Iit Model Paper 7

8/20/2019 Iit Model Paper 7

http://slidepdf.com/reader/full/iit-model-paper-7 1/19

IMPORTANT INSTRUCTIONS:

There are three parts in the question paper A, B, C consisting of Physics

Maths and Chemistry having 30 questions in each part of equal weightage.

Each question is allotted 4 (four) marks for each correct response.

Candidates will be awarded marks as stated above in instruction for correct

response of each question. 1/4 (one fourth) marks will be deducted forindicating incorrect response of each question. No deduction from the total

score will be made if no response is indicated for an item in the answer

sheet.

There is only one correct response for each question. Filling up more than

one response in each question will be treated as wrong response and marks

for wrong response will be deducted accordingly as per instruction

PHYSICS

1. In a cylindrical region of radius R, a time varying magnetic field B kt exists as

shown in the figure 0k . A charged particle having charge q located at a distance d

from centre of cylinder is situated at P. This charged particle is taken slowly form P to

via the path shown in the figure, with the help of an external agent. The work done

by this force (external agent) during the process, is

d

Pq

R

a)2

4

q R k πb)

2

q R d k π c)

3

2

q R k

d

πd) zero

2. For a process on a system (gas enclosed in a vessel), the p V graph is shown in the

figure. For this process three statements are given as:



p

V

pV cons tant

I. During the process, work done by the system is continuously increasing.

II. During the process, work done by the system is zero.

III. During the process, internal energy of the gas is continuously increasing.

IV. During the process, heat supplied to the system is continuously increasing.

a) all the four statements are correct b) only I and IV are correct

c) only II and IV are correct d) no statement is correct

3. The displacement x of a particle as a function of time t is shown in the figure. The

figure indicates:

t

x

a) the particle starts with a certain velocity, but the motion is retarded, and finally the

particle stops

b) the velocity of the particle is constant throughout

c) the acceleration of the particle is constant throughout

d) the particle starts with certain velocity and then its motion is uniformly accelerated

4. From a conducting ring of radius R which carries a charge Q (uniformly distributed)

along it periphery a small length dl is cut-off. The electric field at the centre due to theremaining wire is

a)2 3

08

Q dl

Rπ εb)

2

04

Q

Rπεc) zero d) cannot be determined

5. The charge on two plates of a parallel plate capacitor of capacitance C are 3Q and – Q,

respectively. The potential of the capacitor is [None of the plates of capacitor is

grounded].

a) Q

C b)

3Q

C c)

4Q

C d)

2Q

C



6. In the circuit shown in the figure, the charges on capacitors 1C and 2C are respectively

[In steady state].

1 E 2 E

1C

2C R

a) 1 1C E and 2 1 2C E E b) 1 1C E and 2 2C E

c) 1 1C E and 2 1 2C E E d) 1 1C E and2

2 12 1

2

C E C E

E

7. A battery of emf E and negligible internal resistance is connected to a resistor R.

Taking the heating effect of current and its further effects on circuit into the

considerations, indicate which of the plots shown in figure best represents the rate of

production of thermal energy in the resistor.

t

P

A

B

C

D

a) A b) B c) C d) D

8. A transparent sphere has its right half of the curved surface polished so that it acts as a

mirror. A paraxial light ray is incident from the left and emerges as shown in the

figure. The refractive index µ of the material of cylinder is:

a) 1.5 b) 1.7 c) 2.0 d) 2.3

9. A solid cylinder is performing pure rolling motion on a moving platform as shown.

Which of the relation between, 0 , ,v Rω and v is correct?

R

ω

0v

v



a) 0v Rω b) 0v v Rω c) 0v v Rω d) 0v v

10. In steady state find the current through branch containing inductor and voltage across

capacitor. R

2 RC

L 2 R

R E

a) ,2 2

E E amp volt

Rb) ,

9 2

E E amp volt

Rc) ,

3 4

E E amp volt

Rd) ,

9 4

E E amp volt

R

11. A doubly ionized 2 Li ion in ground state absorbs 91.8 eV of energy. The increase in

angular momentum of electron is 34[ 6.63 10 ]h J s .

a) 342.11 10 J s b) 33

0.53 10 J s

c) 341.05 10 J s d) cannot be computed

12. A sound source of frequency f sends waves of wavelength λ with speed v in some

medium. If the frequency is changed from 2 f to f , then the new wavelength and the

wave speed are respectively,

a) and vλ b) 22

and vλ c)2

and vλ d)4 2

vand λ

13. A stationary source generates 5.0 Hz water waves whose speed is 2 m/s. A boat is

approaching the source at 10 m/s. The frequency of these waves as observed by a

person on the boat, is (assume Doppler Effect is valid)

a) 5 Hz b) 10 Hz c) 20 Hz d) 30 Hz

14. A stationary body of mass m is slowly lowered onto a massive platform of mass

M m moving at a speed 4 m/s as shown in the figure. How far the body slides

along the platform? [Take 20.2 10 / and g m sµ ].

m0.2µ

0 4 / v m sSmooth M

a) 8 m b) 12 m c) 6 m d) 4 m



15. The potential energy of a particle of mass 5 kg moving in the x-y plane is given by

7 24 ;U x y J x and y being measured in metre. If the particle starts from origin

from rest, the magnitude of the conservative force acting on the particle is:

a) 25 units b) 24 units c) 7 units d) 84 units

16. A solid sphere of radius R is resting on a smooth horizontal surface. A constant force

F is applied at a height h from the bottom. Choose the correct alternative.

h

a) sphere will always slide whatever be the value of h.

b) sphere will roll without slipping if 0.4h R .

c) sphere will roll without slipping if 1.4h R .

d) sphere never be set into pure rolling

17. Two particles of masses m and M are initially at rest and infinitely separated from each

other. Due to mutual interaction (gravitational) they approach each other. Their

relative velocity of approach when they are at a distance d , is:

a)2Gd

M mb)

2G M m

d

c)

2GMm

M m d d)

2Gm

d

18. A point of mass 20m kg is suspended by a massless spring of spring constant

2000 / k N m . The point mass is released from rest at 0t when elongation in the

spring is 15 cm. The equation of displacement of particle from its mean position as a

function of time is given by: [Take 210 / g m s and downward direction as + ve].

(Assume Hooke’s law to be valid).

m

k



a) 10 sin 106

y cm t π

b) 5 sin 10 y cm t

c) 5 sin 102

y cm t π

d) 5 sin 102

y cm t π

19. The length of an elastic string is a metre when the tension in it is 4 N and b metres

when the tension in it is 5 N. The length of string in metres when the tension in the

string is 9 N, is

a) a b b) 5 4b a c) 4 5a b d) 9 5b a

20. Two particles A and B are moving uniformly around concentric circular paths of radii

Ar and Br . If both the particles complete one rotation in the same time, then:

a) the ratio of their angular velocity is 1

b) the ratio of linear velocity is A

B

r

r

c) the ratio of the force required for their motion may not be A

B

r

r

d) all of the above

21. For CE configuration of a transistor,

a) input resistance is very small while output resistance is very high

b) input resistance is very large while output resistance is very small

c) both input and output resistances are very small

d) both input and output resistances are very large

22. A small mirror of area A and mass m is suspended by means of light thread, in vertical

plane. On the mirror, a beam of light of intensity I , is made to be incident

perpendicular to mirror, due to which mirror is displaced and thread makes a small

angle α with the vertical. Assuming mirror to be totally reflecting, the value of α is

[ c speed of light, a is in radians].

a)2 IA

cmgb)

IA

cmgc)

3 IA

cmgd)

2

IA

cmg

23. A piece of ice is floating in water. The fraction of volume of the piece of ice outside

the water is 3[ 900 / ice kg mρ and 31000 / water kg mρ ].

a) 0.21 b) 0.01 c) 0.1 d) 0.9

24. Some physical quantities, a, b, c, x are related as3 2

a b xc

¸if the % error in , ,a b c are

2% , 1% and 4% respectively, then % age error in x is



a) 8% b) 12% c) 4% d) 10%

25. Density of a liquid varies with depth as hρ α . A small ball of density 0ρ is released

from the surface of the liquid. Then(a is A positive constant)

a) the ball will execute simple harmonic motion of amplitude 0ρ

α

b) the mean position of the ball will be at a depth 0

2

ρ

αfrom the free surface

c) the ball will sink to a maximum depth of 0ρ

α

d) all of the above

26. The time taken by a transverse pulse to travel full length of a uniform rope of mass 0.1

kg and length 2.45 m hanging from the ceiling, isa) 1 s b) 0.5 s c) 2 s d) 1.5 s

27. Two point white dots are 1 mm apart on a black paper. They are viewed by eye of

pupil diameter 3mm. Approximately, what is the maximum distance at which these

dots can be resolved by the eye? [Wavelength of light = 500 nm].

a) 5 m b) 1 m c) 7 m d) 3 m

28. Which of the following statement leads us to identify the p-side of p-n junction

diode?(Beep is indication of flow of current)

a) when positive lead of multimeter is connected to one leg of diode and negative lead

of multimeter to other leg, then a beep is obtained

b) when p-side of diode is connected to negative lead of multimeter and n-side to

positive lead, then a beep is obtained

c) when one leg of diode is connected to – ve lead of multimeter and other leg to +ve

lead, then no beep is obtained

d) both (a) and (c)

29. To identify whether a p-n-p transistor is working or not, using multimeter, which

statement serves the purpose?

a) the common lead of multimeter is connected to base and other lead to first emitter

and then to collector, only 1st

connection shows the continuity

b) the common lead of multimeter is connected to base and other lead to first emitter

and then to collector, both the connections shows the continuity



c) the common lead of multimeter is connected to base and other lead to first emitter

and then to collector, none of the connection shows the continuity

d) all of the above

30. In measurement of mass of a given object by the principle of moments, the meter scale

is hung from its mid-point. A known weight of mass 2 kg is hung at one end of metre

scale and unknown weight of mass m kg is hung and 20 cm from the centre on otherside. The value of m is

a) 2 kg b) 5 kg c) 2.5 kg d) 0.8 kg

MATHEMATICS

31. If 1 2 3, , p p p denote the distance of the plane 2 3 4 2 0 x y z from the planes

2 3 4 6 0 x y z , 4 6 8 3 0 x y z and 2 3 4 6 0 x y z respectively, then

a)1 2 3

8 0 p p p b) 2 2

3 2

16 p p c) 2 2

2 1

8 p p d)1 2 3

2 3 29 p p p

32. A ray of light incident at the point 2, 1 gets reflected from the tangent at 0, 1 to

the circle 2 2 1 x y . The reflected ray touches the circle. The equation of the line

along which the incident ray moved is

a) 4 3 11 0 x y b) 4 3 11 0 x y c) 3 4 11 0 x y d) 3 4 11 0 x y

33. In a shop there are five types of ice-creams (each type is available unlimited).A child

buys six ice-creams.

Statement-1: The number of different ways the child can buy the six ice-creams is10

5C .

Statement-2: The number of different ways the child can buy the six ice-creams is

equal to the number of different ways of arranging 6 A’s and 4 B’s in a row.

a) Statement 1 is true, Statement 2 is true; Statement 2 is not a correct explanation for

Statement1.

b) Statement 1 is true, Staement2 is false.

c) Statement 1 is false, Statement 2 is true.

d) Statement 1 is true, Statement 2 is true, Statement 2 is a correct explanation for

Statement 1.

34. The mean deviation of items , , 2 .................., 2 x x y x y x ny from mean (y > 0) is

a) 1

2 1

n n y

n

b)

1

2 1

n y

n

c)

2 1

ny

n d)

2 1

1

n y

n n



35. If PQ is a double ordinate of the hyperbola2 2

2 21

x y

a b such that OPQ is an equilateral

triangle, O being the center of hyperbola. Then the eccentricity e of the hyperbola

satisfies.

a) 1 2 3e b)3

3e c)

3

2e d)

2

3e

36. Let ;a i j k b i j k

and c

be a unit vector perpendicular to a

and coplanar with

a

and b

, then c

is

a)1

2 j k

b)

1

2 j k

c)

12

6i j k

d)

12

6i j k

37. Out of 3n consecutive natural numbers, 3 natural numbers are chosen at random with

replacement. The probability that the sum of the chosen numbers is divisible by 3 is

a) 2

3 3 2

2

n n n b)

23 3 2

2 3 1 3 2

n n

n n

c)

23 3 2

3 1 3 2

n n

n n

d)

3 1 3 2

3 1

n n n

n

38. If 3 4

23 4

x f x

x

, then f x dx is

a) 2 3 4log

3 4

x xe c

x

b)8 4

log 1

3 3

x x c

c)8 2

log 13 3

x x c d)8 2

log 13 3

x x c

39. Let A be a 2 2 matrix with real entries. Let I be the 2 2 identity matrix. Denote by

tr A , the sum of principal diagonal entries of A . Assume that 2 A I .

Statement-1: If A I and A I , then det 1 A .

Statement-2: If A I and A I , then 0tr A .


Statement1.




Statement 1.

40. Statement -1: If

2 0 1

5 1 0

0 1 3

A

then adj adjA A



Statement-2: If A is a non-singular matrix of order ‘n’ then

21n

adj adjA A


Statement1.




Statement 1.

41. Statement-1: An equation of a common tangent to the parabola 2 16 3 y x and the ellipse

2 22 4 x y is 2 2 3 y x

Statement-2: If the line

4 3

, 0 y mx m

m

is a common tangent to the parabola

2 16 3 y x and the ellipse 2 22 4 x y , then m satisfies 4 2

2 24m m .


Statement1.



d) Statement 1 is true, Statement 2 is true, Statement 2 is a correct explanation for Statement 1.

42. Statement-1: 1

0

1 2 2n

n n

r

r

r C n

.

Statement-2: 1

0

1 1 1n

n nn r

r

r

r C x x nx x


Statement1.




Statement 1

43. The equation sin 1 02

x π has one root in interval

a) 0, 2

π

b) ,02

π

c)

3

, 2

π

π

d) , 2

π

π

44. One of the solution of differential equationsin

dy y

dx y y x

is



a) cos 2008 sin y x y y b) cos 2008 sin y x y y

c) 2 2sin 420 x y d) 2( cos ) 20 sin y x y y

45. The sums of first n terms of two A.P.’s are in the ratio 3 8 : 7 15n n .The ratio of

their 12th

terms is

a)4

9b)

7

16c)

3

7d)

16

7

46. A person is permitted to select at least one and at most n coins from a collection of

2 1n (distinct) coins. If the total number of ways in which he can select coins is 255,

then n equals

a) 4 b) 8 c) 16 d) 32

47. The statement p q q

is

a) p q b) p q c) p q d) p q

48. In a ABC , if

1

1 0

1

a b

c a

b c

, then 2 2 2sin sin A Sin B C is equal to

a)9

4b)

4

9c) 1 d) 3 3

49. Let 1 2 3 .... 100 f x x x x x and g x f x . 2

f x f x , then 0g x ,

has

a) no solution b) exactly one solution

c) exactly two solutions d) minimum three solutions

50. If f x be a continuous function for all real values of x and satisfies

822

3 2

x

x

x

f t dt t f t dt

, then

1

1/ 2 f x dx is equal to

a)5

ln8

b)1 8

ln2 5

c)8

2ln5

d)1 5

ln2 8

51. The number of distinct real values of λ for which the vectors 3 3,i k i jλ λ

and

2 sini j k λ λ λ

are coplanar is

a) 0 b) 1 c) 2 d) 3

52. The maximum value of z satisfying the equation 221 1112 3

z z z is:

a) 2 b) 3 c) 4 d) 6



53 The shortest distance between the lines1 2 3

2 3 4

x y z and

2 4 5

3 4 5

x y z is:

a) 1/ 6 b) 1/ 6 c) 1/ 3 d) 1/ 3

54. If 24

sin log

1

e

x f x

x

, then domain and range of f x are respectively given by:

a) 2,1 , 1,1 b) , 2 1, , 0,1

c) 0,1 , 1,1 d) , 2 1, , 0,1

55.

30

1 sin cos log 1lim x

x x x

x

equals:

a) 1/2 b) -1/2 c) 0 d) 1

56. All the points on the curve sin y x x at which the tangent is parallel to x-axis lie on a /an:

a) straight line b) circle c) parabola d) ellipse

57. Two fair dice are rolled simultaneously. It is found that one of them shows odd prime

number. The probability that remaining die also shows an odd prime number, is equal to:

a) 1/5 b) 2/5 c) 3/5 d) 4/5

58. An investigator interviewed 100 students to determine their preferences for the three drinks,

Milk (M), Coffee (C) and Tea (T). He reported the following:

10n M C T , 20n M C , 30,n C T 25,n M T n (only C) = 5,

n (only T ) = 8.Assuming that every student consumes atleast one of the above mentioned

drinks the number of correct statements from the following is:

1) 47n M 2) 45n C 3) 53n T 4) 20n M C T

a) 1 b) 2 c) 3 d) 4

59. Area of the region bounded by the curves log y x x and 2

2 y x x is:

a) 1/2 b) 7/12 c) 5/12 d) 13/12

60. If 1 22 tan log 1 y x x x x ,then:

a) y increases in[0, ) b) y decreases in [0, )

c) y increases in ,0 d) y increases in ,

CHEMISTRY



61. Lemon juice normally has a pH of 2. If all the acid in the lemon juice is citric acid and

there are no citrate salts present, then what will be the citric acid(H.cit) concentration

in the lemon juice? (Assume that only the first hydrogen of citric acid is important).

1

4 1. . 8.4 10a H Cit H Cit K mol lit

a) 48.4 10 M b) 44.2 10 M c) 416.8 10 M d) 212.0 10 M

62. One mole of an anhydrous salt AB dissolves in excess of water with the evolution of

21.0 J mol-1

of heat. If the heat of hydration of AB is -29.4 J mol-1

, then the heat of

dissolution of the hydrated salt AB is

a) 50.4 J mol-1

b) 8.4 J mol-1

c) -50.4 J mol-1

d) -8.4 J mol-1

63. The number of isomers of [Co (NH3)3 Cl3] complex and secondary valency of the

metal ion in the complex respectively are.

a) 3 & 3 b) 2 & 3 c) 2 & 6 d) 3 & 6

64. The order of acidity of compounds I-IV, is-

2CH OH 2CO H OH 3SO H

I II III IV

a) I < III < II < IV b) IV < I < II < IIIc) III < I < II < IV d) II < IV < III < I

65. A concentrated solution of copper sulphate, which is dark blue in colour, is mixed at

room temperature with a dilute solution of copper sulphate, which is light blue. For

this process-

a) Entropy change is positive, but enthalpy change is negative

b) Entropy and enthalpy changes are both positive

c) Entropy change is positive and enthalpy does not change

d) Entropy change is negative and enthalpy change is positive

66. Increasing the temperature increases the rate of reaction but does not increase the-

a) number of collisions b) activation energy

c) number of fruitful collisions d) average velocity of the reactant molecules

67. From equations 1 and 2,



1). 12 0

2( ) ( ) 2( ) 1

19.1 10 1000

2g g g

CO CO O K at C ;

2). 12 0

2 ( ) 2( ) 2( ) 2

17.1 10 1000

2l g g H O H O K at C

The equilibrium constant for the reaction 2( ) 2( ) ( ) 2 ( )g g g lCO H CO H O at the same

temperature, is

a) 0.78 b) 2.0 c) 16.2 d) 1.28

68. Consider the reaction: 2 22 2 NO g NO g O g , In the figure below, identify the

curves X, Y and Z associated with the three species in the reaction

X

Y

Z C

o n c e n t r a t i o n

Time

a) X = NO, Y = O2, Z = NO2 b) X = O2, Y = NO, Z = NO2

c) X = NO2, Y = NO, Z = O2 d) X = O2, Y = NO2, Z = NO

69. Two isomeric compounds I and II are heated with HBr –

OH OH

2CH OH 3OCH

I II

The products obtained are

a)

OH OH

2CH Br OH

b)

Br Br

2CH OH 3OCH

c)

Br Br

2CH Br Br

d)

OH OH

2CH OH 3OCH

Br

Br

70. The number of possible enantiomeric pair(s) produced from the bromination

(Br2 /CCl4) of I and II, respectively, are



3 H C 3CH

3 H C 3CH

3 H C

3 H C 2CH

I II

a) 0,1 b) 1, 0 c) 0, 2 d) 1, 1

71. For the reaction 0 1, 7.5 A B H KJ mol

and 0 1 125S JK mol

. The value of 0G and

the temperature at which the reaction reaches equilibrium are, respectively,

a) 0 1KJ mol

and 400 K b) – 2.5 1KJ mol

and 400 K

c) 2.5KJ mol and 200 K d) 0 1

300KJ mol and K

72. The solubility product of 2

Mg OH is 121.0 10 at 25

0C. Aqueous NaOH solution is

added to a 0.01 M aqueous solution of 2 MgCl . The minimum pH at which precipitation

occurs at 250C is

a) 7.2 b) 7.8 c) 8.0 d) 9.0

73. Diborane is formed from the elements as shown in equation (1)

2 2 62 3 ............ 1 B s H g B H g

Given that

2 2 H O l H O g 0

1 44 H kJ

2 2 32 3/ 2 B s O g B O s 0

2 1273 H kJ

2 6 2 2 3 23 3 B H g O g B O s H O g 0

3 2035 H kJ

2 2 21/ 2 H g O g H O l 0

4 286 H kJ

the 0 H for the reaction (1) is-

a) 36 kJ b) 509 kJ c) 520 kJ d) – 3550 kJ

74. The Crystal Field Stabilization Energy CFSE and the spin-only magnetic moment in

Bohr Magneton (BM) for the complex 3 6K Fe CN are, respectively-

a) 00.0 and 35 BM b) 02.0 3 BM

c) 00.4 and 24 BM d) 02.4 and 0 BM





82. What is the major product of the following reaction sequence?

C 2 HO CH OH

O

2

3

1

2 1

SOCl

CH ONa eq

( )excess

a)

C 2Cl CH Cl

Ob)

C 2ClCH 3O CH

O

c)C 3 2CH O CH

3CH

O

d)

C 3 2CH O CH Cl

O

83. 29.5 mg. of an organic compound containing nitrogen was digested according to

Kjeldahl’s method and the evolved 3 NH gas was absorbed in 20 mL of 0.1 M HCl

solution. The excess of acid required 15 mL of 0.1 M NaOH solution for complete

neutralization. The percentage of nitrogen in the compound is:

a) 29.5 b) 59.0 c) 47.4 d) 23.7

84. Which of the following statement(s) are correct.

(i) More number of oxidation states are exhibited by the actinoids than those by the

lanthanoids due to lesser energy difference between 5 f – and 6d – in actinoids than 4 f

– and 5d – orbitals in lanthanoids.

(ii) There is a gradual decrease in the radii of the trivalent ions with the increasing

atomic number in the lanthanoids series.

(iii) The 5 f -orbitals are deeply seated than the 4 f -orbitals in the atom.

(iv) Zr and Hf have about the same raidus due to lanthanoid contraction

a) (i), (ii), (iv) b) (i), (ii), (iii)

c) (i), (ii) d) (i), (ii), (iii), (iv)

85. With reference the scheme given, which of the given statement(s) about , ,T U V and

W is (are) correct?



3 H C

4 L iA lH

T

E x c e s s o f

3 2C H C O O

U W

3 / C rO H

V

O

O

(i) T is soluble in hot aqueous NaOH

(ii) U is optically active

(iii) Molecular formula of W is 10 18 4C H O

(iv) V gives effervescence with aqueous 3 NaHCO

a) (i), (ii), (iii) b) (i), (iii), (iv) c) (i), (ii), (iv) d) (i), (iii)

86. Choose the correct reason(s) for the stability of the lyophobic colloids.

i) Preferential adsorption of ions on their surface from the solution

ii) Perferential adsorption of solvent on their surface from the solution

iii) Attraction between different particles having opposite charges on their surface

iv) Potential difference between the fixed layer and the diffused layer of opposite

charges around the colloidal particles.

a) (i), (ii), (iii) b) (i), (iii), (iv) c) (i), (ii), (iv) d) (i), (iv)

87. Which of the following statement(s) are correct.

(i) Dα glucopyranose and Dβ glucopyranose are anomers.

(ii) The change in optical rotaion of freshly prepared solution of fructose with time is

known as mutaroation

(iii) Sugars can be detected by Molish’s test.

(iv)Synthesis of each molecule of glucose in photosynthesis involves 10 molecules of ATP.

(v) Biuret test is given by proteins.

a) (i), (ii), (iv), (v) b) (ii), (iii), (v)

c) (i), (ii), (iii), (v) d) (i), (ii), (iii), (iv), (v)

88. In which of the following arrangements, the sequence is not strictly according to the

property written against it?

a) HF HCl HBr HI : increasing acid strength

b) 3 3 3 3 : NH PH AsH SbH increasing basic strength



c) : B C O N increasing 1st

ionization enthalpy

d) 2 2 2 :GeO SnO PbO increasing oxidizing power

89. Four coins of the same size are placed on the corners of a square in such a way that

their centre’s coincide with the corners of the square. Radius of coins is R and edge of

square is 2R . What is maximum radius of a coin that can be placed in the gap of the

above square?

a) 0.155 R b) 0.225 R c) 0.414 R d) 0.732 R

90. During the extraction of iron in the blast furnace,

a) Coke acts as reducing agent in the lower zone and CO acts as reducing agent in the upper

zone

b) CO acts as reducing agent in the lower zone and Coke acts as reducing agent in the upper

zone

c) Coke acts as reducing agent in the lower zone and CO acts as reducing agent in the lower

zone

d) CO acts as reducing agent in the upper zone and Coke acts as reducing agent in the

upper zone

Documents

Iit Model Paper 7