Class XII Questions Engg

8/13/2019 Class XII Questions Engg

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Sample Paper Class XII[2]

PART-I : PHYSICSSECTION A

(Single Correct Answer Type)

This section contains 12 multiple choice questions. Each question has 4 choices (A), (B), (C) and (D),out of which ONLY ONEis correct.

1. What is the average velocity during time interval t= 2 s to t= 5 s in the following position time curve?

1 2 3 4 5

2

4

6

x(m)

t(s)

P

Q

(A) 2 m/s (B) 2/3 m/s (C) 1.2 m/s (D) 0.4 m/s

2. Two different balls of massesm1and m

2are allowed to slide down from rest and from same height

halong two inclined planes having different inclination and . Then

h

m2m1

(A) The final speed acquired by them will be the same

(B) The final speed acquired by them will be different

(C) The times taken by them to reach the bottom will be the same

(D) None of these

3. A body constrained to move in y-direction is subjected to a force given by N)6152( kjiF

.The work done by this force in moving the body a distance of 10m along the y-axis is

(A) 20 J (B) 150 J (C) 60 J (D) 190 J

4. A block of mass m= 0.1 kg is released from a height of 4 m on a curved smooth surface. On thehorizontal smooth surface it collides with a spring of force constant 800 N/m. The maximumcompression in spring will be (g= 10 m/s2)

4m k=800N/m

(A) 1 cm (B) 5 cm (C) 10 cm (D) 20 cm

5. If a body is to be projected vertically upwards from earths surface to reach a height of 10R fromsurface of earth, (where Ris the radius of earth), the velocity required to do so is

(A)

Rg

11

24(B)

Rg

11

22(C)

Rg

11

20(D)

Rg

11

18


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[3]Sample Paper Class XII


6. A tuning fork of frequency 256 Hz is excited and held at the mouth of resonance column of fundamentalfrequency 254 Hz. Choose the correct statement

(A) 2 beats per second will be heard (B) 4 beats per second will be heard

(C) 1 beat per second will be heard (D) No beat will be heard

7. In a parallel-plate capacitor of capacitance C, a metal sheet is inserted between the plates,symmetrically and parallel to them. The thickness of the sheet is half of the separation between theplate. The capacitance now becomes

(A) 4C (B) 2C (C) C/2 (D) C/4

8. A charged particle moves in a uniform magnetic field of induction B

with a velocity v

. The change

in kinetic energy in the magnetic field is zero when the velocity v

is

(A) parallel to B

(B) perpendicular to B

(C) at any angle to B

(D) none of these

9. Graph of specific heat at constant volume for a monoatomic ideal gas is

(A)CV

T

(B)CV

T

3R

(C)

CV

T

3R/2(D) CV

T

10. The material which shows the effect on magnetic lines of force shown in figure, when placed in auniform magnetic field is called

Magnetic fieldLines

(A) paramagnetic (B) diamagnetic

(C) ferromagnet (D) antiferromagnetic

11. What is the ratio of the circumference of the first Bohr orbit for the electron in the hydrogen atom tothe de-Broglie wavelength of electrons having the same velocity as the electron in the first Bohr orbitof the hydrogen atom?

(A) 1 : 1 (B) 1 : 2 (C) 1 : 4 (D) 2 : 1

12. Which of the following gates will have an output of 1 ?

(A)1

1(B)

1

0

(C)1

0(D)

0

0


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SECTION B

(Comprehension Type)

This section contains 3 paragraphs. Based upon the first and second paragraph 3 multiple choice questionsand based upon the third paragraph 2 multiple choice questions have to be answered. Each of thesequestions has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct.

Paragraph-1

In YDSE, when dichromatic source of light is used we get interference pattern which is obtained bycombination of interference pattern due to each wavelength. A black line is obtained on screen wherea minima due to each wavelength coincides. Similarly, when polychromatic source is taken, saywhite light source, resulting interference pattern is superimposition of interference pattern from eachwavelength as a result at which we get white central bright fringe surrounded by few coloured fringeson both sides of central bright fringe and then uniform illumination of screen. In a typical YDSE setup, distance between slits(d) is 1mm and screen is placed at a distance (D) of 1 m from slits. The

source of light used is dichromatic emitting waves of wavelength 1= 500 nm and

2= 700 nm.

13. Fringe width due to 1is

(A) 5 104m (B) 4 105m (C) 4 106m (D) none

14. The position of first black line from central maxima is

(A) 28 103m (B) 17.5 104m (C) 28 105m (D) none

15. If dichromatic source is replaced by white light source, then fringe nearest to central bright fringe is

(A) violet (B) yellow (C) red (D) none

Paragraph-2

A glass capillary of length 0.11 m is sealed at the upper end and having internal diameter 2 105m.

The capillary is immersed vertically into a liquid of surface tension 5.0 102

N/m very slowly in sucha way that the liquid level inside and outside the capillary becomes same.

Answer the following questions based on the above statement. (atmospheric pressureP0= 1.01 105

N/m, angle of contact zero)

16. What is the pressure of gas inside the tube after immersing into the liquid?

(A) 2.06 105N/m (B) 1.06 105N/m (C) 1.01 105N/m (D) none of these

17. To what length has the capillary to be immersed so that the liquid level inside and outside the capillarybecomes same?

(A) 0.01 m (B) 0.02 m (C) 0.03 m (D) 0.04 m

18. What is the radius of meniscus inside tube?

(A) 1.00 105m (B) 2.03 104m (C) 1.03 104m (D) 1.08 106m


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Paragraph -3

The potentiometer consists of basically a uniform wire of resistance Rsthrough which a steady

current flows as shown. When a source of precisely known emf Es(standard cell) is connected

between pointAand Nand tapping is adjusted till no current passes (null point) in the galvanometerGthen

SSiRE (i)

Now replacing the source ESby unknown potential difference V(to be measured), the balance point

is achieved by shifting the tapping for value RXso that

XiRV

From (i)S

X

S R

R

E

V

BN

G

REs

RhKBattery

i

Rs

A

or SS

X

SS

X

EL

L

ER

R

V

orXKLV

With S

S

L

EK Potential gradient

19. The current in a potentiometer wire is adjusted to give a null point at 56 cm with a standard cell ofemf of 1.02 V. The emf of another cell for which the null point is obtained at 70 cm is :

(A) 0.78 V (B) 1.275 V (C) 1.375 V (D) 1.150 V

20. A potentiometer wire of length 100 cm has a resistance of 10. It is connected in series with aresistance and a cell of emf 2V and negligible internal resistance. A source of emf 10 mV is balancedagainst a length of 40 cm of the potentiometer wire. The value of external resistance is :

(A) 370 (B) 420 (C) 560 (D) 790


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30. The rate law for the following intramolecular Cannizzaro reaction will be

OCCHPhHCCPh OH

O O OOH

(A)2]HO][HCCPh[krate

||||OO

(B)

rate = k[PhCCH]2[OH]

O O

(C) ]HO][HCCPh[krate||||OO

(D) 22 ]HO[]HCCPh[krate||||OO

31. Predict the product in the following reaction

O

O

OH/H)ii(

OH)i(

2

product.

(A)

OH

COOH(B)

OH

(C)

COOH

OH

(D) O

32. The major product of the following reaction is

NH2

CH(OCH3)2

NaNO2

aq. H2SO4, Product

(A)

OH

CH(OCH3)2

(B)

NH2

CH(OH)2

(C)

OH

CHO

(D)

CHO


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SECTION B


This section contains 2 paragraphs. Based upon the first & second paragraph 3 multiple choice questionsand based upon the third paragraph 2multiple choice questions have to be answered. Each of these

questions has four choices (A), (B), (C) and (D) out of which ONLY ONEis correct.

Paragraph-1

Consider the following energy level diagram :

6C(s) + 6H (g) + 9O (g)2 2

C H O + 6O (g)6 12 6 2x

y z

6CO (g) + 6H O ( )l2 2

Energy

Answer the following questions on the basis of the given diagram :

33. The heat of formation of glucose is

(A) x (B) y (C) x y (D) x + z

34. In the given diagram z refers to

(A) 0f 26 H of CO (B) 0f 6 12 6H of C H O

(C) 0c 6 12 6H of C H O (D)0 0c (s) f 2H of C H of H O

35. The quantity y is refers to

(A) 0 0c (s) f 2H of C H of H O (B)0 0c 6 12 6 f 6 12 6H of C H O H of C H O

(C) x z (D) 0 0c 6 12 6 f 2H of C H O H of CO

Paragraph-2

Ortho boric acid is a white crystalline solid. It is soluble in water. It can be prepared by acidifyingaqueous solution of borax on heating. Borax first loses water molecules and swells up. On furthestheating it turns into a transparent liquid, which solidifies into glass like material known as borax bead.

36. Boric acid crystallizes in a layer structure in which H3BO

3are bonded together by

(A) Dative bond (B) Hydrogen bond

(C) Van der waals force (D) Ionic and Dative bonds


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37.375K 375 K Red heat

3 3acid acid

H BO X Y Z

X, Y and Z are

(A) B2O

3, HBO

2and H

2B

2O

4(B) HBO

2, H

2B

2O

7, B

2O

3

(C)HBO2, B

2O

3, H

2B

4O

7(D) B

2O

3, H

2B

4O

7, B(OH)

3

38. From which of the following B2H

6does not liberate H

2?

(A) H2O (B) KOH (C) HCl (D) Cl

2

Paragraph-3

A chemist performs the following reactions:

(i) K2[PtCl

4] + 2NH

3 A + 2KCl

(ii) [Pt(NH3

)4

](NO3

)2

+ 2KCl B + 2NH3

+ 2KNO3

She finds both A and B are white, diamagnetic, crystalline compounds that give elemental analysesfor the formula PtCl

2(NH

3)2. However A is more soluble in polar solvents, such as ethanol, while B is

soluble in petroleum ether and CCl4.

Another chemist who reads a report of this experiment and immediately identifies A and B. Sincenickel is in the same group of the periodic table as platinum, he decides to perform the same experimentwith Ni(II) but is unsuccessful. He obtains some K

2NiCl

4, but when he attempts to run reaction (i), the

only products he is able to isolate are Ni(NH3)6Cl

2and KCl. When tripheyl phosphine, Ph

3P, is used in

place of ammonia as one of the ligands (chloride ion is still the second ligand), compound C is isolated.This compound analyses for the empirical formula NiCl

2(Ph

3P)

2, and is greenish, paramagnetic, and

soluble in organic polar solvents. Regardless of the reaction conditions or concentrations chosen,

only C is found; no other isomers are observed.

39. The structure of A is

(A)

ClNH3

NH3

Cl

Pt(B)

ClCl

NH3

NH3

Pt(C)

ClNH3

NH3

Cl

Pt(D)

NH3NH3

Cl

Cl

Pt

40. Compound C is

(A)

ClPh3P

Ph3P

Cl

Ni(B)

ClCl

Ph3P

PPh3

Ni

(C)

ClPh3P

PPh3

Cl

Ni(D)

Cl

PPh3

Cl

Ni

PPh3

Ni

ClCl


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PART-III : MATHEMATICSSECTION A

(Single Correct Answer Type)

This section contains 12 mult iple choice questions. Each question has 4 choices (A), (B), (C) and (D), out

of which ONLY ONEis correct.

41. L1and L

2are two lines. If the reflection of L

1in L

2and the reflection of L

2in L

1coincide then the angle

between the lines is

(A) 30 (B) 60 (C)45 (D) 90

42. If each critical point of f(x) = 31 2nn n(x ) (x ) (x ) , where 1 2 3n , n , n I

+is either local maximum or

local minimum then

(A) n1, n

2, n

3are even integer (B) n

1is odd , n

2is even , and n

3is even

(C) n1,

n2, n

3prime numbers (D) n

1, n

2, n

3are odd integers

43. The function (x) = x

x x

2e 1+ 1 is

(A) an odd function (B) an even function

(C) neither an odd nor an even function (D) a periodic function

44. If A1, A

2, ..., A

8are independent events such that i

1P A , 1 i 8

i 1

, then the probability that none of

the events occurs is

(A)2

9(B)

1

3(C)

1

2(D)

1

9

45. If a

, b

, c

are unit vectors such that | a

+ b

+ 3 c

| = 4. Angle between a

and b

is 1, between b

and

c

is 2and between a

and c

varies in2

,6 3

, then maximum value of cos1+ 3cos

2is

(A) 3 (B) 4 (C)2 2 (D)6

46. Let f : R R and g : R R be two oneone and onto functions such that they are the mirror imagesof each other about the line y = a. If h : R R such that h(x) = f(x) + g(x), then h(x) is

(A) oneone onto (B) oneone into (C) many-one onto (D) many-one into

47. If 2 4 2 4 6a x b y c , then the maximum value of xy is

(A)2c

ab(B)

3c

ab(C)

3c

2ab(D)

3c

2ab

48. The solution of the equationdy x(2logx 1)

dx siny ycos y

is

(A)2

2 xy sin y x logx c2

(B) 2y cos y x (log x 1) c

(C)2

2 xy cos y x logx c2

(D) 2y sin y x log x c


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49. If the graph of Nbabxaxxxf ,,2)( 23 cuts the xaxis at three distinct points, then the minimum

possible value of ba is

(A) 2 (B) 4 (C)6 (D)8

50. Let P(x) be a polynomial of least degree whose graph has three points of inflexion (1, 1), (1, 1)and a point with abscissa 0 at which the curve is inclined to the axis of abscissas at an angle of 60.

Then 1

0

)( dxxP equal to

(A)7

2

14

33 (B) 12 (C) 122 (D) 7

2

14

33

51 . Let f(x) = ax5+ bx3+ cx 5, where ba, and care constants. If 7)7( f , then )7(f equals

(A) 17 (B) 7 (C)14 (D)21

52. Let1

1

0 1

xeI dx

x

and

1

2

0

3

2

32

x

x dxI

e x. Then

1

2

I

Iis

(A)3

e(B)

3

e(C) 3e (D)

1

3e

SECTION B


This section contains 2 paragraphs. Based upon the first & second paragraph 3 multiple choice questions

and based upon the third paragraph 2multiple choice questions have to be answered. Each of thesequestions has four choices (A), (B), (C) and (D) out of which ONLY ONEis correct.

Paragraph-1

In a tournament, there are sixteen players S1, S

2, , S

16and divided into eight pairs at random. From

each game a winner is decided on the basis of a game played between the two players of the pair.Assuming that all the players are of equal strength

53. The probability that S1is one of the winner

(A)8

15(B)

1

2(C)

1

3(D)

7

30

54. The probability that exactly one of S1or S2is a winner

(A)8

15(B)

1

2(C)

1

3(D)

7

30

55. Both S1and S

2are among eight Winners

(A)8

15(B)

1

2(C)

1

3(D)

7

30


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Paragraph-2

Integration plays a vital role in proving identities involving binomial coefficients whose algebraic methodof proving is, in general, cumbersome and requires the help of Mathematical Induction. If we applyboth integration and induction/recursion techniques, several elegant binomial identities are proved.For instance

n 1n1 2 n

00

C C ( 1) C 1C ... (1 x) dx

2 3 n 1 n 1

where nr rC C ,r 0,1,2,....,n

56. Ifk kn m

n m1 k 2 k

k 0 k 0

( 1) ( 1)S C ,S C ,

k m 1 k n 1

where m > n then,

(A) 12 S

nm

nmS

(B)

12 SS

(C)12 SS (D) 021 SS , for all mand n

57. The value of the binomial seriesn

CCCC n

n 132

1

)1(......

32

must be equal to

(A)n

1.....

3

1

2

11 (B)

n

n 1)1(.....

4

1

3

1

2

11

(C) 2221

.....

3

1

2

11

n

(D) 2

1

222

)1(.....

4

1

3

1

2

11

n

n

58. The compact value of series12

)1(.......

753321

0

n

CCCCC n

n

must be equal to

(A) 2

2

)!(

)!12(2

n

nn

(B))!12(

)!(2 22

nn

n

(C) 22 )!(2 nn (D)12

2

nn

Paragraph-3

A continuous function )(xf satisfying 3224 2)(4 xxxfxx for all ].2,0[x Such that the area

bounded by ,4),( 24 xxyxfy the y-axis and the line tx ( )20 t is ktimes the area bounded

by ,2),( 32 xxyxfy y-axis and the line x= t(0 t 2). Then

59. The function )(xf , is given by :

(A) ])2(2[1

1 234 xkkxxk

(B) ])2(2)2([1

1 234 xkxkxk

(C) ])2(2)2([1

1 34 xkxkxk

(D) ])2(2[1

1 34 xkkxxk

60. If k = 0; then )(xf is symmetric about :

(A) origin (B) y-axis (C)x-axis (D)y = x

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Class XII Questions Engg