1
FIITJEE
JEE(Advanced)-2015 ANSWERS, HINTS & SOLUTIONS FULL TEST– V (Paper-1)
Q. No.
ALL INDIA TEST SERIES
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AITS-FT-V-(Paper-1) –PCM(Sol)-JEE(Advanced)/15
1.
PHYSICS A
CHEMISTRY B
MATHEMATICS B
2.
A
C
A
3.
D
B
C
4.
B
A
D
5.
A
B
C
6.
B
A
C
7.
A
C
B
8.
C
A
D
A, C
B, C
A, C
A, D
B, C
A, D
A, B, C, D
A, C
A, B, D
A, B, C
C, D
13.
C
D
B
14.
C
A
A
15.
B
C
D
16.
D
A
D
17.
A
A
C
18.
C
B
B
1.
3
2
8
2.
2
4
4
3.
6
0
4
4.
6
1
6
5.
2
4
1
9. 10. 11. 12.
B, C
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2 AITS-FT-V-(Paper-1)–PCM(Sol)-JEE(Advanced)/15
Physics
PART – I SECTION – A
1.
2.
m1v1 m 2 v 2 1m / s m1 m2 At maximum extension both blocks will move in same direction with VCM now use energy y conservation. VCM
M 2 2 12 F – N = Ma N = Ma1 M 2 N 1 2 12 Acceleration of hinge O
F N
a1 1 N N
a1 1 2 2 Nx = – F/4 a = 5F/4M and = 9F/2M
=
a
F
a
F ao a ˆi ˆi 2 M 9 L 4
3.
y y0 sin kx cos t and
4.
d KA T1 T2 equation of heat flow through the box. dt L
5.
Just after collision. a b v e ucos L2 m2 v ucos a b m1 a2 12
6. 7.
u sin v
1 2 2 L constant 2 2C Using COM; vcos = u sin 2v sin and e 2 tan2 ucos 2tan2 < 1
u v
v
1 tan < 1/2 tan1 2
8.
Power factor = VRMS RMS cos
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3 AITS-FT-V-(Paper-1) –PCM(Sol)-JEE(Advanced)/15
9. 10. 11. 12.
np p for minima y 2n 1 d 2d y y A sin t kx A cos t kx t C Vmedium
For maxima y
Isothermal PV cons tan t adiabatic PV r constant
13-14. h eV0 15-16. E mc 2 17-18. f
C V0 f0 C VS
SECTION – C 1.
3 2 km/hr
2.
The centre of mass of system will not move horizontally.
3.
F URel
4.
In steady state the current in branch containing capacitor will become zero.
5.
F q E V B
dM dt
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4 AITS-FT-V-(Paper-1)–PCM(Sol)-JEE(Advanced)/15
Chemistry
PART – II SECTION – A
1
1.
1
3
NH2OH H N2 O 2NH4 2H 3H3O
S
2.
P S S S
S
P
P
S
S
S
S
P Has 3 p - d P – S bond Has 3 P = S bonds Has 3 tetrahedral units of P Has 6 P – S – P linkages. 3.
KI 2KMnO4 H2O KIO3 2KOH MnO2 (nf = 6) (nf = 3) Moles of KI × 6 = 3 × 0.2 × 10 × 10-3 Moles of KI = 10-3 = 1 milli mole = x
S C N I2 H SO42 HCN I H2O
To produce 10-3 moles I ,
Moles of S CN 6 10 3 1 10 3 Moles S CN 1.6 10 4 moles 6 4.
O
CH3
OH CH3OH
H H2 O
OH
Tautomerises
H 5 C6 C
H
O
O C6H5 CHO
OH
A
N2H4 / OH
OH H 5C 6 C
H
D 2 enantiomeric pairs possible for (D).
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5 AITS-FT-V-(Paper-1) –PCM(Sol)-JEE(Advanced)/15
5.
CoCl2 2KCN Co CN2 2KCl Buff coloured Co CN 2 4KCN K 4 Co CN 6
6.
o
L.H.S.
Half cell H2 2H 2e
Reaction E Eoxo 0.00 V
R.H.S.
Zn2 2e Zn
Eored 0.76 V
Net zn2 H2 Zn 2H , Eocell 0.76 V 2
H 0.0591 K 2 log K Zn n o Ecell Ecell
0.0591 log K n
0.0591 log10 H 0.46 0.76 2 0.3 6 H 4.60 10 M
HSO3
0.4 M
2
H
4.6 10 6
SO32 6.4 10 3
H SO23 4.6 10 6 6.4 103 Ka 7.3 108 HSO3 0.4 pKa = 7.13
7.
O
O C
OMe
MeOH
O
NMe
Cl O
O OMe
MeNH
2
OH O
O OMe
PCl
3
C O
O
NHMe O
O
1 1 1 RH 2 1 R H 1 1
8.
Shortest of Lyman series 1 for H-atom
9.
(2) B OH3 NaOH NaBO2 Na B OH 4 H2O can be made to proceed forward by
adding cis-diol to stabilization by chelation. (3) The solution turning milky on passing H2S through group II solution indicates the presence of oxidizing agent where H2S is oxidised to 8O2. 10.
(A) The heat of formation for NO2 is calculated as – 45 kJ mol-1. (B) For reaction N2 2O2 2NO2 , H 310 kJ / mole. i.e. it is exothermic. 1 1 N2 O2 NO, Ho 55 kJ / mol 2 2 1 (D) NO O2 NO2 , Ho 100 kJ / mol, it is exothermic. 2
(C)
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6 AITS-FT-V-(Paper-1)–PCM(Sol)-JEE(Advanced)/15
11.
(A) No H-bonding can occur in chlorobenzene, so +I effect increases acidic strength. (B) Due to both steric and polar effect has no ortho effect is observed in case of o-MeOC6H4NH2. MeOC6H5NH2. p-MeOC6H4NH2 > o-MeOC6H4NH2 > m-MeOC6H4NH2 pKa = 5.24 (pKa = 4.45) (pKa = 4.2) N N >
NH2 >
(C)
N
pKa = 4.63
pKa = 5.25
pKa = 1.3
NH > (CH3 CH2) 2NH
(D)
12.
Pyrrolidine (pKa = 11.27)
(pKa = 10.98)
(A) is correct, S sys nRn
V2 , V 2 > V 1. V1
S sys ve
(B) PV = constant, as is high, slope is higher. (D) At boiling point, the process is at equilibrium G 0 . 14.
x = 6, y = 3, z = 2 Solution for the Q. No. 13 & 14. IO3 6OH Cl2 IO65 3H2O 2Cl
H IO56 H5IO6 o
o
100 C 200 C 2H5IO6 2HIO 4 I2O5 . 4H2O
17.
V. D. = 28.75 Dd 0.6 n 1 d 2NO2 At equilibrium : 1 0.6 1.2 N2O 4
0.4
PN2O 4 PNO2
0.4 1.2
If moles of N2O4 escaping out is x, then for NO2 it is (1 – x) x 0.4 46 x 0.188 1 x 1.2 92 XN2O4 escaping out 0.188, XNO2 escaping out 0.812 2
18.
1.2 PNO2 1.6 KP 2.2 PN2O4 0.4 1.6 KP does not change.
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7 AITS-FT-V-(Paper-1) –PCM(Sol)-JEE(Advanced)/15
SECTION – C 1.
Cl
Cl
Cl As
As Cl
Cl
Cl Cl
Cl
2.
H CrO C H N
OH ArO
3 5 5 2 B CH2Cl2
Collins reagent
O
O ArO
O
O O
CN
3.
CN
copolymerisation nCH2 CH CH CH2 nCH2 CH
CH2 CH CH CH2 CH2 CH
n
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8 AITS-FT-V-(Paper-1)–PCM(Sol)-JEE(Advanced)/15
Mathematics
PART – III SECTION – A
1.
If [x3 + x2 + x + 1] = [x 3 + x2 + 1] + x, then x is integer log |[x]| = 2 – |[x]| has same solutions as log |x| = 2 – |x|, x is integer No integral solution 0
2.
Each element has 5 choices, as it may be in any one of A1, A2, A3, A4 or may not be in any one The required number of ways = 57
3.
(1 + x)n = C0 + C1x + C2x2 ..... Cnxn
1 x n 1 1 n1
C0 x
C1x 2 C2 x3 C x n 1 ..... n 2 3 n 1
n2
1 x C x 2 C x3 Cn xn2 x 1 0 1 ..... n 1n 2 n 1 n 1n 2 2 1 3 2 n 1n 2
Put x = 2, we get
C0 2 C1 22 Cn 2n1 1 1 3n 2 ..... 2 23 n 1n 2 n 1 2 n 1n 2 2 n 1n 2
Sn
C 22 C1 23 Cn 2n2 3n 2 1 2 0 ..... 23 n 1n 2 n 1 2 1 n 1n 2
3n 2 2 n 1n 2
S7 3 9 2 7 8 7 S 6 2 8 9 38 3
4.
It is given that |z| = 1 z = cos + i sin (let), (0, 2) z z Now, 1 gives 2 |cos 2| = 1 z z 1 1 cos2 , 2 2 5 7 11 2 4 5 , , , , , , , i.e. 8 values 6 6 6 6 3 3 3 3
5.
As cot – tan = 2 cot 2 tan = cot – 2 cot 2 1 1 1 tan tan cot cot 2 2 4 4 4 4
6.
Latus rectum, 4a 2 2 1 a 2 1 1 Vertex = , 2 2 Axis = x – y = 0 As origin lies outside the parabola Focus = (1, 1), Directrix = x + y = 0 FIITJEE Ltd., FIITJEE House, 29-A, Kalu Sarai, Sarvapriya Vihar, New Delhi -110016, Ph 46106000, 26569493, Fax 26513942 website: www.fiitjee.com
9 AITS-FT-V-(Paper-1) –PCM(Sol)-JEE(Advanced)/15
Equation of parabola is
xy
2
2 x2 + y2 – 2xy – 4x – 4y + 4 = 0
2
x 1 y 1
2
7.
Tangent at (0, 0) will be same (3 + sin B)x + (2 cos )y = 0 and 2 cos x + 2cy = 0 are same 2cos2 c cmax = 1 where sin = –1 and = 0 3 sin
8.
Consider g(x) = xf(x) g is continuous on [0, 1] and differentiable on (0, 1) f(1) = 0 g(0) = 0 = g(1) By Rolles’ Theorem g(c) = 0 some for c (0, 1) cf(c) + f(c) = 0
9.
At x = 2, RHD = 5 + |1 – x| = 5 + 1 = 6 whereas LHD = 5
11.
Let the coordinates of point A are (ct, c/t) So, the slope of normal at A will be t2. And normal will be parallel to BC. So, t will be 2 c = 2.
12.
‘a’ must be negative and x2 – a = x should have no solution 1 Now, D < 0 1 + 4a < 0 a 4
y=x 0
13.
ABC b PQR a
ABC
14.
b 3 3 2 3 3 a ab a 4 4
Slope of OP and OQ will be
am1 am2 and respectively b b
a m1 m2 ab m1 m2 If POQ = than tan = b 2 2 a b a2m1m2 1 2 m1m2 b
Now, area of sector OPQ of circle x 2 + y2 = a2 = Area of sector OAB =
a2 1 a2 2 2
ab m m2 b1 2 1 a ab where = tan1 2 12 a 2 2 b a m1m2
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10 AITS-FT-V-(Paper-1)–PCM(Sol)-JEE(Advanced)/15
15.-16. LCM = 90º and CL = CM CLM = CML = 4 Let ACB = 2 3 LAC = and LCB = 4 4 By sine Rule in ABC 3 a2 + b2 = 4R 2 sin2 sin2 4 4 a2 + b2 = 4R 2 sin2 cos2 = 4R2 4 4 Let ADC = ABC = – CBM = 4 CAD = 2 4 BAC = CAD BC = CD 17.-18. We want to have an = k if
k k 1 2
n
n is an integer, this is equivalent to
A 4
L
4 B
D
C
4 M
k k 1
2 k k 1 2
k k 1 1 1 n 8 2 8
1 1 2n k 2 k 4 4 1 1 1 k 2n k k 2n k 1 2 2 2 1 Hence, an 2n = 2 = 2
k2 k
17.
Now, a = 2, b = 3, c = 5 Let A = number of numbers which are divisible by 2 B = number of numbers which are divisible by 3 C = number of numbers which are divisible by 5 Required number = A + B + C – A B – B C – C A + A B C 1000 1000 1000 1000 1000 1000 1000 = 734 2 3 5 6 15 10 30
18.
a = 2, b = 3, c = 5, d = 7 Hence, the given number is 25 · 35 · 53 · 73 4n + 1 is odd number therefore the factor 2 will not occur in divisor. 3 and 7 are of 4n + 3 form, odd powers of 3 and 7 will be of 4n + 3 form and even powers will be 4n + 1 form 5 is 4n + 1 form and any power of 5 will be of 4n + 1 form Number of divisors of 4n + 1 type = number of terms in the product (1 + 32 + 34)(1 + 5 + 52 + 53)(1 + 72) 2 5 2 3 3 + number of terms in the product (3 + 3 + 3 )(1 + 5 + 5 + 5 )(7 + 7 ) = 48
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11 AITS-FT-V-(Paper-1) –PCM(Sol)-JEE(Advanced)/15
SECTION – C 1.
As g(x) is inverse of f(x) Domain of g(x) is range of f(x) a = 3, b = 11
2.
Required number of ways = co-efficient of x30 in (x2 + x3 + x4 + x5 + x6 + x7 + x8)5
5
x 2 1 x7 = co-efficient of x in 1 x 20 7 5 –5 = co-efficient of x in (1 – x ) (1 – x) 24 17 10 = C20 – 5 C13 + 10 C6 = 826 A = 8, B = 2, C = 6 A+B–C=4 30
3.
x3 1 1
2
For x [0, 2] 1 f(x) = 2
x3 1 3
2
=
x3 1 1
x3 1 3
x3 1 3
2
f x dx 4 0
4.
Orthocentre is foot of perpendicular drawn from origin on the plane
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