Download Assignment (Summer Holidays-2016-17)

HOLIDAY ASSIGNMENT
CLASS-XII
SUBJECT- BIOLOGY
1.Q:
2.Q:
3.Q:
4.Q:
Why is reproduction essential for organism
Distinguish between asexual and sexual reproduction
Why is vegetative reproduction considered as a type of asexual reproduction
What are vegetative propagules? Name any four of them along with an
example for each.
5.Q: State the difference between meiocyte and gamete wih respect to chromosome number
6.Q: What is fission? What is basic difference between fission in amoeba and
paramecium?
7.Q: Draw sketches of zoospores and conidium. Mention two dissimilarities between them and
atleast one feature common to both structure.
8.Q: What is parthenogenesis? Explain giving example.
9.Q: Which is the first diploid single cell which begins life?
10.Q: Amoeba is immortal. Explain.
11.Q: Which is the most critical event in sexual reproduction?
12.Q: Differentiate between internal and external fertilization.
13.Q: What is nucellus? Describe its function.
14.Q: What is the function of germpore? How pollination takes place? Discuss various agents
of pollination.
15.Q: What is polyembryony? Give two examples.
16.Q: Draw a diagram of male gametophyte of angiosperm. Label its parts.
17.Q: Name the component cell of egg apparatus in embryosac.
18.Q: What is triple fusion? Where and how does it take place?
19.Q: Differentiate between (a)geitonogamy and xenogamy
(b)Hypocotyls and epicotyls
(c)Coleoptiles and coleorhizae
20.Q: Draw a neat labeled diagram of mature angiospermic embryosac. Mention
the role of synergids.
21.Q: What is meant by monosporic development of female gametophyte?
22.Q: Write short note on apomixis.
23.Q: What is meant by emasculation? When and why does a plant breeder employ
this technique?
24.Q: Differentiate between microsporogenesis and megasporogenesis
25.Q: What is self incompatibility? Discuss in detail.
Assignment (Summer Holidays-2016-17)
Class: XII
Subject: Physics
26.Q: 1. What happens to the energy stored in a capacitor if after
disconnecting the battery, the plates of a charged capacitor are moved
farther?
27.Q: 2. What happens to the energy stored in a capacitor if, the plates of a
charged capacitor are moved farther, the battery remaining connected?
28.Q: 3. When a capacitor is charged by a battery, does the energy stored
by a capacitor remain same as energy supplied by the battery?
29.Q: 4. Two charges 5 nC and -2 nC are placed at points (5 cm, 0, 0) and
(23 cm, 0,0)in a region of space where there is no other external field.
Calculate the electrostatic potential energy of this charge system?
30.Q: 5. A regular hexagon of side 0.10 m has a charge 5 µ c at each of its
vertices. Calculate the potential at the centre of the hexagon.
31.Q: 6. Two charge conducting spheres of radii a and b are connected to
each other by a conducting wire. What is the ratio of (i) charges on the
spheres and (ii) electric fields at the surfaces of the two spheres.
32.Q: 7. A spherical conductor of radius 12cm has a charge 1.6 x 10-7 C
distributed uniformly on its surface. What is the electric field: (i) inside the
sphere (ii) just outside the sphere.
33.Q: 8. Three capacitors each f capacitance 9 pF are connected in series:
34.Q: a) What is the total capacitance of the combination?
35.Q: b) Determine the charge on each capacitor if the combination is
connected to 120 V supply.
36.Q: 9. Three capacitors of capacitances 2 pF, 3 pF and 4 pF are connected
in parallel
37.Q: a) What is the total capacitance of the combination?
38.Q: b) Determine the charge on each capacitor if the combination is
connected to a 100 V supply?
39.Q: 10. Net capacitance of three identical capacitors in series is 1 µF. What
will be their net capacitance if connected in parallel?
40.Q: Find the ratio of energy stored in the two configurations if they are
both connected to the same source.
41.Q: 11. Using the mathematical expression for the conductivity of a
material, explain how it varies with temperature for (i) semiconductor (ii)
good conductors.
42.Q: 12. A cylindrical metallic wire is stretched to increase its length by
10%. Calculate the percentage increase in its resistance.
43.Q: 13. Two heaters are marked 200 V, 300 W and 200 V, 600 W. If the
heaters are connected in series and the combination connected to a 200
V dc supply, which heater will produce more heat?
44.Q: 14. Let an electron circulates around the nucleus in the path of radius
5.1 X 10 -11 m at a frequency of 6.8 X 10 15 rev/s. Calculate the magnetic
induction at the centre of the orbit. What is the equivalent dipole
moment?
45.Q:
46.Q: 15.An electron is moving at 10 6 m s -1 in a direction parallel to a current
of 5 A flowing through an infinitely long straight wire separated by a
perpendicular distance of 10 cm in air. Calculate the magnitude of force
experienced by the electron.
47.Q:
48.Q: 16. A solenoid is 2 m long and 3 cm in diameter. It has 5 layers of
winding of 1000 turns each and carries a current of 5 A. What is the
magnetic field at its centre?
49.Q:
50.Q: 17. A battery of e.m.f. 3 volt and internal resistance of r is connected in
series with a resistor of 55 Ω through an ammeter of resistance 1 Ω. The
ammeter reads 50 m A. Draw the circuit diagram and calculate the value
of r.
51.Q:
52.Q: 18. A 20 V battery is charged by a 210 V d.c. supply. What is the
current supplied by the battery charger if the resistance in the charging
circuit is 40 Ω and the internal resistance of the battery is negligible?
53.Q:
54.Q: 19. A 50 MW electric power station sends power to a load through
cables. Power is sent at (i) 50000 V and (ii) 500 V. Calculate the power
loss in each case.
55.Q:
56.Q: 20.To produce 10 3 joules in 10 seconds, how much voltage should be
applied to 100 ohm resistance?
57.Q:
58.Q: 21. A letter A consists of a uniform wire of resistance of one ohm per
cm. The sides of the letter are 20 cm long and cross-piece in middle is 10
cm long, while the apex angle is 60 0. Find the resistance of the letter
between two ends of the legs.
59.Q:
60.Q: 22.Three resistors 2 Ω, 3Ω and 4 Ω are connected in series. This
combination is connected to a source of emf 10 V. What is the potential
drop across each resistor?
61.Q: 23. A free proton and free electron are placed in a uniform field. Which
of the two will experience greater force and greater acceleration?
62.Q:
63.Q: 24. An electrostatic line of force cannot have sudden makes and
breaks. Why?
64.Q:
65.Q: 25.Two charges of + 10µC and +40 µC respectively are placed 12 cm
apart. Find the position of the point, where electric field is zero.
66.Q:
ASS IGNMENT
ORGANIC CHEMISTRY
CLASS XII (2016-17)
1 .An organic compound (A) (molecular formula C 8H16O2) was hydrolysed with dilute
sulphuric acid to give a carboxylic acid(B) and an alcohol (C) Oxidation of (C) with
chromic acid produced (B). (C) on dehydration gives but-1-ene.Write equations for
the reactions involved.
2. Arrange the following compounds increasing order of their property as indicated:
(a) Acetaldehyde Acetone,Di-tert-buty1 ketone, Methyl tert-buty1 ketone
(reactivity towardsHCN)
(b) CH3CH2CH(Br) COOH,CH3CH(Br)CH2COOH,
(CH3)2CHCOOH,CH3CH2CH2COOH(acid strength)
(c) Benzoic acid,4-Nitrobenzoic acid,4-Dintrobenzonic acids,4-Methoxy-benzoic
acids(acid strength)
3.Give plausible explanation for the each of the following:
(i)
(ii)
(iii)
Cyclohexanone forms cyanohydrins in good yield but2,2,6-trimethycyclohexanone does not.
Three are two-N H2 groups in semicarbazide. However only one is involved
in the formation of semicarbazones
During the preparation of ester from a carboxylic acid and an alcohol in
the presence of an acid catalyst, the water or the ester should be removed
as soon as it is formed.
4.Account for the following:
(I)
(II)
(III)
Chloroacetic acid has higher pKa value than acetic acid
Electrophilic substitutions benzoic acids take place at meta position
Carboxylic acids have higher boiling points than alcohols of comparable
molecular masses.
5.Give explanation for the following observation:
Towards nucleophillic reagents, aldehydes are more reactive than ketones.
Accounts for the following:
(i)
(ii)
Chloroacetic acid is stronger acid than acetic acids.
Aldehydes are more than volatile than the corresponding alcohols
6. Give reasons for the following :
(a) Carboxylic acids do not give characteristic reactions of carbonyl group.
(b) Treatment of benzaldehyde with HCN gives a mixture of two isomer which
cannot be separated even by careful fractional distillation.
(c) Sodium bisulphite is used for the purification of aldehydes and ketones.
7. An organic compounds (A) which has characteristics odour , on treatment with
NaOH forms two compounds (B) and (c) compounds (B) has the molecular formula
C7H8O which on oxidation with CrO3 gives back compounds (A) ,Compounds (C) is
the sodium salt of acids (C) when heated with soda lime yield an aromatic
hydrocarbon (D). Deduce the structures of (A),(B),(C) and (D).
8.(a) How will you convert:
(i)
Benzoyl chloride to benzaldehyde
(ii)
Propanone to propane -2-ol
(iii)
Benzoic acids to m-nitrobenzoic acid
(b)Write the names and structure of the products formed in the followings reactions:
(i)
Reactions of semicarbazide (NH2CONHNH2) with formaldehyde .
(ii)
Oxidation of ethylbenzene with alkaline KMnO 4
9.(a)Write the complete reaction for each of the following conversions starting the
conditions necessary:
(i)
Toluene to benzaldehyde
(ii)
An aldehyde to an acetal
(iii)
Benzoic acids to 3-bromobenzoic
(b) How will you account for the following:
Chloroacetic acids is stronger acids than acetic acids.
10. State chemical tests to distinguish between the following pairs of compounds:
(i)
Propanal and Propanone
(ii)
Phenol and benzoic acids.
(b) How will you bring about the following conservation:
(i) Propanone to Propene
(ii) Benzaldehyde to benzopheno
(iii)Ethanol to 3-hydroxybutanal.
11. State reasons for the following :
(i)
Monochloroethanoic acids has a higher pKa value than dichloroethanoic
(ii)
Ethanoic acids is a weaker acid than benzoic acids.
12.How would you accounts for the following :
(i)
Aldehydes are more reactive than ketones towards nucleophiles.
(ii)
The boiling points of aldehydes and ketones are lower than of the
corresponding acids.
(iii)
The aldehydes and ketones undergo a number of addition reactions.
(b)Give chemical tests to distinguish between:
(i)
Acetaldehyde and benzaldehyde
(ii)
Propanone and propanol.
13. (i)Describe the preparation of the acetic acid from acetylene.
(ii) How can the following be obtained from acetic acid:
(a) Acetone?
(b) Acetaldehyde ?
14 (i) In what way can acetic acid be distinguished from acetone?
(ii) Why do carboxylic acids not give the characteristics reactions of a carbonyl
group ?
15. Write the chemical tests to distinguish between the following pairs of
compounds:
(i) Acetophenone and Benzophenone
(ii) Ethanal and Propanal.
16. Does the presence of two chiral carbon atoms always make the molecule
optically active? Explain giving an example.
17. How are enantiomers different from diastereoomers? Give one example of each?
18(i)Why are haloalkanes more reactive towards nuclepo substitution reactions
than haloarenes ?
(ii) Which one of the following two substance undergoes S N1 reaction faster and
why?
19. What happen when bromine react with CH 3-C=CH? How would you justify this
reaction?
20. Explain why alkyl halidas undergo hydrolysis more easily as compared to aryl
halidas?
21. Why are haloarenes more stable than haloalkanes and undergo electrophillic
substitutions at ortho and para positions.
22. How will you convert:
(a) Chlorobenzene to phenol
(b) Bromomethane to ethanoic acid
© Chlorobenzene to anline?
23. How will you prepare chloroform from ethanol ? Give equations.
24.How can you bring about following conversions ?
(i) Ethyne into propyne
(ii) 2-Bromopropane into 1-bromopropane
(iii) Ethene into propanoic acid.
25.Give reasons
(i) Cholorform is a chlorine compound but it does not give any precipitate with silver
nitrate solution.
(ii) Boling point of alkyl bromide is higher than alkyl chloride
(iii) Alkyl halidas are better solvent than aryl halides.
(iv)Haloalkanes used as solvent in industry are chloro compounds rather than bromo
compounds.
26. A cholro compounds (A) on reduction with Zn-Cu alcohol gives the hydrocarbon
(B) with five carbon atoms. When A is dissolved in ether and treated with sodium
2,2,5,5-tetrmethylhexane is formed. Write the structure of A and B.
27.(i)What effect should the following resonance of vinyl chloride have on its dipole
moment.
CH2CH-Cl↔-CH2-CH=Cl+
(ii) Iodoform obtained by the reaction acetone with hypoiodite but not with iodide
ion.
(iii) Vinyl chloride is hydrolysed more slowly than ethyl chloride.
(iv) optically active 2-idobutane on treatment with Nal in acetone gives a product
which does not show optical activity.
28.The treatment of alkyl chloride with aqueous KOH leads to the formation of
alcohols but in the presence of alcoholic KOH alkenes are major products. Explain.
29.Primary alkyl halide C4H9Br (a) is reacted with alcoholic KOH to give compound
(b) is reacted with HBr to give (c) which is an isomer of (a) When (a) is reacted with
sodium metal, it gaves compounds (d) C8H18 which is different compounds formed
when n-dutyl bromide.
30. Give at least one Characteristic test which distinguish between bromobenzene
and benzyl bromide.
31.Alkyl halides give cyanides with KCN but isocyanides with AgCN as the products.
Explain.
32. Alcohols are comparatively more soluble in water than hydrocarbon of
comparable molecular masses. Explain this fact.
33. While separating a mixture of ortho and Para
nitrophenols by steam distillation, name the isomer which will be steam volatile.
Give reason.
34.
How will you distinguish between following:I)
tert-Butyl chloride and Butyl chloride
ii) Methanol and Ethanol
35. Write the mechanism of hydration of ethane to yield ethanol.
36. Write structure of the compounds whose IUPAC names are as follow: 2, 3-Diethyiphenol
 2-Ethoxy-3-methy1pentane
 3-Cyclohexy1pentan-3-o1
37. Explain how does the –OH group attached to a carbon of benzene ring
activate it towards electrophillie substitution?
38. Give equation of the following reaction:
I)
Oxidation of propan-1-ol with alkaline KMnO4 solution.
II)
Bromine in CS2 with phenol.
III)
Dilute HNO3 with phenol.
39 Explain the following with an example:I)
Kolbe’s reaction
ii) Reimer-Tiemann reaction
iii) Williamson ether
synthesis
40 a) Show the mechanism of acylation of ethanamine and write the IUPAC name
of the product formed .
b) Write a chemical reaction in which the iodide ion replaces the diazonium
group in a diazonium salt.
41 An aromatic compound (A) on treatment with ammonia followed by heating
forms compound (B) , Which on heating with Br 2 and KOH forms a compound(c)
Having molecular formula C
reactions involved
6
H7 N. Give the structure of A, B and C and write the
42 Account for the following observation:
a) pKb value for aniline is more than that for methylamine
b) Methylamine in water reacts with ferric chloride to give a precipitate of ferric
Hydroxide
c) Aniline does not undergo Friedel-Crafts reaction.
43 a) Predict giving reasons the order of basicity of the following compounds in (i)
gaseous phase and (ii) in aqueous solution (CH 3)3N, (CH3)2NH,CH3NH2,NH3
b) Give the chemical tests to distinguish between the following pairs of compounds:
(i)Methylamine and Dimethylamine
(ii)Aniline and N-methyaniline
44 In the following cases rearrange the compound as directed :
(i) In a decreasing order of basic strength:
toludine
Anline, p-nitroaniline and p-
(ii) In an increasing order of pKb values:
C6H5NH2
C 2H5NH2,C6H5NHCH3,(C2H5)2 and
45 Give plausible explanation for each of the following.
(i) The presence of a base is needed in the ammonolysis of alkyl halides.
(ii) Aromatic primary amines cannot be prepared by Gabriel phthalamide syntheses.
Maths Assignment(XII)
1 If A=
[
2 −1 1
−1 2 −1
1 −1 2
]
and B=
[
3 1 −1
1 3 1
−1 1 3
]
,find AB and use this result to
solve
2x-y-z=-1, -x+2y-z=4, x-y+2z=-3.
2 A=
[
1 −2 1
−2 3 1
1
1 5
]
−1
−1
verify (adj A ) = (adj A ¿ ¿ .
n
n n
3 If matrices A,B commute by induction prove ( AB) = A B
|
4 Prove
5 A=
[
|
b 2+ c2
ab
ac
2
2
ab
c +a
bc
2
ca
cb
a + b2
2 −1 1
−1 2 −1
1 −1 2
]
=4abc
−1
,find A
by elementary column operations.
[ ]
2 2 0
6 Find a matrix A such that | A| =2 and adj A= 2 5 1
0 1 1
|
7 If a,b,c in A.P,without expanding prove
8 If A=
[
2 −1 1
−1 2 −1
1 −1 2
]
|
2 y +4 5 y +7 8 y +a
3 y +5 6 y+ 8 9 y +b
4 y+ 6 7 y + 9 10 y +c
is zero.
3
2
−1
verify A -6 A +9A-4I=0.Hence find A .
5
9 Find principal values of cos(cos10),sin(sin5),tan(tan( 6 π))
−1
10 Simplify sin
(sinx+ cosx)
√2
−π π
,
4 4 );
,xє(
cosx
tan( 1−sinx ) ; x є (
−π π
,
2 2 )
−1 1
−1 1
11 Prove cos(2 tan 7 )=sin(4 tan 3 )
12 Solve for x;
tan −1
1
1
tan−1
4 +2
5
tan −1
+
1
6
+
tan −1
1
x =
π
4
−1 3
−1
13 Solve for x:cos( tan x)=sin( cot 4 )
1
14 A function F is defined by f(x)=
ex
1
e x +1
,Discuss the continuity at x=0.
15 Discuss the continuity of the function defined by F(x)=
2
{
x
|x|+3 x 2 ifx ≠ 0
1 if x=1
2
16 A function F is defined by F(x)=2 x - x
1<x ≤2
= 5x – 4
x> 2
Discuss the continuity and differentiability at x=2.
3x
e +logx
17 Y= sin √ x
18 Y=log(x+2+
19 If y=
dy
, find dx
√ x2 + 4 x+1 ; find
x √ a2−x 2
2
20 If y=sin(2tan
21 If y=cos
(x>0).
√
dy
dx .
x
dy
2
+ a sin a ; Prove dx =
(1−x)
(1+ x) );find
√ cos 3 x /cos 3 x , Prove
x+ y
√ a2−x 2 .
dy
dx .
dy
dx =
√
3
cosxcos 3 x .
dy
y
x
22 If x + y = ( ¿ ¿ x+ y ,find dx .
2
2
23 If F(x) = sinѲ, y= cospѲ, prove (1- x ) y 2 - x y 1 + p y=0.
2
24 If 2a+3b+6c=0, by Rolle’s theorem show that the equation a x +bx+c=0
has atleast one real root between 0 and 1.
25 Verify Lagrange’s mean value theorem for the function
F(X)= |x +2| on [ −3,4 ] .