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Page 1: Solution_jee Main Part Test-1

[1]TAITS / JM / PT-1 / 2016IITian’s TAPASYA...IITians creating IITians

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IITian’s TAPASYA

SOLUTION PAPER OF JEE MAIN 2016PART TEST - 1

DATE : 11th Oct. 2015

Ph.: 7857966777 / 8102926611/12/13Head Office : Pushpanjali Place, Boring Road, Patna-1

Branch Office : Rukanpura Flyover, Near Sri Sai Yamaha, Bailey Road, Patna-14, Mob. : 7677222110

www.iitianstapasya.com

IITian’s TAPASYA...IITians creating IITians

JEE (MAIN & ADV.) / NTSE / KVPY / OLYMPIAD

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PHYSICSQ.1 (A)

Sol. Acceleration of blocks = 70 30

10

4 m/s2

Velocity at t = 2.5 is

v = u + at = 0 + 4(2.5) = 10 m/s2

After stopping B, A continues to move up with acceleration g downward.

B comes down with acceleration g.

String will tight again when their displacement become equal.

SA = SB

2 21 110 t gt gt t 1 sec2 2

AV 10 g(1) 0 m / s

Q.2 (D)

Sol. If Range is 6 m2

o ou sin26 18.5 ,71.5g

For R = 8 mo o26.5 ,63.5

For sucessful shot range of .o o o o18.5 26.5 and 63.5 71.5

Q.3 (B)

Sol. FBD of blocks in the frame of lift

2 4

T T

2g 4g2g 4g

a a

NLM equations.

16gT 4g 2a 8g T 4a T3

reading of spring balance 2T 32g 3

SOLUTION OF JEE MAIN PART TEST - 1

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Q.4 (C)

Sol. By symmetry all will meet at centre. Comp. of velocity towards centre v 3vcos302

this is

also equal to avg. velocity.

v 30 v cos30o

A

B C

Q.5 (B)

Sol.

F

Fcosf

Fsin

N mg

N mg FsinFcos N (mg Fsin )

gFcos sin

For minimum Force dF 0 tand

min. 2

mgF1

contact force = 2 2N f

Q.6 (A)

Sol. FBD of block in frame of elevator

mg2 m

gsin

mgN

acceleration along the incline = 2gsin

2

2

1S ut at2

h 1o (2gsin )tsin 2

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Q.7 (D)

Sol.

m1 m1

m2 m2

v

v

m g2

m g1 T

R B

R BT

1

2

R B T m g ....(i)R B T m g ....(ii)

1 2

2 1

T m g T m g1T (m m )g2

Q.8 (C)

Sol.Wsin

Wsin8

f k

f k

20

Net force will be zero.

k

k

W sin f 20 ...(i)8 W sin f ....(ii)

from (i) and (ii) fk = 14

Q.9 (D)

Sol. At x = 1 m

U = 3, K = 1 Total = 4J

When particle moves to the right of x = 1 its kinetic energy increase.

But beyond x = 2, KE decreases And force is along – ve x axis.

It will reverse its direction where K = 0, U = 4 that is at x = 6.

Q.10 (A)

Sol.A

(0,0,0) (15,0,0)

VAB B

VAB must be along AB.AB is along x axis.

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AB

A B B A

B

B

V V i

V V V i V V Vi

V 15 i 4j 3k V i

(15 V)i 4j 3k

| V | 13 m / sV 3

Q.11 (B)

Sol. Area under F-t graph = change in momentum

f i13 1 2 2 V V2

Q.12 (B)

Sol. FBD before cut

3 2

60o 60o

Kx1 Kx2

2gKx2

Kx = 2g2 Kx = 5g1 ,

Kx1

3g

After cut,

3 2

5g/2

5g2g

Net force

3g

5g

5g 32

5g 32

5g2

= 5g

Acceleration of 3 kg 25g 50 m / s3 3

Acceleration of 2 kg = 0

Q.13 (C)

Sol.

N

x

yma

mg

FBD wrt wedge

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Work energy theorem

Wg + Wpseudo + WN = 0

– mgy + max = 0 2xy x x 4 y

4

Q.14 (B)

Sol. mgsin mgcos

5mgsin mgcos

23

ll

Q.15 (C)

Sol.2

4

10

6Let blocks move together.

210 6 2a m / s6 3

FBD of 2 kg 2 10f

max

2 4 2610 f 2 f 10 N3 3 3

f 8N f

so, blocks move separately.

2 108

10 8a 12

86

4 8 6a 0.54

Q.16 (C)

Sol.

Vmr

Vr

Resultant of Vmr and Vr is along 53o with Horizontal.

o omr

r mr

V cos 4tan53 0V V sin 3

mr

d 600t 30secV 20

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Q.17 (C)

Sol. Real force are same in every frame.

Q.18 (D)

Sol.3 4L LK

T L

1K T

Q.19 (C)

Sol.

x

ucos tdisp.V ucost t

Q.20 (B)

Sol.

i i f f

2

2 2

U K U Km b L 1b sin g 0 m sin g mVL 2 2 2

gsinV L bL

Q.21 (B)

Sol. 2

2

2

x at ,y bty ayt x parabolab b

Q.22 (B)

Sol. Finally system will move with common velocity = v

From conservation of linear momentum

5 4 5V 15V V 1m / s

Heat = loss in Kinetic energy

i

2f

1K 5 16 40J21K (5 15) 1 10J2

Loss 30J

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Q.23 (C)

Sol. 2dU d 1 dxkx Kxdt dt 2 dt

40 0.1 (3 1)16J / s

Q.24 (B)

Sol.A B

2T TT

1010

a 3a

2

2B

3T 10 a, 10 T 3a a 2m / s1S 3 2 1 3m2

Q.25 (C)

Sol. From diagram

o

22

22

d 1 tan45 1dt v

1 dv dv1 vv dt dt

dv 1 1m / sdt 33

Q.26 (A)

Sol.

60o 30oRV

2RV 25

2

R3V2

R3V2

VR

VRM

Now

o R

R

R

V 3 / 2 1tan30 V 3252

V 25m / s

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Q.27 (C)

Sol.

2 2

W K1 1m a 0 ma2 2

l l

Q.28 (C)

Sol.

(3,4) y= 4/3xy

x

3

0

4W ydx xdx 6J3

Q.29 (A)

Sol. P = kt

2 2

dvm V ktdt

kVdv tdtm,

kv tm

Q.30 (D)

Sol. 1 x y z

x 2 2 y z

L M E TM (ML T ) T

x y 0 solving1 12y 1 x , y , z 1

2 22y z 0

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CHEMISTRYQ.31 (B)

Sol.2 2

2 2

1 4 1 9 32 2725 3.5RZ 3 RZ 8 24

135 1281 9 1 16 7 1120RZ 8 RZ 15

Q.32 (A)

Sol.2 2

22 3

2

2 4

zz z v znK.E 13.6eV , ,

nh n 2 r nz

K(ze)e zF (I,II,IV)r n

Q.33 (A)

Sol.

0

h h hmv 2mKE hc hc2m

Q.34 (C)

Sol. 2 22n 2 3 18

Q.35 (D)

Sol. 3-radial nodes, yz-plane, origin (6 dyz) (n – l – 1) = 3

Q.36 (B)

Sol. 3 Px has 1 radial and 1 angular node.

Q.37 (B)

Sol. 34 66.663 1.5

3 100 256

Q.38 (D)

Sol.

740 100 1.146 0.0821 300100 x760 x

28 32x 72.42%

Q.39 (C)

Sol. 2 3 3

2 3 3

3

2.222.22 mg CaCI 100mg CaCO 2mg CaCO111

1.919mg MgCI 100mg CaCO 2mg CaCO95

4mg CaCO in 1L 4ppm

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Q.40 (A)

Sol. 1 L H2O2 solution — 33.6 L of O2 at STP

500 mL of H2O2 solution — 16.8 L of O2 at STP

50 % loss 8.4 L of O2 at STP

moles of O2 =

3 0.0821 3008.4 3 8, L57022.4 8760

Q.41 (C) Q.42 (A) Q.43 (D) Q.44 (A)

Sol. 4.925 g (CuCI2 + Cu Br2) (134.5x + 223.5 y = 4.925)

x mole y mole

5.74g AgCl Br AgBr CI5.74AgCI 2y

143.55.74 5.742y 2y 2y 143.5 2y 188 6.63

143.5 143.5y ??, x ??

(a) 2y 223.5% CuBr 100%

4.925

(b) x y 63.55% Cu 100%

4.925

(b) 2y 100%

5.74143.5

(d) (2x + 2y)

Q.45 (C)

Q.46 (C)Sol. AI – O & O – H bonds are not equal in energy.

However, AI(OH)3 behaves Amphoteric.

Q.47 (C)

Sol. (i) 2 3Na ,Mg ,AI size decreasing2 3I ,S ,N decreasing size in aqueous state.

2O,O ,O decreasing order of electron Affinity..

2IE N,F,O increasing order of (IE)2

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Q.48 (C)

Sol.

CHOCHO

OHCCHO

O O

O

(1)

(1)

(2)

(2)

(3)

(3)

(4)

Q.49 (C)

Sol. (a) (b) NOH

:

(c) N

OH

:

(d) NOH

:

Q.50 (C)

Sol.

Q.51 (D)

Sol.

Q.52 (B)

Sol. Angle of rotation mass concentration.

For 1 L solution angle of rotation = o o200mL 20g30 620g 1000mL

lc

= specific angle of rotation at fixed temperature ( ) and fixed wave length ( ) = angle through which PPL is rotated.c = mass concentration (g/mL)l = length (dm)

Substituiting values

o

o 1 16 30 mLg dm20g 10dm

1000mL

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Q.53 (B)

Sol.CH3

CH3

CH3

CH3

H

H

II

Bulky groups are on anti position.

Q.54 (C)

Q.55 (C)

Sol. gauche conformation

Q.56 (D)

Sol. C CHH

CH3CH3

OHOHC C

HH

** If the stereochemistry about the double bond in X is cis, the number

of enantiomers possible for X is 2

Q.57 (C) 1 2 3 4

Sol. CH3---CH

OH

---CH

CH3

---CH3 3-Methyl-2-butanol

— OH is functional group.

Q.58 (C)

Sol.

O

CCI Benzene carbonyl chloride

Q.59 (A)

Sol. ---SO3H, ---COOH, ---CONH2, ---CHO

Q.60 (B) OH

CNBr

1

23

45

— CN is most prior functional group.Hence, 2-Bromo-5-hydroxybenzonitrile

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MATHEMATICSQ.61 (D)

Sol. We can write sin x sinx lnsin x(sin x) e

now maximize & minimize sinx ln sin x

Q.62 (A)

Sol. From given condition we can obtain x ytan 72

now 2

x y2tan72sin(x y) x y 251 tan

2

Q.63 (C)Sol. Graphically

0 23

45

6x

hence upto 12 total no. of intersection is 10 so no. of solution is 10

Q.64 (A)

Sol. 7 4 7cos 1 sin 0 butcos 1

so cos 1; sin 0

0, 2

Q.65 (C)Sol.

Above expression can be written aso o o o

o o(cos 1 sin 1 ) (cos2 sin2 ) ................

cos 1 cos 2

o o

ocos 45 sin 45

cos 45

now convert numrator in term of complete sin

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Q.66 (C)

Sol.2012 1006 1006

2 4 20102

1 (1 x ) (1 x ) (1 x )1 x x .......x1 x (1 x) (1 x)

503 503

1006 (1 x ) (1 x )(1 x )(1 x) (1 x)

1006 2 502 2 2 502(1 x ) (1 x x .......x ) (1 x x x .....x )

this is divisible by 2 n 11 x x .....x if n 1 502

n 503

Q.67. (C)

Sol. above expression can we writen as logb loga clog a log b

now use A.M G.M

Q.68 (C)Sol. Check by option

Q.69 (A)

Sol. Let P denote the desired product, and letQ sina sin2a sin3a.....sin999a .

Then9992 PQ (2 sina cos a) (2 sin2a cos2a).....(2 sin999a cos999a)

sin2a sin4a.....sin1998a

(sin2a sin 4a....sin998a) [ sin(2 1000a)]

[ sin(2 1002 a)].....[ sin(2 1998a)]

sin2a sin4a.....sin998a sin999a sin997a....sina Q

It is easy to see that Q 0 . Hence the desired product is 9991P

2 .

Q.70 (A)Sol. o o o2 sin2 4 sin4 ..... 178sin178 ,

which is equivalent too o o o o o

o2 sin2 sin1 2(2 sin4 sin1 ) ..... 89(2 sin178 sin1 )

sin 1

.Note that

o o o o2 sin 2k sin1 cos(2k 1) cos(2k 1) .We have

o o o o o o

o2 sin2 sin1 2 (2 sin4 sin1 ) ..... 89(2 sin178 sin1 )

sin 1

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o o o o o o

o(cos1 cos3 ) 2 (cos3 cos5 ) ..... 89(cos177 cos179 )

sin 1

o o o o

ocos1 cos3 .... cos177 89 cos179

sin 1

o o o o o o

ocos 1 (cos3 cos177 ) ..... (cos 89 cos91 ) 89 cos1

sin 1

o o

ocos 1 89 cos 1

sin 1

= o90cot 1 hence average is ocot 1 .

Q.71 (D)Sol. | sin x| is periodic with period , while {x} is periodic with period 1

no common period is possibleQ.72 (C)

Sol. f(x) is odd if 2p0 1

x 1

p (0, 25)Q.73 (C)

Sol.2

2

1x 1 x5x2

22

1 15x 1 x x3

x

y

O 53

53

(0, 1)

2

1x 1 x

hence in positive region two curve are non intersecting

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Q.74 (A)Sol. sin(A B) sin A cosB cos A sinB

3 31 1( sin B sinB) cosB (cos B cosB)sinB2 2

1 sin2B2 2

....(3) (Verify)

By 2 2(1) (2) , we have

6 6 2 2 4 42 cos B sin B cos B sin B 2 (cos B sin B)

2 2 3 2 2 2 2 2 2(cos B sin B) 3 cos B sin B(cos B sin B) 1 2 cos B sin B

2 21 3 cos B sin B 1 2cos2B

230 sin 2B 2cos2B

4 2 28 cos 2B 3sin 2B 3(1 cos 2B)

1cos 2B (Verify)3

2 2sin 2B3

1sin (A B) from (3)3

Q.75 (C)

Sol. above experssion can be written as

1 1 1 1f(x) ...........x x 1 (x 1) (x 2)

1 1(x n 1) (x n)

on simplifying we get

nf(x)x(x n)

1 x(x n)f(x) n

x( x n) n

n

2 2x nx n 0

| | 5 n

Q.76 (B)

Soln. f(x) can be written as 5f(x)

13 sin (x )

whre 1 12tan5

5f(x)

13 cosec (x )

5| f(x) |

13

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Q.77 (D)

Soln. 20 x 1 | x | 1

But 2x 1 | x | 1

if x 0 but x 0 is not domain of cot(sinx)

20 x 1 | x | 1

2x 1 | x | 0

Hence 2

1

x 1 | x |

is not defined

hence x

Q.78 (D)

Soln. f(x) 2 sin x4

114

2

y

x/ 4

5 / 4

hence f(x) is one - one but not onto so 1f (x) not existQ.79 (C)

Sol. 31log kx

, k

31log kx

kx 3

possible values of k are 1, 0, 1, 2, 3,.......

2 31 1 1S (3 1) ......3 3 3

(1/ 3) 1 94 4

1 (1/ 3) 2 2

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Q.80 (A)Sol. Given tan x cos x

or 2 2sin x cos x 1 sin x

now, 21 sin xcosec x sinx 1

sinx

(from (1)) ]

Q.81 (A)

Sol. Let 2f(x) sin x b now compare the coefficient and eliminate b. divide by 2cos

to get (tan 1) (tan 2) 0 4

or 1tan (2) ]

Q.82 (A)

Sol. We know that 1 cos Acot A / 2

sinA

o o

o1 1 cos165cot 82 6 2 3 22 sin165

now 6, k 2

as be know G.C.D (a, b) L.C.M (a, b) (a b)

hence answer is (A)

Q.83 (D)Sol. Make sign scheme of above expression

0 1 2 3 4

+++

x [1, 3] (4, )

Q.84 (A)

Sol. Make graph of [x] { x }

0 1 2 [x] {x}

0 1 2

hence range is [0, )

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Q.85 (B)

Sol. On solving given equation be get 2sin x3

all these values are repeated four times in [0, 2 )hence number of principle solution is 4

Q.86 (A)Sol. both equation are satisfied in fourth quadrants

/ 4

hence general solution is 2n , n z4

Q.87 (D)

Sol. If any one of A B C is obtuse angle then that sum may be negativehence answere is (D)

Q.88 (C)Sol. Use A. M H.M

Q.89 (C)Sol. Graphically

8

17 2 3

2

hence number of solution is 1

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IITian’s TAPASYA

Q.90 (C)Sol. On simplyfying 3sin x sin 3x

3sinx sin3x sin 3x

4

23 1sinx sin 3x sin 3x4 4

3 [cos 2x cos 4x]8

18

(1 cos6x)

1 3 3 1cos 2x cos 4x cos 6x8 8 8 8

on comparing L.H.S & R.H.S we get 01c

8

, 61c8

, 23c8

, 43c8

0 6 2 4| c c | |c c | 0