Cycle 2 Quize 3

7/27/2019 Cycle 2 Quize 3

1/18

LOCUS 1

LOCUS:65-A, Ompro Tower, Kalu Sarai, New Delhi-110016, Ph.: 011-46080145-6, Websit:www.locuseducation.org

CYCLE-2, QUIZ-3, CHEMISTRY

1. Which of the following molecules has a Trigonal-Pyramidal shape:

(a) 3PCl (b) 3SO

(c) 23CO (d) 4XeF

2. Which of the following is paramagnetic

(a) CN (b) 2O

(c) CO (d)2NO+

3. The electronic configuration of and element is 2 2 6 2 6 5 11 2 2 3 3 3 4 .s s p s p d s This represents its

(a) Excited State (b) Cationic Form

(c) Anionic Form (d) Ground State.

4. The net Enthalpy change of a reaction is defined as the amount of energy required to break all the

bonds on the reactant molecules minus the amount of energy required to break all the bonds in the

product molecules

ASSERTION (A): For the reaction3 2( ) ( ) ( )CaCO s CaO s CO g

+ the enthalpy change for thereaction cant be ascertained using this definition.

REASON (R) : The definition of Enthalpy given above is only an approximate relationship and

is valid when all substances (REACTANTSAND PRODUCTS) in the reaction are in

gaseous state.

(a) Both A & R are true & R is the correct explanation of A

(b) Both A & R are true but R is not the correct explanation of A

(c) A is true but R is false

(d) R is true but A is false5. The general expression for the half life, 1 2 ,t for an n

th order reaction is:

(a)

1

( 1)

( 1)(2 1)n

nin

n

C

(b)

1( 1)(2 1)n

nin

n

C

(c)1( 1)(2 1)n

nin

n

KC

(d)1

( 1)

( 1)(2 1)n

nin

n

KC

.

6. At constant volume for a fixed number of moles of a gas, the pressure of the gas increases with rise of the

temperature due to:

(a) Increase in molecular attraction

(b) Increase in rate of collisions amongst molecules(c) Increase in average molecular speed

(d) Decrease in mean free path.

7. The state of hybridisation, number of bond-pairs and number of lone pairs for a Xenon Fluoride

compound having square planar structure are:

(a) 2 2 ,5,1sp d (b) 3 2 ,4,2sp d

(c) 2 3,4,2sp d (d) 3 2 ,5,1sp d .

8. The average bond enthalpy of methane is 416 kJ/mol, what does this signify with respect to the

CHbonds in methane

(a) All the CHbonds in methane have a bond enthalpy of 416 kJ/mol(b) Majority ofCHbonds in methane have a bond enthalpy of 416 kJ/mol

(c) The bond enthalpies ofCH bonds in methane lie in the neighbourhood of 416 kJ/mol

(400-430) kJ/mol.

(d) The bond enthalpies ofCHbonds in methane vary significantly from each other but their

average is 416 kJ/mol.


2/18

LOCUS 2


9. What is the standard enthalpy of formation of 2 ( )H O l given

2 2 22 ( ) ( ) 2 ( )H g O g H O l+ ;0 1571 6 kJmolfH

=

(a) 1571 6 kJ mol (b) 1571 6 kJ mol

(c)1

285 8 kJ mol

(d) cant be assertained from the given data.10. Which of these correctly represents the reaction: 1 2k kA B C

(a)

Tmax

Bmax

conc.

Time

(b)

Tmax

Bmax

conc.

Time

C

B

(c)

Tmax

Bmax

conc.

Time

(d)

Tmax

Bmax

conc.

Time

B

C

.

11. Statement A : For a process to be elementary, order must be equal to molecularity.

Statement B: Molecularity is always an integer greater than zero.

Choose the correct option:

(a) both A & B are correct (b) only A is correct

(c) only B is correct (d) both are false.

12. The correct order of increasing CO bond length in CO, 23CO

& 2CO is

(a) 23 2CO CO CO< < (b) 22 3CO CO CO

< > > > (b) 1 4 5 3 2> > > >

(c) 1 5 4 3 2> > > > (d) 4 5 3 1 2> > > > .16. In Thermodynamics, a process is called reversible when:

(a) Surroundings & system change into each other

(b) There is no boundary between system & surroundings

(c) The surroundings are always in equilibrium with the system

(d) The system changes into the surroundings spontaneously

17. For first order reaction:

(a) The degree of dissociation is equal to (1 )Kte(b) A plot of reciprocal concentration of the reactant vs time gives a straight line

(c) The time taken for the completion of 75% reaction is thrice the 1 2t of the reaction(d) The pre-exponential factor in the Arrhenius equation has the dimension of time 1.T

18. The correct hybridisation states of nitrogen in 2 3,NO NO+ &

4NH+ is

(a) 3 2 3, ,sp sp sp (b) 2 3, ,sp sp sp

(c) 3 3, ,sp sp sp (d) 3 2, ,sp sp sp .

19. The correct arrangement of these compounds in increasing order of ionic character is

2 3 2, , ,NaCl CaCl AlCl SnCl

(a) 3 2 2AlCl SnCl CaCl NaCl< < < (b) 2 2 3NaCl CaCl SnCl AlCl< < is

(a) 1

1 1

15 6r

(b) 6 11 1 1

5 6 6r r

(c) 11 1 1

5 6 6r r

(d) None of these.

18. If the system of equations

5 ( )

2 3 9 ( )

3 ( )

x y z i

x y z ii

x y z iii

+ + = + + = + + =

has infinite solutions then

(a) 13, 5 (b) 5, 13 = =(c) 13, 5 = = (d) 5, 13 = .


9/18

LOCUS 9


19. Two of the lines given by the equation 4 3 2 2 3 4 0ay by x cy x dyx ax+ + + + = bisect the angle betweenother two then the necessary and sufficient condition is

(a) 0a b c d + + + = (b) 2 2( ) ( 6 ) 0b d c a+ + =

(c)

2 2

( ) ( 6 ) 0b d c a+ + + = (d) ( )( 6 ) 0b d c a+ + = .20. ABCis an equelateral triangleL,MandNare foot of perpendiculars from a pointPto the sidesAB,

BC, CA respectively.Plies within the triangle and satisfies the conditionPL PN

PM PL= . Then the locus

ofPis

(a) a straight line not passing through origin

(b) a straight line passing through origin

(c) a circle with centre at origin

(d) a circle passing through origin.

21. The decimal parts of two numbers taken at random are found to be upto six places of decimal. Theprobability that the second number can be subtracted from first only when borrowing has to be done

at some place is

(a)

611

20

(b)

611

25

(c)

611

125

(d)

611

120

.

22. p is chosen at random from the closed interval [0, 5]. The probability of existence of three positive

numbers a, b and c in G.P. such that if the sum of their squares 2 2 2( )a b c+ + is 2S , then their sum(a + b + c) ispSis

(a)1

5(b)

2

5

(c)3

5(d)

4

5.

23. Two numbers are selected randomly from the interval [0, 4]. The probability that the square of

exactly any one of the two numbers is greater than the other number is

(a) 13

(b) 58

(c)9

13(d)

4

13.

24.11 5 3 63

( )11 5 3 165

n n n nn N+ + + is

(a) always a positive integerV n N (b) can be a fraction for some n N(c) always an odd numberV n N (d) none of these.


10/18

LOCUS 10


25. ( )

2

222

2 12 2

0

1( 1)

! (1 )

xn

xn

n

xn n x e

n x

+ +=

+ +

is

(a) 21

1 x+

(b) 22

1

x

x+

(c)

2

21

x

x+(d)

2xe .

26. If x andy are positive rational numbers such that1 1

1,x y

+ = then minimum value of3 5x y

x y+ is

(a) 15 (b) 15

(c) 75 (d) 225.

27. If 2 3 1( ) 2 3 ..... ( 1)n nf x x x x nx= + + + Then the value of (1 2)f is

(a)

22 21

3 1

2 1 4 2( 1)

23 9 2

nn

n

n n

+ +

(b)

2 2

3 1

2 1 3 4 21 ( 1)

23 9 2

nn

n

n n

+ +

(c)

21

1

2 1 4 21 ( 1)

3 2 9 2

nn

n

n n

+ +

(d)

2 21

1

4 1 3 4 21 ( 1)

27 2 9 2

nn

n

n n

+ +

.

28. If 1 0i i iL a x b y + = represent three sides of a triangle fori =1,2,3 whose orthocentre is at originthen which of the following is true.

(a) 1 2 1 2 1a a b b= = (b)1 2 1 2

2 3 2 3

1a a b b

a a b b

+ =+

(c)1 2 2 1

2 3 3 2

1a b b a

a b b a

+=

+ (d) None of these.

29. A circle 2 2 4 4 4 0x y x y+ + = is inscribed in a triangle whose two sides are 0x = and 0y = .

The locus of circumcentre of the triangle is 2 2 0.x y xy x y+ + + = Then value ofis(a) 1 (b) 1

(c) 4 (d) 4.

30. 2 21 2

61 4

AX I

=

. Then matrixA is

(a)2 4

1 1

(b)1 1

4 2

(c)4 2

1 1

(d) None of these.


11/18

LOCUS 11


CYCLE-2, QUIZ-3, PHYSICS

1. A ray of light travels from a medium of refractive index to air. Its angle of incidence in the

medium , measured from the normal to the boundary and its angle of deviation is . Which of thefollowing best represent the plot of.

(a)

2

1

O /2

(b)

2

1

O /2

(c)

2

1

/2

(d)

2

1

/2

2. Two moles of an ideal monatomic gas, initially at pressurep1

and volume v1, undergo an adiabatic

compression until its volume becomes v2. Then the gas is given heat Q at constant volume v

2. What

will be the final temperature of the gas?

(a)1 1 2

2 3

P v v Q

R R

+

(b)

5/ 3 2 /3

1 1 2

3

P v v Q

R

+

(c)1 1

2 3

P v Q

R R

+ (d)

7 / 2 5/3

1 1 2 2

2 3

P v v Q

R R

+

3. A wave pulse starts propagating in +x-direction along a non-uniform wire of length 10m with mass

per unit length given by 0m m x= + and under a tession of 100N. Find the time taken by the pulseto travel from lighter end to heavier end. 2 3 3

0( 10 / , 10 / )m kg m kg m = = 9

(a) 3.52sec (b) 2.33sec

(c) 5.91sec (d) 1.5sec

4. Two parallel beams of lightPand Q are incident normally ona prism and the transmitted rays are brought to focus with the

help of a convergent lens as shown in fig. If the intensities of

the upper and lower beams immediately after transmission from

faceACare 4I and I respectively. Find the resultant intensity

at the focus:

(a) 5 I (b) 3 I

L

A

B C

P

Q

(c) 10 I (d) 9 I

5. A convex lens of focal lengthfis placed somewhere between an object and a screen. The distance between

the object and the screen isx. If the magnification is m, the focal length of the lens is given by

(a) 2( 1)

mx

m + (b)2( 1)m x

m

(c) 2( 1)

mx

m (d)2( 1)m x

m

+


12/18

LOCUS 12


6. A point source of lightB, placed at a distanceL in front of the

centre of a plane mirror of weidth d, hangs vertically on a

wall. A man walks in front of the mirror along a line parallel to

the mirror at a distance 2L from it as shown. The greatest

distance over which he can see the image of the light source in

the mirror is:(a) / 2d (b) d 2L

L

dB

(c) 2d (d) 3 d

7. Two coherent point sources S1

and S2

vibrating in phase emit light of wavelength . The Separationbetween the sources is 2. The smallest distance from S

2on a line passing through S

2and

perpendicular to S1S

2, where a minimum of intensity occurs is:

(a)7

12

(b)

15

4

(c)2 (d) 34

8. What should be the minimum value of i1

so that finally ray comes out along AC. is refractive

index of material of prism. Angle of prism is

(a)1sin 1 2

(b) [ ]1sin sin cosA A

A

B C

i1

(c)1 2sin 1sin cosA A

(d) 45

9. Three moles of an ideal gas at 300K are isothermally expanded to five times its volume and heated

at this constant volume so that the pressure is raised to its initial value before expansion. In the

whole process 83.14 kJheat is required.

The value of ( )/P VC C will be:8.31 / molR J=

log 5 1.61e =

(a) 1.42 (b) 1.33

(c) 1.0 (d) 1.75

10. A body cools in 7 minutes from 60C to 40C. What will be its temperature after next 7 minutes?

The temperature. of surrocuding is 10C

(a) 20 C (b) 25 C

(c) 28 C (d) 10 C

11. A sphere of diameter 7 cm and mass 266.5 g floats in a bath of liquid. As the temperature is raised, the

sphere begins to sink at a temperature of 35 C. If the density of the liquid is 1.527 g/cc at 0 C. Find the

Coefficient of cubical expression of liquid. Neglect the expression of sphere.

(a) 28.5 10 (b) 37.5 10(c) 4

7.5 10

(d) 4

8.5 10


13/18

LOCUS 13


12. Suppose we create an artificial atmosphere of gas for the verification of second law of thermodynamics

suppose the mass of gas taken is m. It is slowly heated from T1

to T2. What will be the change in

entropy of the atmosphere, if its heat capacity is C?

(a)1 2

2 2

1 2

T Tmc

T T

+ (b)

2

1

lnT

mc

T

(c)2 1

1

T Tmc

T

(d) zero as the process is reversible

13. Two bodies ofA andB have thermal emissivities of 0.01 and 0.81 respectively. The outer surface

areas of the two bodies are same. They emit total rodiant power at the same rate. The wavelengthB

corresponding to maximum spectral radiancy in the radiation fromB is shifted from the wavelength

corresponding to maximum spectral radiancy in the radiation -fromA by 1.00pm. If the temperature

ofA is 5202 K, wavelengthB will be

(a) 2 m (b) 1.5 m(c) 7400 A (d) 2000 A

14. Suppose we have two covalent molecules, which individually can be

treated as dipole. The molecules are oriented perpendicular to each

other.

The force on 2 due to 1 will be

(a)1 2

4

0

1

4

P P

r (b)1 2

4

0

1 3

4

P P

r

P2

2

1

P1

r

(c) 1 240

14 4

P Pr (d)

1 24

0

1 24

P Pr

15. A 10 F capacitor is charged through a resistance of 0.1 M from a battery of 1.5V. The timerequired for the capacitor to get char.ged upto 0.75V for the situations shown will be respectively

(a) 0.693 & 0.693

(b) 0 & 0

(c) 0 & 0.693RE CEC

( )a ( )b

R

(d) 2 Cu 2 & Cu 2

16. The first overtone of an open organ pipe beats with the first overtone of a closed organ pipe with abeat frequency of 2.2 Hz. The fundamental frequency of the closed organ pipe is 110 Hz. The lengths

of pipe will be 1 0( closed; open)L L= =(a) 1 00.75 & 0.75L m L m= = (b) 1 01 & 2.13L m L m= =(c) 00.75 & 0.99CL m L m= = (d) 01 & 1.5CL m L m= =

17. The specific heat of many solids at low temperatures varies with absolute temperature Taccording to the

relation 3 ,s aT= where a is a constant. Find the heat energy required to raise the temperature of a mass mof such a solid from 0 to 20K.

(a) 44 10 ma (b) 43 10 ma(c) 42 10 ma (d) 41 10 ma .


14/18

LOCUS 14


18. The first allowed excited state of hydrogen atom is 10.2 eV above its lowest energy (ground) state. To what

temperature should hydrogen gas be raised so that inelastic collisions may excite an appreciable number of

atoms to their first excited state?

(a) 68.0 10 K (b) 47.88 10 K(c) 46.44 10 K (d) 58.80 10 K .

19. ThePVdiagram shown in figure for a thermodynamic process

is a semicircle. Find the work done on the gas in the process

ABC.

(a) /2 atm-lt.

(b) /2 atm-lt.

(c) /4 atm-lt.

3

A

B

C

1 2

P(atm)

V(litre)

1

(d) None of these.

20. The two ends of a uniformly tapered rod are maintained at

temperatures 100C and 0C respectively. Under steady state,

the temperature of the sectionAA exactly at the mid point

(a) is more than 50C

(b) is 50C 0C

100CA

A

(c) is less than 50C

(d) none of these.

21. For the electric field

( ) !1/ 3E kx x="# Z

Y

X ll

l

l

where kis a constant, compute the electric flux throughthe face of the cubic region depicted in figure.

(a) 5/ 2 ( 2 1)kl (b) 3/ 2 ( 2 1)kl +(c) 3/ 2 ( 2 1)kl (d) 5/ 2 ( 2 1)kl +

22. For the electric field

( ) !1/ 3E kx x="#

where kis a constant, compute the charge confined

Z

Y

X ll

l

l

inside the cube?

(a) 5/ 20 ( 2 1)kl

(b) 3/20 ( 2 1)kl

(c) 3/20 ( 2 1)kl +

(d) 5/ 20 ( 2 1)kl + .


15/18

LOCUS 15


23. The region between two concentric spheres of radii a b< contains

volume charge density ( ) ,C

rr

= whereCis constant and ris the

radial distance, as shown in figure. A point charge q is placed at the

origin, r= 0.

Find the value ofCfor which the electric field in the region betweenthe spheres is constant.

(a) 24q

a(b) 2

3q

a

( )t r aq

b

(c) 22q

a(d) 2

q

a.

24. A solid insulating ball of radius a is surrounded by a conducting

spherical shell with an inner radius ofb and an outer radius of

c (see figure). The inner ball has a charge Q, which is uniformlydistributed throughout its volume. The conducting spherical

shell is charged with charge Q.

Compute the electric potential atP.

+Qa

b

c

Q

r1

(a)1 1

Qr b

+

(b)2 1

Qr b

(c)2 1

Qr b

+

(d)1 1

Qr b

.

25. A solid insulating ball of radius a is surrounded by a

conducting spherical shell with an inner radius ofb

and an outer radius ofc (see figure). The inner ball has

a charge Q, which is uniformly distributed throughout

its volume. The conducting spherical shell is charged

with charge Q.

Compute the electric potential atR.

+Qa

b

c

Q

Rr2

(a)1 1

Q

r b

(b)2 1

Q

r b

(c)1 1

Qr b

+

(d) zero.


16/18

LOCUS 16


26. A thin conducting plate is inserted in halfway between the plates of a parallel plates capacitor (see figure).

d/2

d/2

A (area of each plate)

Compute the capacitance before the plate was inserted.

(a)0 A

d

(b)

0

A

d

(c)02 A

d

(d)

03 A

d

.

27. A thin conducting plate is inserted in halfway between the plates of a parallel plates capacitor (seefigure).

d/2

d/2


What is the capacitance after the plate was inserted?

(a) 0 Ad (b) 0

A

d

(c)02 A

d

(d)

03 A

d

.

28. A thin conducting plate is inserted in halfway between the plates of a parallel plates capacitor (see

figure).

d/2

d/2


What does the value of capacitance become when the thin plate and the upper plate are shortened

(i.e. connected by a conducting wire)?

(a)0 A

d

(b)

0

A

d

(c)02 A

d

(d)

03 A

d

.


17/18

LOCUS 17


29. A capacitor is composed of two very long conducting

cylinders of radii a and b, where a < b. A constant

voltage difference Vis kept fixed across the capacitor

(see figure).

Compute the capacitance per unit length of the system.

ab

V+1=+Q

1= Q

(a) 0.5F(b) 1.5F

(c) 2F

(d) 2.5F.

30. A capacitor is composed of two very long conducting

cylinders of radii a and b, where a < b. A constant

voltage difference Vis kept fixed across the capacitor

(see figure).

a

b

V+1=+Q

1= Q

One adds a third concentric long conducting cylinder

of radius c, where c > b. Vis then turned off and its

positive terminal is reconnected to the new cylinderc.

What is the capacitance per unit length between the

cylinders of radii a and c?

(a)2 2

1 2

1( )

4C V V (b) 2 21 2

1( )

4C V V+

(c)2

1 2

1( )

4C V V (d) 21 2

1( )

4C V V+ .


18/18

LOCUS 18

PHYSICS1 (a) 11 (d) 21 (a)

2 (b) 12 (b) 22 (a)

3 (b) 13 (b) 23 (d)

4 (d) 14 (b) 24 (d)

5 (a) 15 (c) 25 (d)

6 (d) 16 (c) 26 (a)

7 (a) 17 (a) 27 (a)

8 (c) 18 (b) 28 (c)

9 (a) 19 (b) 29 (c)

10 (c) 20 (a) 30 (c)

ANSWERS

MATHEMATICS

DATE (8TH JANUARY,

2008)

1 (b) 11 (c) 21 (d)

2 (a) 12 (c) 22 (b)

3 (c) 13 (d) 23 (b)

4 (b) 14 (b) 24 (a)

5 (c) 15 (b) 25 (c)

6 (d) 16 (c) 26 (a)

7 (a) 17 (b) 27 (d)

8 (c) 18 (b) 28 (b)

9 (c) 19 (c) 29 (b)10 (b) 20 (d) 30 (c)

CHEMISTRY

1 (a) 11 (a) 21 (a)2 (b) 12 (b) 22 (a)

3 (d) 13 (d) 23 (a)

4 (a) 14 (d) 24 (c)

5 (d) 15 (a) 25 (b)

6 (c) 16 (c) 26 ( )

7 (b) 17 (a, d) 27 (b)

8 (d) 18 (b) 28 (a)

9 (c) 19 (c) 29 (d)

10 (b) 20 (b,c,d) 30 (b)

Documents

Cycle 2 Quize 3