Z ls nwj dh rjiQ (radially outward from the direction

of the sun) iz{ksfir fd;k x;k gSA lw;Z iFoh ls 3 105 xquk Hkkjh gS ,oa iFoh dh f=kT;k ls 2.5 104 xquh nwjh ij fLFkr gSA

i`Foh ds xq:Rokd"kZ.k {ks=k ds fy, iyk;u xfr 11.2 kms1 gSA jkdsV dks lw;Z ,oa i`Foh fudk; ds xq:Rokd"kZ.k ls eqDr gksus

ds fy, de ls de izkjafHkd osx (S) dk fudVre eku gS

(iFoh dh ph; xfr vkSj ifjHkze.k rFkk fdlh vU; xzg dh mifLFkfr dh mis{kk djsa)

(A) vs = 22 km s1 (B) v

s = 42 km s1

(C) vs = 62 km s1 (D) v

s = 72 km s1

mkjmkjmkjmkjmkj (B)

gygygygygy Evs

m

M M1 =

S

r R = 2.5 10 4

M M2 = 3 10

5

KE esa gkfu = PE esa ykHk

2 1 212

s

GM m GM mmv

R r= +

5

2

4

1 3 10

2 2.5 10s

GM G Mv

R R= +

2 13sGM

vR

=

= 11.2 13 40.4 km/s=

42 km/s

7. ,d O;fDr ,d iRFkj dks dq,as esa fxjkrs le; vkSj dq,as dh ryh esa la?kV ls mRiUUk ofu ds le; varjky dk ekiu djds

dq,as dh xgjkbZ dk irk yxkrk gSA og le;karjky ds ekiu esa =kqfV T = 0.01 lsdsaM ,oa dq,sa dh xgjkbZ L = 20 m ekirk gSA

xq:Rokd"kZ.k Roj.k g = 10 m s1 ,oa ofu xfr 300 ms1 nh xbZ gSA L/L ds ekiu esa fudVre vkaf'kd =kqfV (fractional

error) gS

(A) 0.2%

(B) 1%

(C) 3%

(D) 5%

mkjmkjmkjmkjmkj (B)

6

JEE (ADVANCED)-2017 (PAPER-2) CODE-1

gygygygygy t1 =

2L

g

t1

t2L

t2 =

L

V

T = t1 + t

2

T = 2L L

g V+

T = 2 1 1

2L L

g VL +

0.01 = 1 1 1

3005 2 20L

+

0.01 = 1 1

20 300L

+

0.01 = (15 1)

300L

+

L = 0.01 300

16

100L

L

= 3

10016 20

= 1%

[kaM[kaM[kaM[kaM[kaM-2 (vf/dre vad (vf/dre vad (vf/dre vad (vf/dre vad (vf/dre vad : 28)))))

bl [kaM esa lkrlkrlkrlkrlkr iz'u gSaA

R;sd iz'u ds pkjpkjpkjpkjpkj fodYi (A), (B), (C) vkSj (D) gSa ftuesa ,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 fodYi lgh gSaA

izR;sd iz'u ds fy, vks-vkj-,l- ij lkjs lgh mkj (mkjksa) ds vuq:i cqycqys (cqycqyksa) dks dkyk djsaA

izR;sd iz'u ds fy, vad fuEufyf[kr ifjfLFkfr;ksa esa ls fdlh ,d ds vuqlkj fn;s tk,axs %fdlh ,d ds vuqlkj fn;s tk,axs %fdlh ,d ds vuqlkj fn;s tk,axs %fdlh ,d ds vuqlkj fn;s tk,axs %fdlh ,d ds vuqlkj fn;s tk,axs %

iw.kZ vad : +4 ;fn fliQZ lkjs lgh fodYi (fodYiksa) ds vuq:i cqycqys (cqycqyksa) dks dkyk fd;k gSA

vkaf'kd vad : +1 izR;sd lgh fodYilgh fodYilgh fodYilgh fodYilgh fodYi ds vuq:i cqycqys dks dkyk djus ij] ;fn dksbZ xyr fodYi dkyk

ugha fd;k gSA

'kwU; vad : 0 ;fn fdlh cqycqys dks dkyk ughaughaughaughaugha fd;k gSA

.k vad : 2 vU; lHkh ifjfLFkfr;ksa esaA

mnkgj.k % ;fn ,d iz'u ds lkjs lgh mkj fodYi (A), (C) vkSj (D) gSa] rc bu rhuksa ds vuq:i cqycqyksa dks dkyk djus ij

+4 vad feysaxs_ fliQZ (A), (D) ds vuq:i cqycqyksa dks dkyk djus ij +2 vad feysaxsa_ rFkk (A) vkSj (B) ds vuq:i cqycqyksa

dks dkyk djus ij 2 vad feysaxs D;ksafd ,d xyr fodYi ds vuq:i cqycqys dks Hkh dkyk fd;k x;k gSA

7

JEE (ADVANCED)-2017 (PAPER-2) CODE-1

8. ,dleku pqEcdh; {ks=k (uniform magnetic field) B dkxt ds ry ds vfHkyEc fn'kk esa x = 0 ,oa 3

2

Rx = ds chp ds

{ks=k (fp=k esa region 2) esa loZ=k (tSls fd fp=k esa fn[kk;k gS) mifLFkr gSA ,d d.k ftldk vkos'k +Q ,oa laosx p gS] og

x-v{k ds vuqfn'k {ks=k 2 esa fcUnq P1(y = R) ij os'k djrk gSA fuEu esa ls dkSu lk(ls) dFku lgh gS@gSa\

3 /2R

( = )y R

+Q P1

OP

2

B

x

yRegion 1 Region 2 Region 3

(A)2

3

pB

QR> ds fy, d.k {ks=k 1 (region 1) esa iqu% os'k djsxk

(B)8

13

pB

QR= ds fy, d.k {ks=k 3 (region 3) esa x-v{k ij fcUnq P

2 ls os'k djsxk

(C) tc d.k lcls yEcs lEHkoiFk ls {ks=k 2 (region 2) ls {ks=k 1 (region 1) esa iqu% os'k djrk gS] rc fcUnq P1 vkSj y-v{k

ls lcls nwj fcUnq ds fy, jsf[kd laosx ds ifjek.k esa cnyko / 2p gS

(D) ,d fu;r B ds fy, ,eleku vkos'k Q ,oa ,d leku osx v okys d.kksa ds fy, fcUnq P1 ,oa {ks=k 1 (region 1) esa iqu%

os'k fcUnq dh nwjh dk varj d.kksa ds O;eku ds O;qrekuqikrh gS

mkjmkjmkjmkjmkj (A, B)

gygygygygy d.k pqEcd