summer break assignments class 12

(CHEMISTRY)
If three elements X,Y and O crystallize in a cubic solid lattice with X atoms at the corners, Y
Atoms at cube center and O atoms at edges then what is the formula of the solid?
1. Which Type of Point Defect occurs in Zinc Blende?
2. A metallic element crystallized into ABABAB … . Any packing of spheres leaves out voids in the lattice. What % by volume of this lattice
is empty space?
3. In the closest packing of atoms A of Radius R. What is the radius of atom B that can be fitted into the octahedral voids?
4. A metal oxide has the Empirical Formula
M0.9601.00. Calculate the % of M2+ and M3+ions in this crystal?
-3
-3
5. An Element M crystallizes in BCC structure. If the edge length of the cell is 1.49 x 10 m and density is 19.3 g cm , calculate the
atomic mass of this element.
6. An Element X with an atomic mass of 60 g/mol has density 6.23 g cm-3. If the edge length of its cubic unit cell is 400 pm, identify the
type of unit cell and calculate the radius of the atom.
7. Copper crystallizes with FCC unit cell. If radius of copper atom R=127.8 pm, calculate the density of copper metal.
8. The Density of TlCl lattice is 9 g cm
-3
and edge length of the solid is 3.85 x 10
-8
cm. What is the unit cell geometry?
9. CsBr crystallizes in the cubic system. Its unit cell has Cs+ ions at the Body Centre and Br- ions at each corner. Its density is 4.44 g cm-3.
Determine the (a) edge length of unit cell and (b) fraction of volume occupied per unit cell.
10. Chromium metal crystallizes with a BCC lattice. The edge length of unit cell is 287 pm. Calculate its atomic radius and density of the
chromium in CGS system.
11. Define the followingi. Unit Cell ii. Co-Ordination No iii. Schottky Defect
iv. Frenkel defect
v. F-Centres
13.Why is glycol and water mixture used in car radiators in cold countries?
14-Two liquids A &B on mixing produce a warm solution. Which type of deviation from
Raoult’s Law is expressed?
15-Of 0.1 molal solution of BaCl2and sodium chloride respectively, which one will have
a higher boiling point?
16-Define osmotic pressure and reverse osmosis.
17-Define ideal solution and non ideal solution with examples.
18. What is the value of van’t Hoff factor for K4[Fe(CN)6], if it is 100% dissociated?
19-Why does a solution of cyclohexane and ethanol show positive deviation from Raoult’s law?
20. How does sprinkling of salt help in clearing the snow covered roads in hilly areas? Explain
the phenomenon involved in the process.
21. State Henry’s law and mention some important applications.
22. Assuming complete ionization, calculate the expected freezing point of solution prepared
by dissolving 6.00g of Glauber’s salt, Na2SO4·10H2O in 0.1kg of H2O.
(Kf for H2O=1.86 K kg mol-1).
23. An aqueous solution of 3.12 g of BaCl2 into 250 g of water is found to boil at100.0832°C. Calculate the degree of dissociation of
BaCl2 .
Kb(H2O) = 0.52K/m.
24. Vapour pressure of CHCl3 and CH2Cl2 at 298K are 200 mm Hg and 415mm Hg respectively.
(i) Calculate the vapour pressure of the solution by mixing 25.5 g of CHCl3 &40 g of CH2Cl2
at 298K
(ii) Mole fraction of each component in vapour phase.
(Molar mass CHCl3 =118.5 CH2Cl2 = 85)
25. Define the term osmotic pressure. Describe how the molecular mass of a substance can
be determined by the measurement of osmotic pressure?
26. What do you mean by Raoult’s law ? What are the limitations of Raoult’s law ?
27.A solution containing 18 g of non-volatile solute in 200g of water freeges at 272.07 K. calculate the molecular mass of solute
(given Kf = 1.86 K/m)
28.The chairman, Kandla (Gujrat) port due to water scarcity has decided to desalinate sea water
to obtain potable water.
a. As a student of chemistry which method will be suitable to use? (1)
b. Discuss the method. (1)
c. What value have you inculcated in using this method?
Geography
Ch- Fundamentals of human geography
Population composition
Q.1 what do you understand by population composition?
Q.2 what is the significance of age structure?
Q.3 how is sex ratio measured?
Q.4 Describe the rural urban composition of the population.
Q.5 Discuss the factors responsible for imbalance in the sex age found in different parts of the world and occupational structures.
Q.6 what are the three basic areas of human development?
Q.7 Name the four main components of human development?
Q8. How are countries classified on the basis of human development index?
Q9. What do you understand by the term Human development?
Q10. What do equality and sustainability refer to within the concept of human development?
Q.11 Define human development?
Q.12 Give to reasons for low levels of human development in most of the northern states of India?
Q13. Give to reasons for decline child sex ratio in India?
Q.14 discusses the spatial patterns of female literacy in India in 2001 and brings out the reason responsible for it?
Q.15 which factors have caused spatial variation in the level of human development among the 15 major states in India?
Q16. Differentiate b/w barren and wasteland and colourable wasteland?
Q.17 how would you distinguish b/w net sown area and gross cropped area?
Q18. Why IS the strategy of increasing cropping intensity important in country like India?
Q19 How do you measure total cultivable land?
Q20. What is the difference b/w dry land and net land farming?
Q21. What are the different types of environmental problems of land resources in India?
Q.22 what are the important strategies for agricultural development in the post-independence period in India?
History
1-Solving of NCERT questions of lesson 1 and 2 part-1
(History text book).
2-Write the answers of the last years CBSE board questions as given to you in the class work copy.
3-Map work—Show the following on the political outline map of India –
 Important sites of the Harappan civilization.
 Sixteen Mahajanapadas.
4-Source based questions – Read the sources carefully and write the answers of the questions.
5- Learn the questions and answers of lesson 1 and 2
Part 1-(History text book).
Eco
SUBJECT
Micro economics
BREAKS
SUMMER VACATION
12/5/2017 TO 20/6/2017
Macro economics
Learn the theory of of Unit I and II and
Make a list and learn of 40-50 glossary which is given in
practice the numerical.
the and of macro book.
Make the notes of Unit –III and practice
Try to understand unit II of macro that National income
the numerical
and practice numerical
Make a rough copy and make a project of Practice 40-50 numerical of NI and Income and
your …….in about 30-34 pages as per the employment.
topics given in the syllabus.
Listen the video lectures of micro and
Listen the video lectures of macro and make the note
make the note from the same
from the same
Learn to practice the diagrams of the
Learn to practice the diagrams of the micro at least 10micro at least 20-25
15
Solve sample papers of 2016-17 all 3 sets (I,II,III) marking scheme is available on cbse.nic.in
WISH U A VERY HAPPY HOLIDAYS
LIFE WITHOUT GOAL HAS LITTLE VALUE SO SET GOAL AND GO ACCORDINGLY.
Q. NO.
QUESTIONS(1/2 MARKS)
1
If f : R  R be defined as f(x) =
2
If the function f : R  R be given by f(x) = x2 + 2 and g : R  R be given by g(x) =
x
, x  1 , find fog and gof and hence find fog (2) and gof (– 3).
x 1
Ans = (3x2 – 4x + 2)/( x-1)2 , ( x2 +2) / (x2 + 1), 6, 11/10
1
 3  x3 3 , then find f  f(x). Ans = x
Q. NO.
QUESTIONS(4/6 MARKS)
1
Show that the relation R on A , A = { x| x  Z , 0 ≤ x ≤ 12 } ,
R = {(a ,b): |a - b| is multiple of 3.} is an equivalence relation.
Let N be the set of all natural numbers & R be the relation on N × N defined by
{ (a,b) R (c,d) iff a + d = b + c}. Show that R is an equivalence relation.
Show that the relation R in the set A of all polygons as:
R ={(P1, P2), P1& P2 have the same number of sides} is an equivalence relation. What is
the set of all elements in A related to the right triangle T with sides 3,4 & 5 ?
Let n(A) = p and n(B) = q. Find the number of possible relations from A to B. Ans 2pq
Let A=Set of all triangles in a plane and R is defined by R={(T1,T2) : T1,T2  A&T1~T2}
Show that the R is equivalence relation. Consider the right angled ∆s, T1 with size 3,4,5;
T2 with size 5,12,13; T3 with side 6,8,10; Which of the pairs are related?
If R1 and R2 are Equivalence Relation in a set A, Show that 𝑅1 ∩ 𝑅2 is also an equivalence
relation.
Check whether the relation R in R defined by R = { (a, b) : a b3 } is an equivalence
relation.
Ans No
2x  1
Show that the function f: RR defined by f(x) =
.x  R is one- one & onto function.
3
Also find the f -1.
Ans (3x + 1)/2
Consider a function f : R+ [-5, ∞) defined f(x) = 9x2 +6x – 5. Show that f is invertible &
2
3
4
5
6
7
8
9
CHAPTER-1 (RELATIONS AND
FUNCTIONS)
y  6 1
, where R+ = [0,∞).
3
Consider a function f: RR given by f(x) = 4x + 3. Show that f is invertible & f -1: RR
y−3
with f -1(y) = 4 .
Show that f: RR defined by f(x)= x3 + 4 is one-one, onto. Show that f -1(x)=(x– 4)1/3.
𝑥
Show that the function f: R  {x∈R : -1 < x < 1} defined by f(x) =
, x ∈R is one- one
f -1(y) =
10
11
12
1+ |𝑥|
and onto function.
13
14
15
16
17
18
|𝑥−1|
What is the range of the function f(x) = 𝑥−1 , x≠ 1
Ans {-1, 1}
A= N×N & * be a binary operation on A defined by (a , b) × (c , d) = (ac , bd) ∀
(a , b),(c , d)  N×N (i) Find (2,3) * (4,1)
(ii) Find [(2,3)*(4,1)]*(3,5) and (2,3)*[(4,1)* (3,5)] & show they are equal
Show that * is commutative & associative on A.
Given a non-empty set X, let *: P(X) x P(X)  P(X) be defined as
A * B = ( A – B) ∪ (B – A), for all A, B ∈ P(X). Show that empty set ∅ is the identity
element for the operation * and all the elements A of P(X) are invertible with 𝐴−1 = A
Find the number of binary operations on the set {a, b, c}.
Ans 29
A= R×R and * be a binary operation on A defined by (a , b) * (c , d) = (a+c , b+d)
∀ (a , b),(c , d)  A Show that * is commutative & associative on A. Find the identity
element for * on A. Also find inverse of every element (a,b)  A
Ans (0, 0) and (-a, -b)
Let A = R – {-4/3} and B = R – {4/3}. Consider the function f : A  B defined by
f (x) =(4x+3)/(3x+4). Is f one-one and onto? find the inverse of f .
find f-1(0) and x such that f-1(x)=2
Ans (3 – 4x)/ (3x – 4) , -3/4 , 11/10
CHAPTER-2(INVERSE TRIGONOMETRIC FUNCTIONS)
1
 1  sin x  1  sin x  x

  , x   0, 
Prove that cot 1 

 4
 1  sin x  1  sin x  2
2
 1 x  1 x   1
   cos 1 x
Prove that tan 1 

 1 x  1 x  4 2
3
Solve tan 1 2x  tan 1 3x  π / 4
4
Solve tan 1 x  1  tan 1 x  1  tan 1
5
x 1 π
1 x  1
 tan 1

Solve tan
x2
x2 4
Ans x = 1/6
8
31
Ans x = ¼
X =±
Ans
1
√2
6
 cos x   x
  
Prove that tan 1
   , x  , 
 1  sin x  4 2
 2 2
7
Simplify: sin 1 x 1  x  x 1  x 2 ; x  1
8
If tan 1 x  tan 1 y  tan 1 z 
9
Find the value of cos −1 (1+ 𝑥) + cosec −1 (1− 𝑥)



, Prove that xy + yz + zx = 1
2
1−√𝑥
1+√𝑥
√
10
11
12
𝜋
Ans = 2
√
If cos −1 𝑥 + cos −1 𝑦 + cos−1 z = π, prove that x 2 + y 2 + z 2 + 2xyz = 1
x
y
If cos −1 a + cos−1 b = β, prove that
𝑥 2 −1
x2
−
a2
2𝑥
2xy
ab
Solve for x: cos−1 (𝑥 2 +1) + tan−1 (𝑥 2 −1) =
13
Show
14
If tan
y2
cosβ + b2 = 𝑠𝑖𝑛2 𝛽
2𝜋
3
1
3
4−√7
that tan(2 sin−1 4) = 3
−1 𝑥−3+
−1 𝑥+3=↑𝜋 find
𝑥−4
tan
𝑥+4 4
Ans X
x
CH-3 MATRICES
1
2
3
4
5
6
7
8
9
10
0
1 −2
For what value of x, is the matrix A = [−1 0
3 ] a skew-symmetric matrix ?
𝑥 −3 0
1 −1
If matrix A =[
] and 𝐴2 = 𝑘𝐴 ,then write the value of k.
−1 1
Find the value of x + y from the following equation :
𝑥
5
3 −4
7
6
2[
]+[
]=[
]
7 𝑦−3
1 2
15 14
3 4
−1 2 1
If 𝐴𝑇 = [−1 2] and 𝐵 = [
], then find 𝐴𝑇 − 𝐵𝑇 .
1 2 3
0 1
3𝑥 + 𝑦 −𝑦
1 2
Find the value of x , if
[
]=[
]
2𝑦 − 𝑥 3
−5 3
2𝑥 − 𝑦 5
6 5
Find the value of x from following :
[
]=[
]
3
𝑦
3 −2
𝑦 0
1 3
5 6
Find the value of x + y from the following equation : 2 [
]+[
]=[
]
0 𝑥
1 8
1 2
If a matrix has 5 elements , write all possible orders it can have .
2 3
If 𝐴 = [
] , write 𝐴−1 in the term of A
5 −2
0
6 7
0 1 1
2
If A= [−6 0 8]
B = [ 1 0 2]
C= [−2] , then find
7 −8 0
2 2 0
3
AC, BC and (A + B) C. Also verify that (A + B) C = AC + BC.
=±
√17
√2
English
Answer the following in 100-120 words :
Our language is part of our culture and we are proud of it. Describe how regretful the children and the
village elders are for having neglected their native language,French.
2. Give a character sketch of M.Hamel on the basis of your study of the story, ‘The Last Lesson’.
3. ‘Lost Spring’ explains the grinding poverty and traditions that condemn thousands of people to a life of
abject poverty. Do you agree? Why/Why not?
4. The bangle makers of Firozabad make beautiful bangles and make everyone happy but they live and die in
squalor. Elaborate.
5. How is Mukesh more ambitious in life than Saheb? Give a reasoned answer.
Answer the following questions in 30-40 words:
6. What changes came over little Franz after he heard M. Hamel’s announcement?
7. Why has Kamala Das compared her mother to a ‘late winter’s moon’?
8. What is the significance of the parting words of the poet and her smile, in ‘My mother at sixty six’?
9. Why does Stephen Spender say that the pictures and maps in the elementary school classroom are
meaningless?
10. What does the poet want for the children of the slum?
11. You are Karunesh/ Kumud of 148, Raja Nagar, Hyderabad. You are awaiting your class 12th results.
Meanwhile, you would like to do a short-term course on personality development. Write a letter to the
Director, Horizons Institute, Hyderabad, enquiring about the course details.
12. Read two articles from magazine based on your areas of interest and make notes on the same. Also write a
summary of the articles. A copy of the articles should be attached in your notebook.
1.
Biology
1. First unit
2. Second unit – first Chapter All the questions given in NCERT text book & Hots, MLL and VBQ provided.
3. Unit V – all chapters to be prepared along with question answers.