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XII Part Test-8 Page # 1
Q.1 Thecorrect outputfor the given circuit is
B
A
C t2T0T0
A B 2T0
(A) (B) T0
(C) 2T0 (D)
[Semiconductor / Tough]
Q.2 If 10,000 volts are applied across onX ray tubes find the ratio of wavelength ofthe incident electrons
and the shortest wavelength of X ray coming out of the X ray tube, given e / m of electron
= 1.8 1011 C.kg1.(A) 1 : 10 (B) 10 : 1 (C) 5 : 1 (D) 1 : 5
[X-Rasy / Easy]
Q.3 Whena certainmetallicsurfaceisirradiatedwithmonochromaticlightwavelength,thestoppingpotential
for photoelectric current is 3 V0. When the same surface is irradiated with light of wavelength 2 ,the
stopping potential is V0. The threshold wavelengthfor thegiven surface is
(A) 4 (B) 6 (C) 8 (D) 4/ 3
[PEE / Moderate]
Q.4 Statement 1: Nuclear fusion reactions for nucleiofsmall atomic mass (A< 20) can takeplaceonlyat
hightemperatures.
Statement 2: Nuclear fusionreactions for nuclei of small atomic mass (A < 20)are exothermic.
(A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1.
(B) Statement-1istrue,statement-2istrue and statement-2isNOTthecorrectexplanationforstatement-1.
(C) Statement-1 is true, statement-2 is false.
(D)Statement-1 is false, statement-2 is true.[Nuclear / Easy]
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XII Part Test-8 Page # 2
Q.5 An LC circuit contains inductance L = 1H and capacitance C = 0.01F. The wavelength of
electromagneticwave generatedis nearly
(A) 0.5 m (B) 5 m (C) 190 m (D) 30 m
[EM Waves / Moderate]
Q.6 A pnjunctiongermanium diode isshown here. Thecurrent inexcessof10mAthrough the diode produces
a large Joule-heating which damages (burns) the diode. Ifwe want touse a 1.5V batteryto forward bias
the diode,whatshouldbethe value ofresistorusedinserieswith the diode,sothatthe maximum current
does not exceed 6mA ?
1.5V
(A) 100 (B) 200 (C) 300 (D) 400
[PN Junction / Moderate]
Q.7 For a p-n-p transistor, the C E input characterstic curves are shown in figure for different voltages of
Vc e
then:
v1 v2v3
Ib
vbe
(A) V1> V
2> V
3 (B) V
3> V
2> V
1 (C) V
1= V
2= V
3 (D)none
[Semiconductor / Easy]
Q.8 The ratio ofmagnetic moment tothe angular momentumis a universal constantfor hydrogenlike atoms
and ions. The value ofthisconstant is
(A)m8
e0
2
(B) m2e (C)
e2m (D)
0
2
e2m
[Bohr / Moderate]
Q.9 A message signalof frequency m
is superposed on a carrierwave of frequency C
to get an amplitude
modulated wave (AM). The frequency of theAM wave will be
(A)m
(B) C
(C)2
mC (D)2
mC
[Communication / Easy]
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XII Part Test-8 Page # 3
Q.10 The refractiveindexfor matterwaves can bedefinedasu
cwherec is some constant. Sorefractive index
formatterwaves.
(A) is inverselyproportional to (B) is independent of
(C) is directlyproportional to (D) is proportional to
[Bhor / Easy]
Q.11 Abeam offastmoving -particleswas directedtowards a thin film ofgold. The partsA', B'and C'of the
transmitted and reflected beams corresponding to the incident partsA, B and C of the beamare shown
in theadjoining diagra. The numberof-particlesin
BA
C
B'
A'
C'
(A) B' will beminimumandin C'maximum (B)A'will bemaximum and inB' minimum
(C)A' willbeminimum and inC'maximum (D) C'willbeminimumandin B' maximum
[Nuclear / Easy]
Q.12 Lightofwavelength fallsonametalhavingworkfunction0
hc
.Photoelectriceffectwilltakeplaceonlyif:
(A) 0 (B) 20 (C) 0 (D)< 20
[PEE / Easy]
Q.13 In an NPN transistor circuit the collector current is 10 mA. If only90% of emitted electron reach the
collector, then
(A)IB = 2mA (B) IC = 1mA (C) IE = 11mA (D) IE =9mA[Semiconductor / Easy]
Q.14 Half lives of two isotopes X and Y of a material are known to be 2 109 years and 4 109 years
respectively. Ifa planet was formed with equal number of theseisotopes, estimate thecurrent age of the
planet, given thatcurrentlythe materialhas 20% of X and 80% of Yby number.
(A) 2 109 years (B) 4 109 years (C) 6 109 years (D) 8 109 years
[Radio / Tough]
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XII Part Test-8 Page # 4
Q.15 For what value of the quantum numbern will the de broglie wavelength of anelectron in the hydrogen
atombe4a0? {a
0= radius of electron in ground state}
(A) 1 (B) 2 (C) 3 (D) 4
[Bhor / Moderate]
Q.16 A certain radio nuclide starts getting produced at a constant rate = 104 s1by some mechanism at a
certain moment t = 0.At this moment, there are already 105
number of radio-nuclides present in thesample. The mean life of the radionuclide is 20 seconds.At t = 40sec, what will be dN/dt, rounded to
the nearest whole number? [Given that e2 =7.4]
(A) 375 /s (B) +676 /s (C) 676 /s (D) + 762 /s
[Radio / Tough]
Q.17 The K, L and M energy levels of platinum lie roughly at 78, 12, and 3 KeV respectively. The ratio of
wavelength of K linetothatofK line in X-ray spectrum is
(A) 322
(B)223
(C)2522
(D)2225
[X-Rasy / Moderate]
Q.18 A beam of 5 keV -particles and a beam of 5 keV electrons are absorbed bya target. The two beams
deliver equal amounts of energyto the target per second.
Ifelectronofmass
particleofmass = 7.27103, what is the value of
electrontoduetargetonpressure
particle-toduetargetonpressure?
(A) 1.38 104 (B) 1.17 102 (C) 1.45 (D) 85.3
[Bhor / Tough]
Q.19 If the potential difference applied acrossa Coolidgetube is increased :
(A)thewavelengthoftheK line will increase
(B) the wavelengthof the K linewilldecrease
(C)the difference in wavelengthbetween the K andK will decrease
(D) none of these[X-Rasy / Easy]
Q.20 Ina reverse biased p-n junction, almost no current flows because
(A)Electrons and holes recombine beforethey can cross the junction
(B) Onlyminoritycarriers,whose densitiesare verysmall,contribute to thecurrent, when they cross the
junction
(C) The electric field in the neutral regions is verysmall
(D)All theapplied voltage appears across theohmic contacts[Semiconductor / Easy]
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XII Part Test-8 Page # 5
Q.21 AnLEDismadefromsemiconductingmaterialhavinga bandgap of1.1eV. What typeof radiation does
theLED emit?
(A)Ultraviolet (B)Blue light (C)Redlight (D)Infrared
[PEE / Easy]
Q.22 The Davisson-Germer experiment that first demonstrated the wave nature of matter used electrons
acceleratedto 54V. Determine thewavelength of theelectronsin theDavisson-Germer experiment.(A) 1.67 (B) 1.21 (C) 3.45 (D) 5.21
[Bhor / Easy]
Q.23 ThehalflifePo-218is 3 minutes.Whatfractionofa 10gramsampleofPo-218will remainafter 15min?
(A) 1/32 (B) 1/64 (C) 1/25 (D) 1/15
[Radio / Moderate]
Q.24 A 1 KWsignalis transmitted using a communication channel which providesattenuation at the rate of2dB per km. If the communication channel has a total lengthof 5 km, the power of the signalreceived is
(A) 900 W. (B) 100 W. (C) 990 W. (D) 1010 W.
[Communication / Moderate]
Q.25 In Fig. assumingthe diodes to beideal,
(A)D1
is forward biased and D2
is reverse biased and hence current flows fromA to B
(B) D2is forward biased and D
1is reverse biased and hence no current flows from B toA and vice
versa.
(C)D1 andD2 are both forward biased and hence current flows fromA to B.(D)D
1andD
2are both reverse biased and hence no current flows fromA to B and vice versa.
[PN Juncation / Easy]
Q.26 A certain metal has a workfunction. If light of wavelength shines on this metal, thephotoelectrons
havea maximum kinetic energyK. Whatwillbetheir maximum kinetic energyif light ofwavelength2
shinesonthe metal ?
(A) (K +) / 2 (B) (K ) / 2 (C) 2K (D) K / 2
[PEE / Moderate]
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XII Part Test-8 Page # 6
Q.27 Fig.shows Zener diode witha break downvoltageof40V connectedto100 V D.C. source with a series
resistance RS
and a loadresistor (RL). Find the output voltage across R
L.
(A) 40V (B) 20V (C) 50V (D) 60V
[Semiconductor / Easy]
Q.28 The figure shows energy levels of a certain atom. When the ystem moves from level 2E to E, a
photon of wavelength is emitted. The wavelength of photon produced during its transition from
level 4/3E to E level is
(A) 3 (B) 3
4 (C)
4
(D) 2
[Bhor / Moderate]
Q.29 90% ofthe active nucleipresent ina radioactive sample are found to remain undecayedafter 1day. The
percentage of the undecayed nuclei leftafter two days willbe :
(A) 85% (B) 81% (C) 80% (D) 79%
[Radio / Moderate]
Q.30 In a photoelectric effect measurement the stopping potential for a given metal is found to beV0Volts
when radiationof wavelength 0 is used. Ifradiationof wavelength 20 isusedwithsamemetal,thenthe
stopping potential will be observed tobe (Where symbols havetheir usual meaning)
(A) V0 /2 (B) V0+ e2hc
(C) 2V0 (D)V0 e2hc
[PEE / Tough]
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XII Part Test-8 Page # 7
Q.31 The work done in adiabatic compression of 2 moles of ideal monoatomic gas against 2 atm
external pressure if initially temperature and pressure is 300 K and 1 atm.
(A) 360 cal (B) 720 cal (C) 800 cal (D) 1000 cal
[Thermodynamics\Easy]
Q.32 What will be the maximum amount of heat released, when 321gm of a mixture of Fe2O3and
Al is subjected to sparking in absence of air?
HfFe2O3= 199kJ/mole HfAl2O3= 399kJ/mole
(A) 200 kJ (B) 300 kJ (C) 400 kJ (D) 100 kJ
[Thermochemistry\Easy]
Q.33 What will be the value of resonance energy of N2O if
HBDE N = N = 400 kJ/mol ; o
fH N2O = 100 kJ mol1
HBDE N N = 950 kJ/mol ; HBD EN = O = 600 kJ mol1
HBDE O = O = 500 kJ/mol
(A) 200 kJ / mol (B) 150 kJ / mol (C) 100 kJ / mol (D) 50 kJ / mol
[Thermochemistry\Easy]
Q.34 '' for NH3including contribution from vibrational degree's of freedom is
(A)3
4(B)
9
10(C)
6
7(D)
12
13
[Thermodynamics\Easy]
Q.35 Total work done in given cyclic process is
(A) Greater than zero (B) Less than zero
P
1/V
(C) Equal to zero (D) Can't determine[Thermodynamics\Easy]
Q.36 For the real gas reaction,
2SO2(g) + O2(g) 2SO3(g) H = 440 kJ/mol
If the reaction is carried out in 10 litre rigid vessel the initial pressure is 50 bar which decreases
to 20 bar in the course of reaction. The change in internal energy for the reaction is
(A) 437 kJ (B) 410 kJ (C) 443 kJ (D) 470 kJ
[Thermodynamics\Easy]
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XII Part Test-8 Page # 8
Q.37 For the reaction,
2NH3 (g) N2(g)+ 3H2(g)Identify the statement which is not correct.
(A) o NHmo
Nmo
Nm 322 S2S3S
(B) Heat absorbed at constant pressure and temperature will be more as compared to heat
absorbed at constant volume.(C) reactantenergyBond > productenergyBond(D) The value ofG is expected to be negative at extremely low temperatures.
[Thermodynamics\Easy]
Q.38 Which of the following substances will have positive value ofHformation?
(A) Br2(l) (B) O3(g) (C) ZnO(s) (D) H+(aq)
[Thermochemistry\Easy]
Q.39 Which of the following option(s) will show a increase in Gibbs free energy?
(A) Combustion of propane at 1 bar and 500K.
(B) Vapourisation of any liquid at 1 atm and above its normal boiling point.
(C) Fusion of H2O at 1 atm and 0C if its normal melting point is 0C.
(D) Vapourisation of H2O at 100C and 1 bar if its normal boiling point is 100C.
[Thermodynamics\Easy]
Q.40 Which of the options contain correct set of parameters which are both amount and path
independent parameters.
(I) Internal energy
(II) Specific enthalpy
(III) Heat exchange at constant pressure condition
(IV) Molar heat exchange at constant volume condition
(V) Temperature
(VI) Work involved
(A) Only II, IV & V (B) All option except VI
(C) All options except III, IV & VI (D) Only II & V
[Thermodynamics\Easy]
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Q.46 Arrange in order of enolic content :
(a) (b)
(c) (d)
(A) c > d > b > a (B) d > c > a > b (C) a > c> d > b (D) b > c > a > d
[Isomerism/Easy]
Q.47 and are
(A) Chain isomers (B) Metamers (C) Positional isomers (D) Conformers
[Isomerism/Easy]
Q.48 Which of the following can not tautomerize?
(A)
O
O
(B) Ph C C Me
O O
(C)
O
OH
(D)
OO
[Isomerism/Easy]
Q.49 Which of the fiollowing can't show geometrical isomerism?
(A) CH3CH=NOH (B)
(C) C = NOH (D) HO N = N OH
[Isomerism/Easy]
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XII Part Test-8 Page # 11
Q.50 Molecular formula C4H6 can represent different compounds , one of them can not be
...............
(A) Alkyne (B) Diene
(C) Bicyclo compound (D) Spiro compound
[Isomerism/Medium]
Q.51 + HCNA + B
A & B are
(A) Meso compounds (B) diastereoisomers
(C) enantiomers (D) both A & B
[Isomerism/Medium]
Q.52 How many stereoisomer may have this naturaloccuring compound.
(A) 8 (B) 16
(C) 64 (D) 128
[Isomerism/Difficult]
Q.53 Which of the following is not the pair of diastereoisomers.
(A)
HH
HH
ClCl
ClCl
COOHCOOH
COOHCOOH
and
(B)H H
H H
CH3CH3 CH3
CH3
Me Me
Me Me
and
(C) and
(D)H H
H
HOH OH
OH
OH
Me Me
Me
Me
and
[Isomerism/Medium]
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XII Part Test-8 Page # 12
Q.54 Selectincorrectstatement :
(A) Resonance effects bond length
(B) trans-1-bromo-1,2-difluoro ethene and Z-1-bromo-1,2-difluoro ethene are geometrical isomers
(C) In CH2
O
O
COH
COH
most acidic H is connected directly to oxygen not on carbon.
(D) Boiling point ofOH
is less than
OH
OH[Resonance/Difficult]
Q.55 Selectcorrectstatement from the following.
(A)O
O is having very high resonance energy than
O
O
(B) CH3
COOH
is more acidic thanCOOH
(C) CH2
is more stable than OH.
(D) O
is more stable than OCMe||
O
[Resonance/Medium]
Q.56 Which of the following is/are correct.
(A) Order of heat of hydrogenation CC=CCCC=CC < CCC=CC=CCC
(B) Order of heat of combustion
(C) Order of stability of carbocation
N NN
(D) Order of heat of combustion cis-1,4-bis-(t-butyl) cyclohexane < Trans-1,4-bis-(t-butyl)
cyclohexane
[Hyperconjugation/Difficult]
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XII Part Test-8 Page # 13
Q.57 Which of the following reaction will not form aromatic ion.
(A) + aq. AgNO3 (B) + 2K
(C) + HBr (D) HBF4
[Hyperconjugation/Difficult]
Q.58 Which of the following orders is/areincorrect?
(A) Basic strengthN
>N
N
(B) Acidic strength
Cl|
COOHCHCH3 >Cl|
COOHCHCH 22
(C) Stability of carbocation
CH2
NO2
COOH|
COOH
[GOC/Difficult]
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XII Part Test-8 Page # 14
Q.59 Which of the following is correct order?
(A) Stability of carbocation
C H CH6 5 2 CH = CH CH2 2
(B) Acidic strength
COOH COOH
NO2
NO2
(C) Basic strength
NH2
NH
(D) Bond length (CN)
NH2 NH2
O
[Resonance/Difficult]
Q.60 Select theincorrectoptions.
(A) Stability of free radical
CH2
CH3 CH CH2 2>
(B) Stability of carbanion 232 HCCHHCCHCHC
(C) Stability order of carbocation 0) da
= 4, cb
= 9 then is equal to
(A) 2 (B) 3 (C) 6 (D) 36
[Vector / Easy]
Q.75 A 5 digit number divisible by 3 is to be formed using the numerals 0, 1, 2, 3, 4 & 5 without
repetition. The total number of ways this can be done is :
(A) 3125 (B) 600 (C) 240 (D) 216
[Permutations and Combinations / Difficult]
Q.76 Given a parallelogram ABCD. If |AB|
= a , |AD|
= b & |AC|
= c , then DB AB
. has the
value
(A)3
2
2 2 2a b c (B)
a b c2 2 23
2
(C)
a b c2 2 23
2
(D) none
[Vector / Difficult]
Q.77 If )kji(a
, )kji(b
, and c
are unit vectors perpendicular to the vectora
and
coplanar with a
and b
, then a unit vectord
perpendicular to both a
and c
is
(A) )kji2(6
1 (B) )kj(2
1 (C) )kj2i(6
1 (D) )kj(2
1
[Vector Algebra / Difficult]
Q.78 The number of ways in which 6 men and 6 women can dine at a round table if no two women
are to sit together is given by
(A) 6! 5! (B) 30 (B) 5! 4! (D) 7! 5!
[Permutation and Combination / Easy]
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XII Part Test-8 Page # 18
Q.79 The angle between the planes 3x 4y + 5z = 0 and 2x y 2z = 5 is
(A)3
(B)
2
(C)
6
(D) none of these
[ 3-D/ Easy]
Q.80 The equation of the plane containing the line31x
=
23y =
12z and the point (0, 7, 7)
is
(A) x + y + z = 1 (B) x + y + z = 2 (C) x + y + z = 0 (D) none of these
[ 3-D/ Moderate]
Q.81 Let P(3, 2, 6) be a point in space and Q be a point on the line )k5ji3()k2ji(r
.
Then the value of for which the vectorPQ is parallel to the plane x 4y + 3z = 1 is
(A)4
1(B)
4
1(C)
8
1(D)
8
1
[3-D/ Moderate]
Q.82 Equation of a plane which passes through the point of intersection of lines3
1x =
1
2y =
2
3z and
1
3x =
2
1y =
3
2z and at greatest distance from the origin is
(A) 7x + 2y + 4z = 54 (B) 4x + 3y + 5z = 50
(C) 3x + 4y + 5z = 49 (D) x + y + z = 12.
[ 3-D / Difficult]
Q.83 If the points (2 x, 2, 2), (2, 2 y, 2) (2, 2, 2 z) and (1, 1, 1) are coplanar, then
(A) 1z
1
y
1
x
1 (B) x + y + z = 1
(C) 11z
1
1y
1
1x
1
(D) none of these
[ 3D / Easy]
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XII Part Test-8 Page # 19
Q.84 Statement-1 : If vectors a
and c
are non-collinear then the lines
)ac2(ca6r
and )c3a(car
are coplanar
Statement-2 : There existandsuch that the two values of r
become same.
(A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for
statement-1.
(B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation
for statement-1.
(C) Statement-1 is true, statement-2 is false.
(D) Statement-1 is false, statement-2 is true.
[Vector / Easy]
Q.85 If )ba(c)ac(b)cb(ad
, then
(A) d
is a unit vector (B) cbad
(C) 0d
(D) c,b,a
and d
are coplanar..
[Vector Algebra / Easy]
Q. 86 If
a b c = 0 ,
a = 3 ,
b = 5 ,
c = 7 , then the angle between
a b& is :
(A) 6 (B) 32 (C) 35 (D) 3
[Vector / Moderate]
Q.87 The number of ways in which we can get a score of 11 by throwing three dice is
(A) 18 (B) 27 (C) 45 (D) 56
[Permutations and Combinations /Moderate]
Q.88 Vector equation of the line 6x 2 = 3y + 1 = 2z 2 is
(A) r = )ki(kji (B) r =
kj
3
1i
3
1k3j2i
(C) r = k3j2ikj3
1i
3
1 (D) r = k2j3i6k2ji2
whereis a parameter
[3-D / Moderate]
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XII Part Test-8 Page # 20
Q.89 Statement-1 :A student is allowed to select at most n books from a collection of (2n + 1)
books. If the total number of ways in which he can select at least one book is
255, then n = 3.
Because
Statement-2 :
01n2
+
11n2
+ +
n1n2
= 4n
(A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1.
(B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation for
statement-1.
(C) Statement-1 is true, statement-2 is false.
(D) Statement-1 is false, statement-2 is true.
[Permutations and Combinations / Difficult]
Q.90 Consider the planesP
1: x y + z = 1
P2: x + y z = 1
P3: x 3y + 3z = 2
Let L1, L
2, L
3be the lines of intersection of the planes P
2and P
3, P
3and P
1, and P
1and P
2
respectively.
Statement-1 : At least two of the lines L1, L2and L3are non-parallel.
Statement-2 : The three planes do not have a common point.
(A) Statement-1 is true, statement-2 is true and statement-2 is correct explanation forstatement-1.
(B) Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation
for statement-1.
(C) Statement-1 is true, statement-2 is false.
(D) Statement-1 is false, statement-2 is true.
[3-D / Moderate]
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XII Part Test-8 Page # 21
ANSWERKEY
PHYSICS
Q.1 D
Q.2 A
Q.3 A
Q.4 BQ.5 C
Q.6 B
Q.7 A
Q.8 B
Q.9 B
Q.10 A
Q.11 B
Q.12 CQ.13 C
Q.14 D
Q.15 B
Q.16 B
Q.17 D
Q.18 D
Q.19 D
Q.20 BQ.21 D
Q.22 A
Q.23 A
Q.24 B
Q.25 B
Q.26 B
Q.27 A
Q.28 AQ.29 B
Q.30 D
MATHEMATICS
Q.61 B
Q.62 D
Q.63 C
Q.64 AQ.65 A
Q.66 D
Q.67 C
Q.68 B
Q. 69 D
Q. 70 C
Q.71 C
Q.72 CQ.73 C
Q.74 C
Q.75 D
Q.76 A
Q.77 B
Q.78 A
Q.79 B
Q.80 CQ.81 A
Q.82 B
Q.83 A
Q.84 A
Q.85 C
Q.86 D
Q.87 B
Q.88 CQ. 89 D
Q.90 D
CHEMISTRY
Q.31 B
Q.32 B
Q.33 C
Q.34 BQ.35 B
Q.36 B
Q.37 D
Q.38 B
Q.39 C
Q.40 A
Q.41 B
Q.42 BQ.43 C
Q.44 D
Q.45 A
Q.46 A
Q.47 B
Q.48 A
Q.49 C
Q.50 DQ.51 B
Q.52 C
Q.53 B
Q.54 B
Q.55 B
Q.56 B
Q.57 C
Q.58 DQ.59 A
Q.60 C
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XII Part Test-8 Page # 22
SOLUTION
SOLUTION
Q.1 BA BA
B
CBBA
0 T0 C = )1.11( = 0
T0 2T
0 C = )1.11( = 0
2T0 C = )0.01( = 0
Q.2meV2
hc
photon
hceV
Q.3hc
= + c . (3v0) in case I
2hc
=+ c. v0 in case II
where0
hc
= (0 threshold wavelength)
Q.4 To overcome coulomb repulsion .
Q.5 =LC
1=
266 101010
1
= 107
f =2
107
= 7
8
10
103 2= 60
Q.6 The basic equationofdiode-circuit isRI + V
0= V
B
R =I
VV 0B
V =B 1.5V
V =RIR V0
R
Here VB= 1.5V, V
0= 0.3V, I = 5mA = 6 103A
R =6
102.1
106
3.05.1 3
3
= 0.2 103= 200
Q.7 InformationBased.
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XII Part Test-8 Page # 23
Q.8 Current I =
v
r2
e
magnetic moment= Ir2
angularmomentum=mvr
ratio =m2
e
Q.9 InformationBased.
Q.10 =u
c cv
c
Q.11 Numberof nucleus decreases as deviation angle increases.
Q.12hc
0
hc
0
Q.13 10% of IE= I
B
IB
=1mA I
E= I
C+ I
B= 10 + 1 = 11 mA
Q.14 Let total sum of number of isotopes at the formation of the planet was No and currently is N
Nx=
2
N0 t1e = 0.2 N ....(i)
Ny =
2N0 t2e
= 0.1 N ....(ii)
Dividingequation(ii)by(i)
t)( 21e
= 4
(12) t = ln 4
t4
1
2
1
10
2ln9
=2ln2
t = 8 109 years
Q.15 2R = n2n2 a
0= n n = 2
Q.16 Nrdt
dN
t
0
N
N
dtNr
dN
0
ln0Nr
Nr
= t
(r N) = (r N0)et
dt
dN= r N = (r N0) e
t = 20/t
54 e
20
1010
= 5000e2 = 5000/7.4 = + 676 per second Ans.
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XII Part Test-8 Page # 24
Q.171
hc
= 78 12 378
hc
2
= 2
1
=22
25
Q.18 If n particles each with mass m and speed v collide inelastically with the target per sec.
then rate of energy transfer = n .)E.K(nmv2
1 2
andRateofmomentumtransfer=nmv=n )KE(m2Since both beam transfer equal energy, n1 (KE)1 = n2 (KE)2 ,butKE1 = KE2 n1= n2
ratio of momentum transferred =222
111
)KE(m2n
)KE(m2n=
2
1
m
m= 7270
Q.19 K or K characteristics
Q.20 InformationBased
Q.21 =Ehc =
1.11240 nm ~ 1100 nm infra red.
Q.22 l =mv
h=
km2
h= 3119
34
101.9106.1542
1063.6
2
1mv2 = k
Q.23 15 min is 5 times of 3 min 5 half lite 1 fraction left=
32
L
2
1 5
Q.24 gain in dB = 10 log
t
0
P
P
Q.26hc
, K' = 2
hc=
2
K=
2
K
Q.28 2E E =
hc
3
E4 E =
hc
' = 3
Q.29 Decay in 1 day is 10% 1 decay in second day = 990100
10 1 nuclei left = 100 10 9 = 81.
Q.30 eV0= 0
hc
02
hc
'eV 00 2
hc
'VVe V' = V0= e2hc
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XII Part Test-8 Page # 25
SOLUTION
Q.31 For adiabatic irreversibleprocessnCv,m(T2 T1) = Pext(V2 V1)
= Pext
1
1
2
2
P
nRT
P
nRT
2 2
3R (T2 300) = 2
1
300R2
2
RT2 2
T2= 420KW =U = nCv,m(T2 T1)
= 2 2
3R (420 300)
= 720 cal
Q.32 Fe2O3+ 2Al Al2O3+ 2Fe (s)H = 399 + 199 = 200 kJH = 200 1.5 = 300 kJ
Q.33 N (g) + O (g)2 2 N O(g)22
1
2
1
H (N O,g)f 2
atoms
BDEN N BDEO=O+
(RE + BE + BE )N=N N=ON O2
Hf(N2O,g) = BDENN+ 21
BDEO=O [ ON2RE + BEN=N+ BEN=O]
100 kJ = 950 +2
1500 [ ON2RE + 400 + 600]
100 kJ = 1200 kJ ON2RE 1000
ON2RE = 100 kJ / mole
Q.34 Cv= RnR2
nR
2
nvib
rottr = R9R6R2
3R
2
3
Cp= 9R + R = 10R
= 910
C
C
V
P
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XII Part Test-8 Page # 26
Q.35 TCyclic process will be clockwise whenP plotted against V.Hence work done is negative.
P
VQ.36 For constant volume process
H =U + VP
U =H VP= 440 kJ 10 103 (20 50) 105 103 kJ= 410 kJ
Q.37 2NH3 (g)N2(g)+ 3H2(g)(1)Srxn> 0
Srxn= 0]S2[]3SS[ 3NH2H2N MMM
3NH2H2N MMM S22SS
(2)Process is endothermicH = +veng= 2H =U +ngRT
(3)Hrxn> 0
H = productofEBttanacReofEB > 0= productofEBttanacReofEB
(4) G =H TS
H,S = +veG < 0 at high temperature.
Q.38 Hformation of element in nature state is zero.Hfof O3 is endothermicHfof ZnO is exothermic & HfofH
+(aq) is zero.
Q.39 G =H TS(i) Combustion is spontaneous reaction so Hisveas H > TS(ii) G is ve for vaporisation above boiling point as TS > H
(iii) Gis+ve forfusionat0Cas H=+veand S=ve(iv)G is ve asS = +ve &H = +ve but TS >H
Q.40 II, IV& V are intensive and path independent properties. Internal energy, H depends on amount andw depends on amount as well as path dependent.
Q.41 (B) is incorrect
0Tqrev forall cyclic process.
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XII Part Test-8 Page # 27
Q.42 dS =T
PdVdTnC m,v
P
nR
T
P
V
S
T
Q.43 q = CT = 10 20 = 2000 J
U = q + wU = 2000 5 3 100 = 500 JH =U +(PV)= 500 + 10 100 = 1500 J
Q.44 = 80% =
2
12
T
TT
in[D] =85%whichismorethanreversible process it is not possible.
Q.45 (1) H =U +ngRTve ve + 0.5 RT
(2) H U +ngRT+ve = +1 +1 RT
(3) N2+ 3H2 2NH3x =U +ngRT
ve = ve ve(4) C2H4+ 3O22CO2+ 2H2O(l)
x =U +ngRTve = ve ) (3)
Q.46 With increase in acidity ofH and stabilityof enol formed its% contentincreases.
Q.47 Structures of given compound are MeOCH2Et and EtOCH2Me so metamers.
Q.49 Not required
Q.50 Molecular formula C4H6D. B. E. 2
Possibility 2bondor 1bond & 1 ringor 2 ring
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XII Part Test-8 Page # 28
Q.51 HCN +
ThusA& B are diastereoisomers.Ans:B
Q.52
Q.53 (A)
H
H
H
H
Cl
Cl
Cl
Cl
COOH
COOH
COOH
COOH
Cl
Cl
Cl
Cl
H
H
H
H
COOH
COOH
COOH
COOH
Diastereoisomers
(B) Chiral carbonis not present
(C) and Geometrical isomers are diastereoisomers.
(D)H
H
H
H
H
H
H
HO
HOH
OH
OH
OH
OH
OHOH
Me
Me
Me
Me
Me
Me
MeMe
H
HH
HHOOH
OHOH
Me
Me
Me
Me
Diastereoisomers]
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XII Part Test-8 Page # 29
Q.54 (A) Resonance effectbondlength
(B)C = C
F
Br
H
F
cis-1-bromo-1,2difluoro ethene
C = CF
BrF
H
Z-1-bromo-1, 2difluoro ethene
Identical
(C) CH2
COOH
COOH
most acidic (eq. R.S.)
(D)OH
B.P.
OH
OH
Q.55 (A) Ester group resonance wi th itself in a better way not to other so both have same resonanceenergy.
(B) Due to Ortho effect.(C) Negative onmore electronegative element ismorestable.(D) Equivalent R.S.are more stable thanunequivalent R.S.
Q.56 is less stable than so havinghigherheat of hydrogenation
Hence 'A' is incorrect. Heat of combustion of cyclo alkanes increases from cyclohexane (Higher No. of Catom) to cyclo
propane hence B is correct. Stabilityof Carbocation.
N N N
ResonanceStabilise
LessI effect
HigherI effect
> >+
++
Hence C is incorrect. Stabilityorderof disubstituted cyclohexane areis given as
H
H
H H
tBu
>
tBu
tBu tBu
So D is incorrect.
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XII Part Test-8 Page # 30
Q.57 (A) + aq. AgNO3 Ph
Ph
Ph
Ph
Aromatic
(B) + 2K
Aromatic
(C) + HBr
OH
Antiaromatic
(D) HBF4OH
OH
Aromatic
Q.58 (A)N
+ I,N
N
I of N
(B)
Cl|
COOHCHCH3 more (I),
Cl|
COOHCHCH 22 Less (I)
(C)
CH2
NO2
more (I),
CH2
CH3
more (+I),
(D)
COOH|
)CH(|
COOH
32 COOH|
COOHmore I.
Q.59 Stability ofcarbocation: C H CH6 5 2 CH = CH CH2 2
DancingResonance
Moredelocalisation
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Basic strength :
NH2
NH
5 RS 6 RSLess availablefor donation
Q.60 (A) Stability offreeradical :
CH2
CH3 CH CH2 2>
More delocalisation
(B)Stabilityof carbanion: 232 HCCHHCCHCHC
ve on more EN
More stable
(D)Stability of resonantingstructures :
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XII Part Test-8 Page # 32
SOLUTION
Q.61 The number of ways can be deduce as follows :
1 women and 4 men = 4C1 6C4= 60
2 women and 3 men = 4C2 6C3= 120
3 women and 2 men = 4C3 6C
2= 60
4 women and 1 men = 4C4 6C1= 6
Required number of ways = 60 + 120 + 60 + 6 = 246 Ans.
Q.62 Let, the required vector be= kdjdid 321 , where
51ddd 2322
21 , (given) .........(i)
Now, each of the given vectors c,b,a
is a unit vector
cos =|a||d|
ad
=|b||d|
bd
=|c||d|
cd
or ad
= bd
= cd
|d|
= 51 cancels out and |c||b||a|
= 1
Hence, 3
1
(d1 2d 2+ 2d3) = 4
1
( 4d1+ od2 3d 3) = d
d1 5d
2+ 2d
3= 0
and 4d1+ 5d
2+ 3d
3= 0
On solving,5
d
1
d
5
d 321
=(say)
Putting d1, d
2and d
3in (i), we get= 1
Hence, the required vectors are k5ji5 . Ans.
Q.63
432 3
100
3
100
3
100
3
100= 33 + 11 + 3 + 1 = 48. Ans.
Q.64 (Volume)2 = cba
cba
=
cccbca
bcbbba
ccabaa
=
12/12/1
2/112/12/12/11
=
2
1. Ans.Ans.
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XII Part Test-8 Page # 33
Q.65 Denoting a
, b
, c
by the given vectors respectively. These vectors will be collinear if there
is some constant K such that c
a
= K(b
a
)
a 60 = 20K and 55 = 11 K
a = 100 + 60 = 40
Q.66 5 + 8.9.5 = 365; 1st place is five + where 1st place is not five 75 |5
+5|
9|
8|
Q.67 ( a
+b
) (b
+ c
) = 3j (2i +4j ) = 6 k
Hence the required unit vector is k .
Q.68 Here, b)3y3x6(a)y12x3(p3
b)2y6x4(a)4x4y2(q2
On comparing, we get
3x + 12y = 2y 4x + 4 & 6x + 3y + 3 = 4x 6y 2
7x + 10y = 4 .........(i)
and 2x + 9y = 5 .........(ii)
On solving equations, we get x = 2, 1. Ans.
Q.69 cba
= 0
1434111
= 0 or 1 = 0 =1
Also |c|
= 3 1 +2 + 2 = 3 Ans.
Q.70 Since a
is perpendicular to d
, so x y + 2z = 0 (i)
Moreover , |b
| = | c
| so a
b
= a
c
as a
makes equal angles with b
and c
.
Thus xy 2yz + 3xz = 2xz + 3xy yz
xz 2xy yz = 0 (ii)
Also x2 + y2 + z2 = 12 (iii)
and y < 0, Substituting the value of y from (i) in (ii) we get x2 + 2xz + z2 = 0 so x = z
and y = z. Again substituting these value (iii) we get z2 = 4 i.e. z = 2 but y < 0 and y
= iz.
So z = 2 = y and x = 2
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XII Part Test-8 Page # 34
Q.71 Subtracting the first two equations we get y z = 4. From the third we get x + z = 3 which
are satisfied by (2, 5, 1).
Q.72 The total number of possible outcomes is 64.
The number of possible outcomes in which 2 does not appear on any die is 54.
Therefore, the number of possible outcomes in which atleast one die shows a 2 is
64
54
= 1296 625 = 671.
Q.73 Let A be the origin of reference and the position vector of B, C, D be d,c,b
, w.r.t. A. So
AB = b
, CD= cd
, AD = d
, BC= bc
, cAC
and bdBD
. The L.H.S. is equal
to )cd(b
. The R.H.S. is
222 |bd||c||bc||d|K
= bd2bbddccbc2bbccddK
= 2K )cd(b
.
Hence K =2
1
Q.74 We know that
)ba(
)dc(
= dbcbdaca
= 9
4 = 2 36.
since ba
and dc
are perpendicular so= 6. Ans.
Q.75 Reject 0 + reject 3 5! + 4 4! = 120 + 96 = 216
Q.76 To find
a b a . i.e.
a2
a b. (1)
now
a b c
a b2 2
+ 2
a b. =
c2 (2)
substitute the value of
a b. from (2) in (1) ]
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XII Part Test-8 Page # 35
Q.77 Let kzjyixc
. Since c,b,a
are coplanar,,
so
111
111
zyx
= 0 0 x 2y 2z = 0
Also c
is perpendicular to a
, so x + y z = 0.
Therefore1
z
1
y
2
x
and x2 + y2 + z2 = 1
( c
being a unit vector). We have x = 6
2, y =
6
1, z =
6
1.
Thus )kji2(6
1c
and
112111
kji
|ca|6
1ca
ca
1d
= )k
j
(2
1
)k
3j
3i
0(|ca|6
1
Q.78 No. of ways in which 6 men can be arranged at a round table = (6 1)! = 5! ways
Now women can be arranged in 6! ways
Total number of ways = 6! 5! Ans.
Q.79 = cos1
950
1046= cos1 (0) =
2
. Ans.
Q.80 The equation of plane containing the line
3
1x
=2
3y =
1
2z
is a(x + 1) + b(y 3) + c(z + 2) = 0 ... .. .. ..(1)
where 3a + 2b + c = 0 ..........(2)
This passes through (0, 7, 7)
a + 4b 5c = 0 ........(3)
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From equation (2) and (3),
14
a
=
14
b
=
14
c
or1
c
1
b
1
a
Thus, the required plane isx + y + z = 0. Ans.
Q.81 Let O be the origin, as Q l ies on the given l ine, OQ = )k5ji3(k2ji .
Also OP = k6j2i3 . As PQ is parallel to the plane x 4y + 3z = 1.
PQ )k3j4i( = 0
OPOQ )k3j4i( = 0 (1 + 4 + 6) + ( 3 4 + 15) (3 8 + 18) = 0
11 + 8 13 = 0 =4
1. Ans.
Q.82 Any point on the first l ine is P(3 + 1, + 2 , 2 + 3) and on the second line is
Q( + 3, 2 + 1, 3 + 2) P and Q represent the same point if = = 1 and the point of
intesection of the given lines is P(4, 3, 5) . The planes given is (a), (b), (c) and (d) all pass
through P. The plane at greatest distance is one which is at a distance equal to OP from the
origin. So the distance of the plane from the origin is 222 534 = 50 which is satisfied
by the plane in(b). Ans.
Q.83 Given points are coplanar,
1z222
12y22122x2
1111
= 0
(Volume of the tetrahedron with given vertices is zero)
0z11101y11
011x1
1111
= 0
z111
1y11
11x1
= 0
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XII Part Test-8 Page # 37
z0x
0yx
11x1
= 0
133
122
RRRRRR
x(0 + y) z (y + xy x) = 0
xy + yz + zx = xyz
1z
1
y
1
x
1
Q.84 If the lines have a common point then there existsand such that
6 = 1 + and 1 + 2 = 1 + 3
= 3, = 2
Q.85 )cb(a
=
c)ba(b)ca(
)ac(b
= a)bc(c)ab(
)ba(c
= b)ac(a)bc(
Since the dot product is commutative, we have
0)ba(c)ac(b)cb(a
Q.86
a b c Square
a b a b2 2 2 . =
c 2
cos=
c a b
a b
2 2 2
2
Q.87 Coefficient of x11 in (x + x2 + ... + x6)3
= coefficient of x8 in (1 x6)3 (1 x)3
= coefficient of x8 in (1 3x6) (1 + 3C1
x + 4C2
x2 + ...)
= 10C8 3(4C2) = 27
Q.88 The line can be written as1
3/1x =
2
3/1y =
3
1z which passes through the point whose
position vector is kj3
1i
3
1
and is parallel to the vector k3j2i and hence its
equation is r = kj3
1i
3
1 + k3j2i .
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Q.89 Let
S =
01n2
+
11n2
+ +
n1n2
(i)
Using
rn
=
rnn
, we can write (i) as
S =
1n1n2
n21n2
1n21n2
(ii)
Adding (i) and (ii), we get
2S =
1n21n2
01n2
= 22n+1
S = 22n = 4n
The number of ways of choosing r books out of 2n + 1 is
r1n2
. We are given
255n1n2
21n2
11n2
4n 1 = 255 4n = 256 = 44 n = 4 .
Q.90 If l, m, n denote the direction ratios of L1 then l + m n = 0 and l 3m + 3n = 0l= 0, m = n direction ratios of L
1are 0, 1, 1 similarly for L
2and L
3, we find that the
direction ratios of both are 0, 1, 1 showing that L1, L
2, L
3are parallel, thus statement-1 is
false.
Statement-2 is true, because solving the given equations we get x = 0, y z = 1 and
y z = 2/3 which is not possible.