bihar '13

7/21/2019 bihar '13

1/30

Physics1. The dimensions of universal gravitationalconstant are(a) [M L T2 3 2 ] (b) [M L T ]2 2 1

(c) [M L T1 3 2 ] (d) [ML T2 1 ]

2. If A B = 3 A B. then the value of A + Bis(a) A+B(b) (A B AB)/2 2 1 23+ +

(c) A B AB /

2 21 2

3+ +

(d) (A B AB)/2 2 1 2

+ +3. Two spheres of masses mandMare situated

in air and the gravitional force betweenthem is F. The space around the masses isnow filled with a liquid of specific gravity 3.The new gravitational force will be

(a) F (b) F3

(c) 3F (d) F9

4.A body floats in water with one fourth of itsvolume above the surface of water. Ifplaced in oil it floats with one third of itsvolume above the surface of oil. Thedensity of oil is

(a) 34

(b) 49

(c) 23

(d) 98

5. When capillary tubes of different radii ' 'rdipped in water, water rises to differentheights ' 'h in them, then(a) hr2 =constant (b) hr=constant

(c) hr

=constant (d) hr2

=constant

6. In the adjoining figure A, B, and Crepresents three progressive waves. Whichof the following statement about the wavesis correct?

(a) Wave C lags behind in phase by 2

from A and B

leads by 2

(b) Wave C leads in phase by from A and B lagsbehind by

(c) Wave Cleads in phase by 2

from A and lags behind

by 2

(d) Wave C lags behind in phase by from A and Bleads by

Solved Paper

2013

BCECEMedical Entrance Exam

B A

C

7/21/2019 bihar '13

2/30

7. If 110 J of heat are added to a gaseoussystem, whose internal energy is 40J, thenthe amount of external work done is(a) 40 J (b) 70 J(c) 110 J (d) 150 J

8.A ray is incident at an angle of incidence ionone surface of a prism of small angleAandemerges normally from the opposite surface.If the refractive index of the material of theprism is , the angle of incidence iis nearlyequals to(a) A/2 (b) A/2(c) A (d) A/

9.

Figure below shows four plates each of areaSseparated from one another by a distance d.What is the capacitance between AandB?

(a)4 0 3

d(b)

3 50d

(c) 2 50d

(d) 0 5d

10. What is the value of current in the armcontaining 2 resistor in the adjoiningcircuit?

(a) 0.7 amp (b) 1.2 amp(c) 1.5 amp (d) 1.0 amp

11. For ohmic conductor the drift velocity vd andthe electric field applied across it are related

as(a) v Ed (b) v Ed

2

(c) v Ed (d) v

Ed

1

12. If Eand Bbe the electric and magnetic fieldvectors of electromagnetic waves, the

direction of propagation of electromagneticwaves is that of

(a) E (b) B (c) E B (d) B E13. The current in RCL circuit is maximum

where(a) XL = 0 (b) X XL C=(c) XC = 0 (d) X XL C

2 2 1+ =

14. What is the value of A A+ in the booleanalgebra?(a) 0 (b) 1 (c) A (d)A

15. The truth table given below is for which gate?

A B

Y

0 0 1

0 1 1

1 0 1

1 1 0

(a) XOR (b) OR(c) AND (d) NAND

16. The magnetic flux through a circuit ofresistanceRchanges by an amount in atime t. Then the total quantity of electriccharge Qthat passes any point in the circuit

during the time tis represented by(a) Q

t=

(b) Q

R=

(c) Q Rt

= .

(d) QR t

= 1

17.A particle moves along a circle of radius20

mwith constant tangential acceleration.

If the velocity of the particle is 80 m/s at theend of the second revolution after motion hasbegun the tangential acceleration will be

(a) 40 m/s2 (b) 40m/s2(c) 160 m/s2 (d) 640 m/s2

18. The output of a OR gate is 1(a) if either input is zero(b) if both inputs are zero(c) only if both inputs are 1(d) if either or both inputs are 1

2 | BCECE(Medical)Solved Paper 2013

G

25 5

210

1.4A1.4A

BA

7/21/2019 bihar '13

3/30

19. Two 220V, 100W bulbs are connected firstin series and then in parallel. Each time thecombination is connected to a 220V ACsupply line, the power drawn by thecombination in each case respectively will be(a) 50 W, 200 W (b) 50 W, 20 W(c) 100 W, 50 W (d) 200 W, 150 W

20. Barrier potential of a p-njunction diode doesnot depend on(a) diode design (b) doping density(c) temperature (d) farward bias

21.A projectile is projected with a linearmomentum p making an angle with the

horizontal. The change in momentum of theprojectile on return to the ground will be(a) 2p tan (b) 2psin (c) 2pcos (d) 2p

22.A weigthtless thread can bear tension upto 3.7 kg wt. A stone of mass 500 g is tied toit and revolved in a circular path of radius4m in a vertical plane. If g= 10m/s2 , thenthe maximum angular velocity of the stonewill be(a) 2 rad/s (b) 4 rad/s(c) 16rad/s (d) 21 rad/s

23. Under a constant torque, the angularmomentum of a body changes fromAto 4Ain4 s. The torque is

(a) 3A (b) 14

A

(c) 34

A (d) 43

A

24. The mass of a planet is double and its radiusis half compared to that of earth. Assumingg= 10m/s2on earth, the acceleration due togravity at the planet will be

(a) 10 m/s2

(b) 20 m/s2

(c) 40 m/s2

(d) None of these

25.A soap bubble in vacuum, has a radius of3 cm and another soap bubble in vacuumhas a radius of 4 cm. If the two bubbles

coalesce under isothermal condition, thenthe radius of new bubble is

(a) 4.3 cm (b) 4.5 cm (c) 5 cm (d) 7 cm26. Deuteron and -particle are put 1 apart in

air. Magnitude of intensity of electric fielddue to deuteron of -particle is(a) zero (b) 2 88 1011. N/C(c) 144 1011. N/C (d) 576 1011. N/C

20. The air column in pipe, which is closed atone end will be in resonance with a vibratingturning fork at a frequency of 260 Hz, if thelength of the air column is(a) 31.73 cm (b) 62.5 cm(c) 35.75 cm (d) 12.5 cm

28. A ball strikes against the floor and returnswith double the velocity. In which type ofcollision is it possible?(a) Inelastic (b) Perfectly inclastic(c) Perfectly elastic (d) Not possible

29.A body is under the action of three forceF1,F2,and F3. In which case the body cannot undergo angular acceleration?(a) F F F1+ + =2 3 0(b) F1, F2and F3are concurrent(c) F1, andF2act at the same point but,F3acts at different

point(d) F F1 2+ is parallel to F3, but the three forces are not

concurrent

30. Two beams of protons moving parallel insame direction will(a) repel each other(b) exert no force(c) attract each other(d) deflect perpendicular to the plane of the beams

31.A photon and an electron possess samede-Broglie wavelength given that C= speedof light and v= space of electron, which of

the following relation is correct?(here, E K Ee= . of electron, E K EPh = . ofphoton, Pe= momentum of electron, Pph=momentum of photon )

(a) PP

C

ve

Pn

=2

(b) EE

C

ve

Ph

=2

(c)E

E

c

v

ph

e

= 2 (d) PP

c

ve

Ph

= 2

BCECE (Medical)Solved Paper 2013 | 3

7/21/2019 bihar '13

4/30

32. To get an output Y= 1 from circuit ofadjoining figure, the input must be

A B C

(a) 0 1 0(b) 1 0 0(c) 1 0 1(d) 1 1 0

33. Hubbles law is expressed as

(here, v= speed of recession, r= distance of

galaxy,H=hubble constant)(a) v Hr= (b) v H r= 2

(c) v H

r=

2(d) v Hr= 2

34. The displacement versus time graph for abody moving in a straight line is shown infigure. Which of the following regionsrepresents motor when no force is acting onthe body?

(a) ab (b) bc(c) cd (d) be

35. Which of the following graphs shows thevariation of magnetic fieldB, with distancefrom a long current carrying conductor?

36. The time period of a freely suspendedmagnet does not depend upon

(a) length of the magnet(b) the pole strength of the magnet(c) the horizontal component of magnetic field of

earth(d) the length of the suspension

37. The magnetic permeability is defined as theratio of(a) magnetic induction and magnetising field(b) intensity of magnetisation and magnetising field(c) intensity of magnetisation and magnetic field(d) None of the above

38. Figure represents an area A= 05 2. m

situated in a uniform magnetic fieldB = 20. Wb/m2 and making an angle of 60with respect to magnetic field. The value ofmagnetic flux through the area will be

(a) 0.5 Wb (b) 3Wb(c) 3

2Wb (d) 2 0. Wb

39. Of the given diodes, shown in the adjoiningdiagrams, which one is reverse biased?

40. Three particles each of mass m gram, aresituated at the vertices of an equilateraltriangle ABCof the side 1 cm. The moment


A

60

r

B

r

B

r

B

r

B

(a) (b)

(c) (d)

b

c

d

e

at

S

A

B

C

Y

R

10 V

R

+5 V

(a)

(b)

5 V

+10 V

(c)

(d)

12 V

+5 V

7/21/2019 bihar '13

5/30

of inertia of the system (as shown in figure)about a lineAXperpendicular toABand inthe plane ofABCin gram-cm2units will be

(a) 32ml2 (b) 3

4ml2

(c) 2ml2 (d) 54

ml2

41.A galvanometer of 50 resistance has 25divisions. A current of 4 10 4 A gives adeflection of one division. To convert thisgalvanometer into a voltmeter having arange of 25 volt, it should be connected witha resistance of(a) 245as shunt (b) 2450as series(c) 2500as shunt (d) 2550in series

42.A car is moving towards a high cliff. The cardriver sounds a horn of frequency f. Thereflected sound heard by the driver has the

frequency 2f. If v be the velocity of sound,then the velocity of the car, in the samevelocity units will be

(a) v2

(b) v2

(c) v3

(d) v4

43. A plane glass slab is kept over variouscoloured letters, the letter which appearsleast raised is(a) violet (b) blue(c) green (d) red

44. If the angle of incidence is i and that ofrefraction is r. Then the speed of light in themedium to which the light is refracted fromair is

(a) v C ir

= sincos

(b) v C ri

= coscos

(c) v C r

i= sin

sin(d) v C i

r= sin

sin

45.An electron moves with a velocity v in anelectric field E. If the angle between vand Eis neither 0 nor , the path followed by theelectron is(a) parabola (b) circle(c) straight line (d) ellipse

46. The internal resistance of a cell of emf 2 V is01. . If it is connected to a resistance of 3 9. ,then the voltage across the cell will be (involts)

(a) 2 V (b) 0.5 V(c) 195. V (d) 2 5. V

47. An electric kettle takes 4 A current a t 220 V.How much time will it take to boil 1 kg ofwater from room temperature 20C? (thetemperature of boiling water is 100C)(a) 12.6 min (b) 12.8 min(c) 6.3 min (d) 6.4 min

48. The phenomenon of pair production is(a) ejection of an electron from a nucleus(b) ejection of an electron from a metal surface

(c) ionisation of a neutral atom(d) the production of an electron and a positron from

-rays.

49. In an electron microscope if the potential isincreased from 20kV to 80 kV, the resolvingpowerRof the microscope will become

(a) R2

(b) 2R

(c) 4R (d) 5R

50. Force acting upon a charged particle keptbetween the plates of changed capacitor isF.

If one of the plates of the capacitor isremoved force acting on the same particlewill become(a) 0 (b) F(c) F

2(d) 2 F


C

Bm

mmA l

ll

X

7/21/2019 bihar '13

6/30

Chemistry

1. CH C

CH

CH

CH

OH

CH A3

3

3

3HBr

(Predominant)

IdentifyA.(a) (CH ) C (Br) CH (CH )3 2 3 2(b) (CH ) CCH (Br) CH3 3 3(c) (CH ) COHBr CH3 3 3(d) None of the above

2.A -hydroxy carbonyl compound is obtainedby the action ofNaOHon

(a) C H CHO6 5 (b) HCHO(c) CH CHO3 (d) (CH ) C CHO3 3

3. Which of the following statements is correct?(a) + Ieffect stabilises a carbanion(b) + Ieffect stabilises a carbocation(c) Ieffect stabilises a carbanion(d) Ieffect stabilises a carbocation

4. C H O C H O4 6 4 3 6 2sodalime

A B

C

Compound C is a hydrocarbon, occupying

approx 0.75 L volume per gram. Identify Aand B.(a) Tartaric acid, propanoic acid(b) Succinic acid, succinic anhydride(c) Maleic anhydride, maleic acid(d) Methyl malonic acid, propanoic acid

5. What is effective nuclear charge and theperiphery of nitrogen atom when an extraelectron is added in the formation of ananion?(a) 1.20 (b) 2.45

(c) 3.55 (d) 5.95

6.A certain metal sulphide, MS2 , is usedextensively as a high temperature lubricant.If MS2 has 40.06 % sulphur by weight,atomic mass ofMwill be(a) 100 amu (b) 96 amu(c) 60 amu (d) 30 amu

7. In HNC, which element has least value offormal charge?(a) H (b) N(c) C (d) All have same value

8. Consider following unit values of energy

I. 1 L atm, II. 1 erg,III. 1 J IV. kcal,Increasing order of these values is(a) I = II = III = IV (b) I < II < III < IV(c) II < III < I < IV (d) IV < I < III < II

9. The number of elements in the transitionmetal series Sc through Zn that have fourunpaired electrons in their + 2 state are(a) 2 (b) 4(c) 5 (d) 6

10. In an atmosphere with industrial smog,copper corrodes to

I. Cu (OH) SO2 2 4 II. Cu (OH) CO2 2 3

III. CuSO4 IV. CuCO3(a) I and III(b) II and IV(c) I and IV(d) I and II

11. Mischmetal is(a) an alloy of lanthanide and nickel(b) an alloy of lanthanide and copper(c) an alloy of lanthanide, iron and carbon(d) an alloy of lanthanide, magnesium and nickel

12. What is the oxidation state of iron in[Fe(H O) NO]2 5

2+?(a) 0 (b) + 1

(c) + 2 (d) + 3

13. Identify the final product of the reaction

BCl + NH Cl3 4C H Cl

140 C NaBH

6 5

4

?

(a) B N H3 3 6 (b) B H2 6(c) NaBCl4 (d) BN


7/21/2019 bihar '13

7/30

14. 2.56 g of sulphur in 100 g of CS2 hasdepression in freezing point of 0.010C.

Atomicity of sulphur in CS2is(Given, Kf= 0.1 molal )1

(a) 2 (b) 4(c) 6 (d) 8

15. For the zeroth order reaction, sets I and IIare given, hencexis

(a) 2 min (b) 4 min(c) 6 min (d) 8 min

16. Equilibrium constant for the reaction,

NH OH + H NH + H O4+

4+

2 is 1.8 109.

Hence, equilibrium constant forNH (aq) + H O NH + OH3 2 4+

is

(a) 1.8 10 5 (b) 1.8 105(c) 1.8 10 9 (d) 5.59 10 10

17. Calculate pH change when 0.01 molCH KCOO Na3 solution is added to 1 L of001. M CH COOH3 solution.

Ka(CH COOH) 1.8 1035= , pKa = 4.74

(a) 3.37 (b) 1.37(c) 4.74 (d) 8.01

18. pKbofNH3is 4 74. andpKbofA B , and Care 4, 5 and 6 respectively. Aqueous solutionof 0.01 M haspH in the increasing order(a) NH < NH < NH4 4 4A B C(b) NH < NH < NH4 4 4C B A(c) NH < NH < NH4 4 4C A B(d) All have equal pH

19. Osmotic pressure of insulin solution at298 K is found to be 0.0072 atm. Hence,height of water column due to this pressureis [given (Hg) 13.6 g / mL]d =(a) 0.76 cm (b) 0.70 cm(c) 7.4 cm (d) 76 cm

20.G and H for a reaction at 300 K is 66.9 kJ mol 1 and 41.8 kJ mol 1

respectively. G for the same reaction at330Kis(a) 25.1 kJ mol 1

(b) + 25.1 kJ mol 1

(c) 18.7 kJ mol 1

(d)

69.4 kJ mol1

21.At 1000 K, from the data

N ( ) 3H ( ) 2NH ( )2 2 3g g g+ ;

H= 123.77 kJ mol 1

Substance N2 H2 NH3

P R/ 3.5 3.5 4

Calculate the heat of formation of NH3 at300 K.

(a)

44.42 kJ mol

1

(b) 88.85 kJ mol 1

(c) + 44.42 kJ mol 1

(d) + 88.85 kJ mol 1

22. Match the electrode (in column I) with itsgeneral name (in Column II) and choose thecorrect option given below.

Column I Column II

A. Calomel I. Reference

B. Glass II. Redox

C. Hydrogen III. Membrane

D. Quinhydrone IV. Gas

A B C D(a) I II III IV(b) I III IV II(c) III II IV I(d) II IV III I


I.

II.

t = 0t = 2 min

t = 0 t = x min

7/21/2019 bihar '13

8/30

23. In a Daniell cell constructed in thelaboratory, the voltage observed was 0.9 Vinstead of 1.1 V of the standard cell. Apossible explanation is(a) [Zn ] > [Cu ]2 + 2 +

(b) [Zn ] < [Cu ]2 + 2 +

(c) Zn electrode has twice the surface of Cu electrode

(d) mol ratio of Zn : Cu2 + 2 +is 2 : 1

24.A quantity of electrical charge that bringsabout the deposition of 4.5 g Al from Al3 +atthe cathode will also produce the followingvolume at (STP) of H2 (g) from H

+ at thecathode(a) 44.8 L (b) 22.4 L(c) 11.2 L (d) 5.6 L

25. IUPAC name of the following compound is

(a) 3-propyl cyclo [3, 6] octane(b) 1-ethyl tricyclo [2, 3, 0] heptane(c) 1-ethyl bicyclo [2, 2, 1] heptane

(d) 4-ethyl bicyclo [2, 2, 2] heptane26. Identify Yin the following series of equation

H + Br2hv

X D O

Mg/ ether

2

Y

(a) Br D (b) D(c) Br D (d)

D

Br

27.Arrange the following in the order of rate ofoxidation with periodic acid

I. HOCH CH OH2 2 ,II. CH CHOHCHOHCH3 3III. (CH ) COHCOH (CH )3 2 3 2

(a) I > II > III (b) II > I > III(c) III > II > I (d) I > III =II

28. Phenol and NH3reacts in presence of ZnCl2at 300C to produce

(a) tertiary amine (b) secondary amine(c) primary amine (d) All of these

29.A [C H O (keto ester)6 10 3NaOH + I2

]

yellow

ppt +

B CH

+

CO3

2

CH COOH

.

Hence, Ais

(a) CH C

O

CH C

O

OC H3 2 2 5

(b) CH CH C

O

CH C

O

OCH3 2 2 3

(c) Both are correct (d) None is correct

30. CH CH3 3CO

can be converted into CH OH3CO

by following methods

I. CH CH3 3H

I / NaOH

+

2C

O

,

II. CH CH3 3Cr O / H2 7

2 +

C

O

III. CH CH3 3Ag(NH )3 2

+

C

O

Which method are most effective?(a) I, III (b) II, III(c) I, II (d) I, II, III

31. Relative stabilities of the followingcarbocation will be in order

(a) I V < III < II < I (b) I V < II < III < I(c) I I < IV < III < I (d) I < II < III < IV


CH CH2 3

CH O3 CH2

I

CH2

II

CH3 CH2

III

CH CH3 2

IV

7/21/2019 bihar '13

9/30

32. The correct statement in respect of proteinhaemoglobin is that it

(a) functions as a catalyst for biological reactions(b) maintains blood sugar level(c) acts as an oxygen carrier in the blood(d) forms antibodies and offers resistance to diseases

33. CH COOH + HCOOH3570 K

MnO

Main product of above reaction is(a) CH CHO3 (b) CH COCH3 3(c) HCHO (d) (CH CO) O3 2

34.Aniline is reacted with bromine water andthe resulting product is treated with an

aqueous solution of sodium nitrite inpresence of dilute hydrochloric acid. Thecompound so formed is converted to atetrafluoroborate which is subsequentlyheated. The final product is(a) p-bromoaniline(b) p-bromofluorobenzene(c) 1, 3, 5-tri bromobenzene(d) 2, 4, 6-tribromofluorobenzene

35. With hard water, ordinary soap forms curdyprecipitate of(a) (RCOO) Ca2 (b) (RCOO) Mg2

(c) Both (a) and (b) (c) None of these36. Which is matched incorrectly?

Structure Compound(a)

(b)

(RCOO) Mg2 Coumarin

(c) Both (a) and (b)(d) None of the above

37. Which base is normally found in RNA butnot in DNA?(a) Uracil(b) Thymine(c) Guanine(d) Adenine

38. The dipole moment of HBr is2.60 10 30 cmand the interatomic spacing is 1.41. Whatis the per cent ionic character of HBr?(a) 50% (b) 11.5% (c) 4.01% (d) 1.19%

39.An element is oxidised by fluorine and notby chlorine. Identify the element.(a) Sodium (b) Aluminium(c) Oxygen (d) Sulphur

40. The reduction of an oxide by aluminium iscalled(a) Krolls process(b) van Arkel process(c) Ellingham process(d) Goldschmidts aluminothermite process

41. H2 gas is liberated at cathode and anodeboth by electrolysis of the following solutionexcept in(a) NaCl (b) NaH(c) LiH (d) HCOONa

42. Identify ( )A and ( )B in the followingsequence of reactions.

SnCl + 2NaOH ( ) (white ppt)2 A

(excess)

NaOH( )B

(a) Sn(OH) , Na SnO2 2 3(b) Sn(OH)2, Na SnO2 2(c) Sn(OH) , Na [Sn(OH) ]2 2 6(d) Sn(OH) ,2 no effect

43. Nature of nitride ion is(a) acidic (b) basic(c) amphiprotic (d) cannot predict

44. Wave number of spectral line for a giventransition isx cm 1 for He+ , then its valuefor Be3 + (isoelectronic of He+) for sametransition is

(a) x4

cm 1 (b) x cm 1

(c) 4 cm 1x (d) 16 cm 1x

45. H O2 2 oxidises MnO2 is MnO4 in basic

medium, H O2 2 and MnO2react in the molarratio of(a) 1 : 1 (b) 2 : 1 (c) 2 : 3 (d) 3 : 2


O

HO OH

CH (OH) CH OH2 Ascorbic acid

O O

7/21/2019 bihar '13

10/30

46. 25 mL of an aqueous solution of KCl wasfound to require 20 mL of 1 M AgNO3solution when titrated using a K CrO

2 4 as

indicator. Depression in freezing point ofKCl solution with 100% ionisation will be[KF 2.0 mol kg

1= , molarity =molality](a) 3.2 (b) 1.6(c) 0.8 (d) 5.0

47. Out of the following, select Lux-Flood Acid(a) CO2 (b) BF3(c) H+ (d) Al(CH )3 3

48. On adding AgNO3solution into KI solution,a negatively charged colloidal sol. is

obtained when they are in(a) 100 mL of 0.1 M AgNO + 100 mL3 of 0.1 M KI

(b) 100 mL of 0.1 M AgNO +100 mL3 of 0.2 mKI

(c) 100 mL of 0.2 M AgNO + 100 mL3 of 0.1 M KI

(d) 100 mL of 0.15 M AgNO + 100 mL3 of 0.15 M KI

49. Graph between log x

m

and log p is a

straight line at angle 45 with intercept OA

as shown. Hence,x

m

at a pressure of

0.2 atm is

(a) 0.8 (b) 0.6(c) 0.4 (d) 0.2

50. From the following reactions at 298 K,(A) CaC ( ) + 2H O ( ) Ca(OH) ( )2 2 2s l s

+ C H ( ) DH (kJ mol ) 127.92 21g

(B) Ca ( ) 1

2

O ( ) CaO( ) 635.12s g s+

(C) CaO ( ) H O ( ) Ca(OH) ( )2 2s I s+ 65.2

(D) C ( ) O ( ) CO ( ) 393.52 2s s s+

(E) C H ( )52

O ( ) 2CO ( )2 2 2 2g g g+

+ H O ( ) 1299.582 e

Calculate the heat of formation of CaC ( )2 s at298 K.(a) 59.82 KJ mol1 (b) + 59.82 KJ mol1

(c) 190.22 KJ mol1 (d) +190.22 KJ mol1

Biology

1. Pineapple (annanas) fruit develops from(a) a unilocular polycarpellary flower(b) a multipistillate syncarpous flower(c) a cluster of compactly borne flowers on a common

axis(d) a multilocular monocarpellary flower

2. Parthenocarpic tomato fruits can be

produced by(a) removing androecium of flowers before pollen grains

are released(b) treating the plants with low concentrations of

gibberellic acid and auxins(c) raising the plants from vernalized seeds(d) treating the plants with phenylmercuric acetate

3. The blue baby syndrome results from(a) excess of chloride(b) methaemoglobin(c) excess of dissolved oxygen(d) excess of TDS (Total Dissolved Solids)

4. Which one of the following statements iscorrect?(a) Neurons regulate endocrine activity, but not vice versa(b) Endocrine glands regulate neural activity and

nervous system regulates endocrine glands(c) Neither hormones control neural activity nor the

neurons control endocrine activity(d) Endocrine glands regulate neural activity, but not

vice versa


45A0.3010

logxm

logp

7/21/2019 bihar '13

11/30

5. Farmers in a particular region wereconcerned that pre-mature yellowing ofleaves of a pulse crop might cause decreasein the yield. Which treatment could be mostbeneficial to obtain maximum seed yield?(a) Frequent irrigation of the crop(b) Treatment of the paints with cytokinins along with a

small dose of nitrogenous fertiliser(c) Removal of all yellow leaves and spraying the

remaining green leaves with 2, 4, 5-trichlorophenoxyacetic acid

(d) Application of iron and magnesium to promotesynthesis of chlorophyll

6. Which one of the following amino acids wasnot found to be synthesised in Millers

experiment?(a) Glycine (b) Aspartic acid(c) Glutamic acid (d) Alanine

7. Crop plants grown in monoculture are(a) low in yield(b) free from intraspecific competition(c) characterised by poor root system,(d) highly prone to pests

8. The formula for exponential populationgrowth is(a) dt dN rN/ = (b) dN rN dt / =(c)rN dN dt/ = (d) dN dt rN/ =

9. In photosystem-I, the first electron acceptoris(a) ferredoxin (b) cytochrome(c) plastocyanin (d) an iron-sulphur protein

10. Which one of the following is the mostsuitable, medium for culture of Drosophilamelanogaster?(a) Moist bread (b) Agar agar(c) Ripe banana (d) Cow dung

11. Which antibiotic inhibits interactionbetween rRNA and mRNA during bacterialprotein synthesis?(a) Erythromycin(b) Neomycin(c) Streptomycin(d) Tetracycline

12. Photochemical smog pollution does notcontain

(a) ozone(b) nitrogen dioxide(c) carbon dioxide(d) PAN (Peroxy Acyl Nitrate)

13. The thalloid body of a slime mould(Myxomycetes) is known as(a) protonema (b) Plasmodium(c) fruiting body (d)mycelium

14. What type of placentation is seen in sweetpea?(a) Basal (b) Axile

(c) Free central (d) Marginal

15. Long filamentous threads protruding at theend of a young cob of maize are(a) anthers (b) styles(c) ovaries (d) hairs

16. How many different kinds of gametes will beproduced by a plant having the genotype

AABbCC?(a) Three (b) Four(c) Nine (d) Two

17. Which of the following statements regardingmitochondrial membrane is not correct?(a) The outer membrane is permeable to all kinds of

molecules(b) The enzymes of the electron transfer chain are

embedded in the outer membrane(c) The inner membrane is highly convoluted forming a

series of infoldings(d) The outer membrane resembles a sieve

18.An organic substance bound to an enzymeand essential for its activity is called(a) coenzyme (b) holoenzyme

(c) apoenzyme (d) isoenzyme

19. Bowmans glands are found in(a) olfactory epithelium(b) external auditory ca.ial(c) cortical nephrons only(d) juxtamedullary nephrons


7/21/2019 bihar '13

12/30

20. The bacterium (Clostridium botulinum)that causes botulism is

(a) a facultative anaerobe(b) an obligate anaerobe(c) a facultative aerobe(d) an obligate aerobe

21. Sulphur is an important nutrient foroptimum growth and productivity in(a) pulse crops (b) cereals(c) fibre crops (d) oilseed crops

22. In a moss the sporophyte(a) is partially parasitic on the gametophyte(b) produces gametes that give rise to the gametophyte

(c) arises from a spore produced from thegametophyte(d) manufactures food for itself, as well as for the

gametophyte

23. Curing of tea leaves is brought about by theactivity of(a) bacteria (b) mycorrhiza(c) viruses (d) fungi

24.Annual migration does not occur in the caseof(a) salmon (b) Siberian crane(c) salamander (d) arctic tern

25.A major break through in the studies of cellscame with the development of electronmicroscope. This is because(a) the resolution power of the electron microscope is

much higher than that of the light microscope(b) the resolving power of the electron microscope is

200 - 350 nm as compared to 0.1 - 0.2 nm for the lightmicroscope

(c) electron beam can pass through thick materials,whereas light microscopy requires thin sections

(d) the electron microscope is more powerful than thelight microscope as it uses a beam of electronswhich has wavelength much longer than that of

photons

26. Metameric segmentation is thecharacteristic of(a) Platyhelminthes and Arthropoda(b) Echinodermata and Annelida(c) Annelida and Arthropoda(d) Mollusca and Chordata

27. What is common about Trypanosoma,Noctiluca, Monocystis andGiardia?

(a) These are all unicellular protists(b) They have flagella(c) They produce spores(d) These are all parasites

28. Evolutionary history of an organism isknown as(a) Phylogeny (b) Ancestry(c) Paleontology (d) Ontogeny

29. Which of the following is considered ahot-spot of biodiversity in India ?

(a) Western ghats (b) Indo-Gangetic plain(c) Eastern ghats (d) Aravalli hills

30. Which one of the following is an example ofpolygenic inheritance?(a) Flower colour in Mirabilis jalapa(b) Production of male honey bee(c) Pod shape in garden pea(d) Skin colour in humans

31. Which one of the following not act as aneurotransmitter ?

(a) Acetylcholine (b) Epinephrine(c) Nor epinephrine (d) Cortisone

32.A steroid hormone which regulates glucosemetabolism is(a) cortisol(b) corticosterone(c) 11-deoxycorticosterone(d) cortisone

33. Which one of the following is not a secondmessenger in hormone action?(a) cGMP (b) Calcium (c) Sodium (d) cAMP

34. In Mendels experiments with garden pea,round seed shape (RR) was dominant overwrinkled seeds (IT), yellow cotyledon (YY)was dominant over green cotyledon (yy).What are the expected phenotypes in the F2generation of the cross RRYY x rryy?(a) Only round seeds with green cotyledons(b) Only wrinkled seeds with yellow cotyledons(c) Only wrinkled seeds with green cotyledons(d) Round seeds with yellow cotyledons and wrinkled

seeds with yellow cotyledons


7/21/2019 bihar '13

13/30

35. One turn of the helix in a B-form DNA isapproximately

(a) 20 nm (b) 0.34 nm(c) 3.4 nm (d) 2 nm

36.Antiparallel strands of a DNA moleculemeans that(a) one strand turns anti-clockwise(b) the phosphate groups of two DNA strands, at their

ends, share the same position(c) the phosphate groups at the start of two DNA strands

are in opposite position (pole)(d) one strand turns clockwise

37. Mast cells secrete(a) hippurin (b) myoglobin

(c) histamine (d) haemoglobin

38. If a colourblind woman marries a normalvisioned man, their sons will be(a) all normal visioned(b) one-half colourblind and one-half normal(c) three-fourths colourbling and one-fourth normal(d) all colourblind

39.Antibodies in our body are complex(a) lipoproteins (b) steroids(c) prostaglandins (d) glycoproteins

40. Limit of BOD prescribed by Central

Pollution Control Board for the discharge ofindustrial and municipal waste water intonatural surface water, is(a) < 3 0. ppm(b) < 10 ppm(c) < 100 ppm(d) < 30ppm

41. Earthworms are(a) ureotelic when plenty of water is available(b) uricotelic when plenty of water is available(c) uricotelic under conditions of water scarcity(d) ammonotelic when plenty of water is available

42. Withdrawal of which of the followinghormones is the immediate cause ofmenstruation?(a) Oestrogens(b) FSH(c) FSH-RH(d) Progesterone

43. Which one of the following statements isincorrect?

(a) The residual air in lungs slightly decreases theefficiency of respiration in mammals(b) The presence of non-respiratory air sacs, increases

the efficiency of respiration in birds(c) In insects, circulating body fluids serve to distribute

oxygen to tissues(d) The principle of countercurrent flow facilitates

efficient respiration in gills of fishes

44. The translocation of organic solutes in sievetube members is supported by(a) root pressure and transpiration pull(b) P-proteins(c) mass flow involving a carrier and ATP(d) cytoplasmic streaming

45.An enzyme that can stimulate germinationof barley seeds is(a) -amylase (b) lipase(c) protease (d) invertase

46. In a cereal grain the single cotyledon ofembryo is represented by(a) coleorhiza (b) scutellum(c) prophyll (d) coleoptile

47. The majority of carbon dioxide produced byour body cells is transported to the lungs

(a) dissolved in the blood(b) as bicarbonates(c) as carbonates(d) attached to haemoglobin

48. In order to obtain virus-free plants throughtissue culture the best method is(a) protoplast culture (b) embryo rescue(c) anther culture (d) meristem culture

49. Sickle-cell anaemia has not been eliminatedfrom the African population because(a) it is controlled by recessive genes(b) it is not a fatal disease

(c) it provides immunity against malaria(d) it is controlled by dominant genes

50. Both sickle-cell anaemia and Huntingtonschorea are(a) bacteria-related diseases(b) congenital disorders(c) pollutant-induced disorders(d) virus-related diseases


7/21/2019 bihar '13

14/30

Answers

Physics

Chemistry

Biology

1. (c) 2. (d) 3. (a) 4. (d) 5. (b) 6. (a) 7. (b) 8. (c) 9. (c) 10. (d)

11. (c) 12. (c) 13. (b) 14. (b) 15. (d) 16. (b) 17. (b) 18. (d) 19. (a) 20. (a)

21. (b) 22. (b) 23. (c) 24. (d) 25. (b) 26. (c) 27. (a) 28. (d) 29. (b) 30. (c)

31. (c) 32. (c) 33. (a) 34. (b) 35. (c) 36. (d) 37. (a) 38. (a) 39. (b) 40. (d)

41. (b) 42. (c) 43. (d) 44. (c) 45. (a) 46. (c) 47. (c) 48. (d) 49. (b) 50. (c)

1. (a) 2. (c) 3. (b) 4. (d) 5. (c) 6. (b) 7. (c) 8. (c) 9. (a) 10. (d)

11. (c) 12. (b) 13. (a) 14. (d) 15. (c) 16. (a) 17. (b) 18. (b) 19. (c) 20. (d)

21. (a) 22. (b) 23. (a) 24. (d) 25. (c) 26. (b) 27. (a) 28. (v) 29. (a) 30. (c)31. (b) 32. (c) 33. (a) 34. (d) 35. (c) 36. (d) 37. (a) 38. (b) 39. (c) 40. (d)

41. (b) 42. (b) 43. (b) 44. (c) 45. (d) 46. (a) 47. (a) 48. (b) 49. (a) 50. (a)

1. (c) 2. (b) 3. (b) 4. (a) 5. (d) 6. (c) 7. (d) 8. (d) 9. (d) 10. (c)

11. (d) 12. (c) 13. (b) 14. (d) 15. (b) 16. (d) 17. (b) 18. (a) 19. (a) 20. (b)

21. (a) 22. (a) 23. (a) 24. (c) 25. (a) 26. (c) 27. (a) 28. (a) 29. (a) 30. (d)

31. (d) 32. (a) 33. (c) 34. (d) 35. (c) 36. (c) 37. (c) 38. (d) 39. (d) 40. (b)

41. (d) 42. (d) 43. (a) 44. (c) 45. (a) 46. (b) 47. (d) 48. (d) 49. (b) 50. (b)

7/21/2019 bihar '13

15/30

Hints & Solutions

Physics

1. F Gm m

r= , 22

G Frm m

=2

1 2 =

[MLT ][L ]

[M ]

2 2

2

= [M L T ]1 3 2

2. Given, A B A B = 3 .

AB AB cossin = 3

tan = 3 or = 60

Hence, A B+ = + +A B AB2 2 2 cos

= + + A B AB2 2 2 60cos

= + +A B AB2 2 2 12

= + +( )/A B AB2 2 1 2

3. The gravitational force will remain the same asit is independent of density of medium.

4. Let the volume of the body be Vand densitybe d . Then for the case of water

V d g v d g =

3

4 water

For oil V d g V d g = 23 oil

dd

oil

water= 9

8

5. We have,hr g

= 2 cos

h r. =constant6. According to the given figure,Aattains mean

position T/4 time earlier than C. So, C lags

behind A by

2

. Also B attains the mean

positionT

2time earlier.

Hence, BleadsAby2

.

7. We have, Q = + U W

Here, Q= 110 J, U= 40 J W= 70 J

8. For a small angle prism, = ( )u A 1 ...(i)

Since, the ray emerges normally, e= 0By the relation,

A i e+ + =We have, i A= + or 6 = ( )i A ...(ii)From Eqs. (i) and (ii)

(i A ) = ( ) i A

i A= 9. Two plates of B are joined together and

therefore cannot form a capacitor. Thus, thereare only two capacitors in parallel onebetween the upper most plate and the nextone and second between the lower most plateand the one above it.

Hence, C C Cd d d

= + = + =1 2 0 0 05 5 2 5

10. As the given condition is of balanced wheatstone bridge.

I I1 112 14 30 = ( . ) I1 42 14 30 = .

14 3042

1. = A.

11. We have I ne Av d=

and I V

R=

VR

ne A vd=

or V ne A v Rd= .

=

neA v

l

Ad

Vl

E ne lv d= =

E vd12. Poynting vector which is in the direction of

travel of electromagnetic wave is along thevector E B .


7/21/2019 bihar '13

16/30

13. The current an a LCR circuit is given as

I E t

R X XL C

=

+

02 2

sin(

( )

)

Current is maximum if,R X XL C

2 2+ ( ) =minimum

X XL C = 0or X XL C=

14. A A+ should always be equal to one asaddition of quantity like 1 to 0 or 0 to 1 alwaysgives 1.

15.The given truth table is of NAND gate.

16. We have, et

=

Current, I eR

= = R

So, charge Q I t= . =

Rt. =

R

17.We have,2 2 2= +u as

( ) ( )80 0 2 4 202 = +

a

[as two revolutions are completed] a= 40 2m s/

18. The output of a OR gate is

= +A B

19.In series, power, P V

R=

2

2 =P

2=50 W

In parallel, power, P V

R=

2

2

= 2P=20 W

20.Barrier potential of a p-njunction diode doesnot depend on diode design.

21.( )P Pf i = Change in momentum

= + + P P P P2 2 2 2. cos ( )

= + P 2 2( cos ) =P 2 2 2( sin )

= 2P sin

22.Maximum tension = +mvr

mg2

37 10. = + 0 54 0 5 102

. .v

v m s= 16 /

= = =vr

164

4 rad/s

23.Change in angular momentum =Torque time

Torque = 44

34

A AA

=

24. By the relation,g GM

R= 2 we have

g

gP

e

= M

M

R

R

p

e

e

p

2

2 = 2 22( )

gp= =8 10 802m s/

25. Total volume is conserved.

43

343

43 3

( ) ( )+ = 43

3 R

or R 45. cm

26. (b) E q

n= 9 109

=

=

9 1016 101 10

144 10919

10 211.

( ). M/C

27.For Q, closed pipe.n K C= +( ) /2 1 4

for K= 0, it givesL= 1 10 330 4 2602( ) /

= 317. cm28.This is not possible as it is against the law of

conservation of energy.

29. Only if the three forces are concurrent, theycannot produce a net clockwise oranticlockwise momentum, which isneccessary for rotation.

30. Moving beams of protons are like currents.Two parallel currents attaract each other.

31. We have , PhPh

hP= and e e

hP=

Given, Ph e=We get, P PPh e=

h

mvPh =


q

7/21/2019 bihar '13

17/30

hc

Ph= =

mcv mv

c

v

12

22

orE

E

c

vPhe

=2

32. Y= 1, ifA= 1, B= 0 andC= 1becauseAand Bare input of OR gate and the output ofAandB and as well as C are the inputs of ANDgate.

33. We have, v r v Hr=where, His Hubble's" constant.

34.Slope of displacement versustime graph givesthe velocity. This is constant here only duringthe bc, as the graph is a straight line in it.

Constant velocity means no acceleration,35. For a long conductor, magnetic field at

distanceris

B I

r

I

r= =

0 0

42

2

Br

1

So, graph between B and r should be aparabola as given in option (c).

36. Time period is given by, T I

MH= 2

Hence, it does not depend upon the length ofthe suspension.

37. We have, B H=

=BH

So, the permeability is defined as the ratio ofmagnetic induction to the magnetising field.

38. As = B A.

= 2 0 5 60 . cos

= 2 0 5 12

. , = 0 5. Wb

39. In the diagram (b), the positive terminal is atlower potential and negative terminal is athigher potential, hence it is reversedbiased.

40. Moment of inertia of the system I I I I= + +1 2 3

= +

+02

22m

lml

= +ml ml2

2

4

=54

2ml

41. Given Rg = 50,

Ig= = 25 4 10 104 2A A

Range of V= 25 volts

Resistance, R V

IR

gg= =

2510

502

= 2450Thus, a resistance of 2450 is connected isseries to convert it into a voltmeter.

42. We have, = +

v v

v v

s

s

or 2f v v

v vfs

s

= +

or 2( )v v v v s s = +or 2 2v v v v s s = +

v vs= 3 or v v

s= 343.Rise =Real depth-apparent depth

=R D. R D.

=

R D. 11

Thus, for least rise should be least.

Refractive index is least for red colour.44. We have, =

sinsin

i

rand also =c

v

cv

i

r= sin

sin

v c ri

=

.

sinsin

45. As the angle between vand Eis neither zeronor , a constant force ( ) qE will act on theelectron. The motion of the electron, thereforewill be along a parabola.

46. We knowr EV

R= 1

hence, R= 39. , E= 2 0. V,r= 01. hence, V= 195. V

47. Heat required, Q= 1000 1 100 20( )

= 1000 80 calHeat produced in time tis, H VIt =


7/21/2019 bihar '13

18/30

= 220 4 tJ

= 220 4

418t

.cal

= = 220 4418

1000 80t

.

t=

1000 80418 220 4.

= 63. min

48. (d) Pair production is just oppsite to massannihilation. When suddenly -ray energydisappears to form a pair of a particle and ananti-particle, the process is called pairproduction.

49.(b) Resolving power 1

and 1v

R P v.

( . ) ( . )R P R P2 1

8020

= kVkV

= 2 1( . )R P50. (c) Electric field between the oppositely

charged plates of a capacitor is twice that dueto one plate Hence, when one plate isremoved, the electric force reduces to half ofits earlier value.

Chemistry

1. CH C

CH

CH

CH

OH

CH3

3

3

3

H

+

CH C

CH

CH

C H

O H

CH3

3

3 2

3

H O2

CH C

CH

CH

C H CH3

3

3

3

2 carbocation

shift

1,2 m

ethyl

CH C

CH

C H

CH

CH3

3

3

3

3 carbocation

Br

CH C

CH

Br

C H

CH

CH3

3

3

3

2. A-hydroxy carbonyl compound is formed bycondensation of carbonyl compound with atleast one hydrogen atom at -carbon.

3. Positive inductive effect (+Ieffect) is arisesdue to electron releasing group ( )y. Itdevelops negative charge on chain and exertsa positive inductive effect.

C +

y

Therefore, +Ieffect tends to decrease positivecharge and tends to increase stability.

4. C H OA

C H OB

4 6 4 3 6 2

From above equation, it is clear that CO2 islost due to heating. Thus, A is a dibasic acidwith two COOH groups on same carbonatom (gemposition). Thus, A is

CH COCOOH

COOHCH CH C3

'A'methyl malonic acid

3 2H

OOH 'B'propanoic acid

Soda lime

3 3'C'

ethane

CH CH

For 1 mole of C again,CH CH3 3(mol wt= 30)

Q30 g of Coccupies volume=

2242.

1 g of Cwith occupy volume =22.430

~0.75 L

5. When an extra electron is added in nitrogenatom, added electron will be screened by five


7/21/2019 bihar '13

19/30

electrons in second orbit ( )2 22 3s p and twoelectrons in first orbit ( )1 2s .

Now screening constant, = 5 0 35. in nthorbit + 2 0.85 in ( )n 1th orbit= +175 170. . = 345.Effective nuclear charge = 7 3.45 = 3.55

6. MS2 2 D

100 40.06

M+ 64 64

10064M+

=40.0664

or 40.06 ( )M+ = 64 100 64

or M+ =64 640040.06

or M+ 64 160

or M 160 64

or M ~ 96

7. Formal charge, F v s

u= 2

Where, v=valency electronss=shared electronsu=unshared electrons

H N C : 22sharedelectrons 6unsharedelectro

ns

unshared electrons

H N C

v 1 5 4s 2 8 6u 0 0 2F 0 1 1

8. R= 0.0821 L atm mol K1 1

= 8.314 10 ergs mol K7 1 1

= 8.314 J mol K1 1

= 0002. kcal mol K1 1

1L atm =0.0821

molR

K

1erg =8.314 10

mol7R

K

1 J =8.314molR K

1 kcal =0.002

molR

K

Thus, II < III < I < IV

9.

10. 2Cu + H O + SO + O2 3 2

Cu (OH) SO2 2 42Cu H O + CO O2 2 2 2+ +

Cu (OH) CO2 2 3

11. Mischmetal is an alloy of lanthanide metal(95%) and iron (about 5%) with traces ofsulphur, carbon, calcium and aluminium. It isused in the production of bullets, shells andlighter flint.

12. [Fe(H O) NO]2 52+

This is a typical case of complex formed byelectron exchange. NO changes to NO+ byloss of electron and this electron is gained by

Fe2+which changes to Fe+ NO NO ++ eFe F2+ ++ e e

Thus, oxidation state of iron = + 1

Three unpaired electrons + 1oxidation state isconirmed by magnetic moment of iron= +3 3 2( )

= 15 BM. and also by diamagnetic characterof NO (which is only possible when it has nounpaired electron).

13. 3BCl + 3NH Cl B N H Cl3 4C H Cl

140 C3 3 3 3

6 5

NaBH

3 3 6 borazine orinorganic benzene

4 B N H


2+ 6Fe (z = 26) = Ar 3d

2+ 4Cr (z = 24) = Ar 3d

2+ 6Fe =Ar 4s 3d

+ 7Fe = Ar 4s 3d

(n-1) (n)

e e ectronis screened

7/21/2019 bihar '13

20/30

14. Let atomicity of sulphur isn, then it exists asSn.

Molar mass, m= 32n

Now from, T w Km wff= 1000

0.0101000 2.56 0.1

100=

m

or m=

=1000 2.56 0.1

0.010 100256

or 32 256n=

or, n= =25632

8

15. By set I, half-life is 2 min. In set-II, number ofmoles have been doubled, thus half-life isalso doubled,i e. ., now it is 4 min. Thus,

8 mol change to 4 mol (half) in = 4 minand 4 mol change to 2 mol (half) in = 2 min.Thus, total time = + =4 2 6 min.

16. NH OH + H NH + H O4+

4+

2

K= = [NH ] [H O][NH OH] [H ]

1.8 104+

2

4+

9

Again,NH + H O NH OH NH OH3 2 4 4

+ +

=

K[NH ] [OH ]

[NH OH]4+

4

Now = KK

[NH ] [OH ][NH OH]

[NH OH] [H ][NH ] [H O]

4+

4

4 +

4+

2

= [OH ] [H ]+ (QH O2 is in excess)

= = Kw 1 1014

= K K 1 10 14

= 1.8 10 109 14= 1.8 10 5

17. ph of 0.01 M CH COOH3

pH12

= [ ]pK Ca log

= ( . . )12

474 0 01log

= + =( . ) .12

474 2 337

When 0.01 mol CH COONa3 is added to it, it isnow a buffer and [ ][CH3COONa]=0.01 M.Now from

pH[CH COO]

[CH COOH]3

3= +pKa log

= +. ..474 0 010 01log = 474.

Change in pH 4.74 3.37 1.37= =

18. QSalts NH , NH , NH )4 4 4A B C are of weak acidand weak base.

pH 7= +p pK Ka a

2 2Thus, greater the value of pKaof HA, greaterthe pH.

pK (A , B , C ) | A < B < Cb

4 5 6

pKa A B C C B A(H , H , H ) | H8 < H9 < H10Thus, order of pH va;ies is

(NH < NH < NH )4 4 4C B A .

19. p=0.0072 atm

= 0.0072 76 cm of Hg

= 0.0072 76 13.6 cm of mercury column

Also, p h= 1cm of water column

h = 1 0 0072 76 136. . cm

or h= 7 4. cm

20. QHand S remain constant in the giventemperature range.

S G HT

=

=

66.9 + 41.8

300

= 0.08367 kJ K mol1 1

G H T S330 =

= 41.8 330 0.08367 = 69.4 kJ mol 1

21. From Kirchhoff's equation H2 11000 300( ) ( )K H K=

+ Cp ( )1000 300

Here, H21(1000 K) 123.77 kJ mol=

H1(300 K) ?=

C C +P P P P2 (NH ) [C (N ), 3C (H )]3 2 2=


7/21/2019 bihar '13

21/30

= 6 R

= 6 8.314 10 kJ3

=123.77 (300 K)1H 6 8.314 10 7003

or H1(300 K) 88.85 kJ= For two moles of NH3

H Hf(NH )(300 K)23

1=

= 88.852

= 44.42 kJ mol 1

22.

Electrode General Name(A) Calomel Reference(B) Glass Memberane(C) Hydrogen Gas

(D) Quinhydrone Redox

23. E Ecell cell

2

20.0591

2log

[Zn ][Cu ]

= = +

+

= +

+1.10.0591

2log

[Zn ][Cu ]

2

2

Ecell

2

21.1 if[Zn ][Cu ]

1< >+

+

24. 2H 2 H2+ + e

Al 3 Al3+ + ew

w

E

E

(H )(Al)

(H )(Al)

19

2 2= =

w(H ) 4.519

0.5 g14

mol H2 2= = =

= =22.44

5.6 L H2at STP

25.

26. + H Br Br2 hv

(ii)1. D O

(i)Mg/ether

2 D

27. Rate of oxidation depends upon sterichinderance. Greater the steric hinderance theslower is the oxidation. Thus, the correct orderis

> >CH OH

CH OH

CH CHOH

CH CHOH

2

2

(I)3

3

(II)

(CH ) COH

(CH ) COH

3 2

3 2

(III)

28.

29. A gives iodoform test thus A has

C

O

CH3group. C eliminates CO2on heating hence,C has two COOHgroups at same (gem)position.

Since, only (a) hasC

O

CH3group, therefore,

compound A is CH C

O

CH C

O

OC H3 2 2 5

.

CH C

O

CH C

O

OC H CH I3 2 2 5NaOH/I

3

A yellow p

2

pt

+

NaOC

O

CH C

O

ONa2

B

+H

CH C

O

OH HOC

O

CH C

O

OH3 2

C

30. (I) Methyl ketones (CH C

O

)3

R react rapidly withhalogens, (Cl , Br , I )2 2 2 in presence of alkali toform haloform.

CH C

O

CH 3I 4NaOH3 3 2

+ +

CH C

O

ONa3

+ + +CHI 3NaI 3H O3 2


CH CH2 3

ethylbicyclo [2, 2, 1] heptane

OH

Phenol

NH2

Aniline(Primany amine)

NH3

ZnCl2

7/21/2019 bihar '13

22/30

CH C

O

ONa H CH C

O

OH3Na

3

+

+

+

(II) Stronger oxidising agents oxidise ketones tocarboxylic acids.

CH C

O

CH3 3K2Cr2O7 + H2SO4

CH C

O

H HC

O

OH3

+

(III) Tollens reagent (ammonical silver nitratesolution), being weak oxidising agent can notreduce acetone into acetic acid.

CH C

O

CH [Ag(NH ) ]3 3 3 2+ + No reaction

31. Benzyl carbocation is more stable then alkyl

(CH CH ).3 2

CH O3 and CH ,3 bothstabilise benzyl carbocation and among themCH O3 is more stable then CH3. Thus,correct order of stabilities will be

IV

7/21/2019 bihar '13

23/30

40. In Goldschmidts alumino thermite process, isused when a high temperature is needed forcarbon to reduce an oxide. In this process alarge amount of energy (1675 kJ mol 1 ) isliberated on oxidation toAl O2 3.

3Mn O 8Al 9Mn 4Al O3 4 2 3+ + B O 2Al 2B Al O2 3 2 3+ + Cr O 2Al 2Cr Al O2 3 2 3+ +

41. In Nelsons cell, H2gas is liberated at cathodewheres Cl2 gas is liberated at anode, onelectrolysis of solution of NaCl.

NaCl Na Cl + +

H O H OH2 + +

at cathodeH e H+ +

H H H2+

at anode

Cl Cl e 1 +

Cl Cl Cl2+

42. SnCl 2NaOH Sn(OH)2 2white ppt

+ + 2NaCl

Sn(OH) 2NaOH Na SnO2 2 2sodium stannite

+

+ 2H O243. N ( ) 3H O( )3 2 + aq l NH ( ) 3OH ( )3g aq+

N3 accepts proton, hence, it is strong

Bronsted Lowry base and reacts with water toproduce NH3and OH

ions.

44. (wave number) =

R Z

n nH

2

12

22

1 1

1(He , Z 2) (2)1

n

1n

H2

12

22

+ = =

R

23 2

12

224 4

1 1(Be ,Z R

n nH

+ = = =

) ( )

2

1

2

242

164

4= = =( )( )

2 14=2

14= x cm

45.

(Oxidation number two O atoms taken)On balancing of oxidation number3H O 2MnO 2MnO 6H O2 2 2 4 2+ +

Thus, H O : MnO 3 : 22 2 2=

46. KCl AsNO3MV M V 1 1 2 2

=

M1

1 20

25=

= 0 8. M i x= + = + =( )1 1 1 2

T K if f= molality = = 0.8 2 2 3.2

47. According to Lux- Flood concept, acid isdefined as a substance which can acceptoxide and base as a substance which candonate oxide.

CaO CO Ca CObase acid

22

32+ +

48. Negatively charged colloidal sol is formedwhen AgNO3 is completely precipitated as

AgI and extra KI is absorbed on AgI.Ag I AgI+ +

AgI I [AgI]I+

Thus, [Ag ] [I ]+

Documents

bihar '13