KendriyaVidyalaya Sector-8 R K Puram(2nd Shift)

Summer Vacation Homework

Class – XII

ECONOMICS

1.)A consumer consumes only two goods. Explain equilibrium with the help of utility approach.

2.)Explain consumer’s equilibrium with the help of indifference curve analysis.

3.)A consumer consumes good ‘X’ Explain the effects of fall in the prices of related goods on the demand of ‘X’ . Use diagram showing demand for good X on the X-axis and its price on Y-axis.

4.)Distinguish detween change in demand and change in quantity demanded.

5.)A 3% fall in the price of X leads to a 9% rise in its demand . A 5% rise in the price of Y leads to a 5% fall in its’s demand. Calculate the price elasticity of demand for X and Y . Which one is more elastic?

6.)When price of a good falls from Rs 15 per unit to Rs 12 per unit , it’s demand rises by 25%. Calculate price elasticity of demand.

7.)Price elasticity of demand for a commodity is unity and a household demands Rs 50 units of it when it’s price is Rs2 per unit. At what price will the household demands 45 units of the commodity?

8.)Explain ,in brief, the following kinds of price elasticities of demand, (i) Highly elastic demand, (ii) Unitary elastic demand, (iii) Less elastic demand.

9.)Explain the various factors that affects elasticity of demand.

10) Explain the significance of elasticity of demand.

Physics

  1. Preparation of Innovative exhibit with write ups for Science Exhibition.
  2. Self study of following chapters and follow up exam of 35 marks in month of June. Unit -5 ( EMW), Unit – 6 (ray optics & optical instruments), unit – 8 (Atoms & Nuclei)
  3. Solve following assignment in HW copy

Q1. . An electric dipole is held in a uniform electric field (i) using suitable diagram show that it does not undergo any translatory motion and (ii) drive an expression for the torque acting on it and specify its direction.

Q2. State Gauss’s theorem & apply this theorem to obtain an expression for the electric field intensity at a point due to (i)an infinitely long uniformly charged straight wire (ii) a uniformly charged infinite sheet (iii) a uniformly charged thin spherical shell at an (a) outside point (b) inside point.

Q3. (a)Deduce an expression for the capacitance of a parallel plate capacitor with air as themedium between the plates(b)A dielectric slab of thickness‘t’ is kept in between the plates each of area A of parallel plate capacitor separated by a distance of‘d’. Drive an expression for the capacitance of capacitor for t <d.

Q4. (i) Explain briefly how a capacitor stores energy on charging. Obtain expression for energy stored (ii) A parallel plate capacitor of plate separation’s’ is charged to a p.d. ‘V’. A dielectric slab of thickness d and dielectric constant K is introduced between the plates while the battery remains connected to the plates.

(a) Find the ratio of energy stored in the capacitor after and before the dielectric in

introduced, give physical explanation for this change in stored energy.

(b) What happens to the charge on the capacitor?

(c)How does the electric field between plates change.

Q5. In a Van de Graaff type generator a spherical metal shell is to be a 15 × 106 V electrode. The dielectric strength of the gas surrounding the electrode is 5 × 107Vm–1. What is the minimum radius of the spherical shell required? (You will learn from this exercise why one cannot build an electrostatic generator using a very small shell which requires a small charge to acquire a high potential.) [Ans 30cm]

Q6. A parallel plate capacitor with air as dielectric is connected to a power supply and charged to a potential difference Vo. After disconnecting from power supply, a sheet of insulating material is inserted between the plates completely filling the space between them. How will its (i) charge on the plates (ii) electric field between the plates (iii) potential difference between the plates (iv) capacitance (v) energy stored in the capacitor. Q7. (a) Describe the formula for the equivalent EMF and internal resistance for the parallel combination of two cells with EMF E1 and E2and internal resistances r1 and r2 respectively. (a)What is the corresponding formula for the series combination?

(b) Two cells of EMF 1V, 2V and internal resistances r2 and r1 respectively are connected in (i) series, (ii) parallel. What should be the external resistance in the circuit so that the current through the resistance be the same in the two cases? In which case more heat is nerated in the cells?

Q8. Deduce the condition for balance in a Wheatstone bridge. Using the principle of

Wheatstone bridge, describe the method to determine the specific resistance of a wire in the laboratory. Draw the circuit diagram and write the formula used. Write any two

precautions.

Q9. Describe the principle and construction of potentiometer. Explain how a potentiometer can be used to compare the emfs of two primary cells?

Q 10. Draw Circuit diagram for a meter bridge to determine the unknown resistance of a

resistor. Obtain the balance condition for a meter bridge. Find the shift in the balance

point for a meter bridge when two resistors in its two gaps, are interchanged.

Q 11. Are the paths of e’s straight lines between successive collisions in the (i) absence of electric field (ii) presence of electric field. Establish a relation between drift velocity and current. Hence obtain the relation between current density and drift velocity.

Q12. With the help of a neat and labeled diagram, explain the underlying principle and working of a moving coil galvanometer. What is the function of (i) uniform radial field (ii) Soft iron core?

.

Q13. Using Kirchoff’s laws, calculate the potential difference across the 8 ohm resistor.

[Ans : Current through resistance 8= 0.46A, P. d. = 3.68Volts]

Q14. E2 =1.02V, PQ=1m.When switch S open, null position is obtained at a distance of 51 cm from P. Calculate (i) potential gradient (ii) emf of the cell E1 (iii) when switch S is closed, will null point move towards P or Q. Give reason for your answer.

[Ans: (i) Potential gradient k = 0.02V/cm (ii) emf of the cell E1 = 2V (iii) When switch S is closed, null point is not affected because no current drawn from cell E1 at the null point. ]

Q15. In the potentiometer circuit shown, the balance point is at X. State with reason, where the balance point will be shifted when (i) R is increased; (ii) S is increased, keeping R constant. (ii) Cell P is replaced by another cell whose emf is lower than that of cell Q.

Q16. Two identical plane metallic surfaces A and B are kept parallel to each other in air separated by a distance of 1 cm as shown in figure.

A is given a positive potential of 10V and the outer surface of B is earthed. (i) What is the magnitude and direction of the uniform electric field between Y and Z? (ii) What is the work done in moving a charge of 20 C from X to Y?

Ans : (i) E = 1000 V/m, direction from A to B

(ii) Zero.

Q17. The following data was obtained for the dependence of the magnitude of electric field, with

distance, from a reference point O, within the charge distribution in the shaded region.

Field Point / A / B / C / A’ / B’ / C’
Magnitude
of electric
field / E / E/8 / E/27 / E/2 / E/16 / E/54

(i) Identify the charge distribution and justify your answer.

(ii) If the potential due to this charge distribution, has a value V at the point A, what is its value at the point A’?

Q18. Use Gauss’s law to obtain an expression for the electric field due to an infinitely long straight uniformly charged wire. Electric field in the above figure is directed along + X direction and given by Ex = 5Ax + 2B, where E is in NC-1 and x is in metre, A and B are constants with dimensions

Talking A=10NC-1m-1 and B = 5NC-1 calculate. (i) the electric flux through the cube. (ii) net charge enclosed within the cube.

[Ans(i ) 0.05Nm2/C (ii) 44.25X10-14C ]

Q19. Two point charges of charge values Q and q are placed at distance x and x/2 respectively from a third charge of charge value 4q, all charges being in the same straight line. Calculate the magnitude and nature of charge Q such that the net force experienced by the charge q is

zero. [Ans Q = q/4 , +ive ]

Q20Total capacitance of the combination between A and B in the given figure is 15μF. Calculate the capacitance of capacitor C.

[ Ans. 60 μF]

Q21. On charging a parallel plate capacitor to a potential V, the spacing between the plates is halved, and a dielectric medium of r = 10 is introduced between the plates, without disconnecting the d.c source. Explain using suitable expressions, how the (i) capacitance (ii) electric field (iii) energy density of the capacitor change.

[Ans(i) C1= 20Co (ii) E 1=2Eo (iii) u1 = 40uo]

POLITICAL SCIENCE

  1. Solve your monthly test question paper in your note book.
  2. Chapter for self study is end of Bipolarity.
  3. Answer all these questions in your note book.

THE COLD WAR ERA

  1. What is meant by "Arenas of cold war"?
  2. Why did India not join either of the two camps during the cold war?
  3. Mention military alliances which were set up after the Second World War.
  4. Name any two factors of Non-Aligned Movement (NAM). The first NAM Summit was the culmination of which three factors.
  5. Assess India's role in strengthening the Non-Aligned Movement.
  6. What is the relevance of the Non-Aligned Movement after the end of cold war? Explain.
  7. What is meant by New International Economic Order? Mention any four reforms of the Global Trade System proposed by UNCTAD in 1972.
  8. Write a short note on following:
  1. Limited Test Ban Treaty
  2. Nuclear Non-Proliferation Treaty
  3. Strategic Arms Limitation Talks (I)
  4. Strategic Arms Limitation Talks (II)

CHALLENGES OF NATION BUILDING

  1. Who was the first Indian to be Governor General of India? He founded which party in 1959?
  2. Who was Potty Sriramulu? What was the outcome of his indefinite fast?
  3. Explain the circumstances that compelled the union government to announce the formation of a separate Andhra state in December 1952.
  4. Mention the role of SardarVallabhbhai Patel towards India's integration.
  5. Describe briefly any four problem faced in the process of partition of India.

ERA OF ONE-PARTY DOMINANCE

  1. Analyse the reason for the dominance of Congress party in the first three general elections.
  2. Explain how the General Election of 1952 in India were a landmarks in the history of democracy all over the world.
  3. Write a short note on Communist Victory in Kerala in 1957.
  4. During the early years of Independence, despite the fact that the opposition parties had token representation they played a crucial role in maintaining the democratic character of the system. How?

BUSINESS STUDIES

1Make a project file either on;

Principles of management

Elements of business environment

2make notes on chapter 1 to 4

3learn all chapters 1 to 4

4write atleast 5 multidisciplinary questions and answers from chapter 1 to 4

5write 5 hots and value based questions answers from each chapter done.

ACCOUNTANCY

1 Make a comprehensive project

2 complete exercise of book from chapter 1 to 4

3 make 5 short theory question answer fromeach chapter done

4 revise all chapters till admission of a partner.

Subject:Biology.

  1. Answer all the questions of lesson 1to 4 in H.W copy.
  2. Complete the assigned work in practical file.
  3. Select any suitable application based project and collect information related to it and chalk out its experimentation ect.
  4. Read carefully the following lessons and frame 2,3 5 marks questions.(10 questions of 2 marks,10 of 3 marks and 3 of 5 marks.)

EVOLUTION

ORGANISM AND POPULATION

BIODIVERSITY

ENVIRONMENTAL POLLUTION

5.Paste question paper of monthly test of MAY in C.W copy and answer all the questions.

English Core

Q1. (a) Read at least two short reports in any English newspaper. Cut and paste them on your note-book. On the basis of your reading of these reports, make notes on them in points only, using headings and sub-headings. Use recognizable abbreviations wherever necessary.

(b) Make a summary of these passages in not more than 80 words and also suggest a suitable title.

Q2. You have cleared Medical Entrance Examination. The family is elated at this achievement and they decide to have a get-together for all friends. Draft an informal invitation for the get-together.

Q3. You want to sell car as you are going abroad. Draft a suitable advertisement to be published in a national daily.

Q4. Water is precious and each one of us must stop wastage. Design a poster in not more than 50 words urging people to employ various methods of rain water harvesting in their colonies.

Q5. You lost your bus pass in the school. Write a notice in not more than 50 words giving details of the pass and the probable time of the day you lost it.

Q6. Your school organized a ten day camp in a village during the summer holidays. As the leader of team, write a letter to the editor of a newspaper giving an account of your activities there.

Q7. Stefani of 15-A, C.P. Road, New Delhi desires to be a fashion designer. She writes to the Director of the National Institute of fashion Technology, Bangalore, seeking information about their courses, admission procedure, eligibility criteria, fee structure, placement opportunities etc. Write her letter.

Q8.In spite of the advancement in technology, luxuries and freedom, the new generation is a worried lot. Write an article in about 100 words giving your views on this. You are Kartik/kritika.

Q9. Describe the dramatic entry of the stranger at the Coach and Horses and his strange behaviour.

10. Describe the meeting between Marvel and the Invisible Man.

Computer Science

  1. What will be the output of the following program:

#include <iostream.h

void Secret(char Str[ ])

{for (int L=0;Str[L]!='\0';L++);

for (int C=0;C<L/2;C++)

if (Str[C]=='A' || Str[C]=='E')

Str[C]=Str[L-C-1];

else

{char Temp=Str[C];

Str[C]=Str[L-C-1];

Str[L-C-1]=Temp;

}

}

void main()

{ char Message[ ]="PreboardExam";

Secret(Message);

cout<Message<endl;

}

  1. Find the output of the following program:

# include <iostream.h

# include <conio.h

# include <stdlib.h

void main ()

{

char serial[] = {'A', 'B', 'C', 'D'};

int number[] = { 2, 6, 7, 3};

clrscr();

randomize();

cout < " The winner is : ";

cout < serial [random(3)];

for (int i = 0; i < 4; i++)

cout < number[sizeof(int) + random(2) - 1 ];

getch();

}

Outputs:

(i)The winner is : A2776

(ii)The winner is : D6766

(iii) The winner is : B6767

(iv) The winner is : C3672

  1. Define a class Taxpayer, whose class description is given below:-

Private Members:-

int pan - to store the personal account no.

char name[20] - to store the name

floattaxableinc - to store the total annual taxable income.

float tax - to store the tax that is calculated.

computetax ( )- A function to compute tax from the following rule:-

Total Annual Taxable Income Rate of Taxation

Up to 60000 0%

Greater than 60000, less than = 150000 5%

Above 150000, upto 500000 10%

Above 500000 15%

Public Members :-

inputdata ( ) - A function to enter the data and call the compute tax( ) function.

display( ) - To display the data.

  1. Define a class Library in C++ with with the following specification

`Private Members:

B_code of type integers

Description of type string

No_of_pages of type integer

Price of type integer

A member function calculate( ) to calculate and return the price as

(No_of_pages* Price)

Public Members

(i)A function Enter( ) to allow user to enter values for B_code, Description, No_of_pages & call function calculate( ) to calculate the price of the books.

(ii)A function Disp( ) to allow user to view the content of all the data members.

  1. Define a class Travel in C++ with the following descriptions :

Private Members :

TravelCode of type long

Place of type character array (string)

No_of_travellers of type integer

No_of_buses of type integer

Public Members :

A function NewTravel() which allows user to enter TravelCode, Place and

No_of_travellers. Also, assign the value of No_of_buses as per the following

conditions :

No_of_travellersNo_of_buses

Less than 20 1

Equal to or more than 20 and less than 40 2

Equal to 40 or more than 40 3

A function ShowTravel( ) to display the content from all the data members on screen.

CHEMISTRY

  1. SOLVE INTEXT QUESTIONS, SOLVED NUMERICAL PROBLEMS OF LESSION I,II,II and IV
  2. Write short notes on:

a)Denaturation of proteins

b) Invert sugar/inversion of sugar

c) Tranquilizers

d) Antibiotics

e) Analgesics

f) Antifertility Drugs

g) Artificial sweetning agents

h) Synthetic detergents

i) Antiseptics and disinfectants

Practice Paper

Class XII CHEMISTRY

Q1State the magnetic behavior after heating of ZnO crystal. (1)

Q2. 10 cm3 liquid A was mixed with 10 cm3 of liquid B. The volume of the resulting solution was found to be 19.9 cm3. What do you conclude ? (1)

Q3. Why is the vapour pressur of a solvent lowered when a non- volatile solute is dissolved in it ? (1)

Q4. What is meant by limiting molar conductivity ? (1)

Q5. From the given graph find the order of the reaction

6. define terms (i) Mole fraction (ii)Van, t Hoff factor (2)

7. In an ionic substance the anions Q form CCP lattice and P are distributed in the tetra and octahedral voids . Determine the formula of the substance. (2)

8. A chemical reaction is of second order with respect of a reactant . How will the rate of the reaction be affected if the concentration of this reaction is ----(i) Doubled (2) Reduced to half of initial. (2 )

9. Draw a plot molar conductivity Vs concentration. why Molar conductivity of both the electrolytes strong well as well weak increases on decreasing concentration (2)

10. (a) why the solids having metal excess defects are semiconductors?

(b) silver crystalizes in FCC lattice each side of the unit cell has a length of 490 pm. What is the radius of an atom of the element. (3)

11. what is activation energy ? The slop for the graph of log K Vs 1/T for the reaction

N2O5 --- 2NO2 + O2

Is -5000. Calculate activation energy of the reaction. (3)

12.stateHenry,s . H2S is a toxic gas with rotten egg smell is used for the qualitative . If solubility of theH2S in water is 0.195 m , calculate Henry, law constant.

13.The electrical resistance of a coloumn of 0.05 mol L-1NaOH solution of diameter 1cm length 50 cm is5.55x10 3 ohm. Calculate its resistivity and molar conductivity. (3)

14 State Raoult for the solution having non-volatile solute in it. Calculate the amount of sodium chloride which must be added to one kilogram of water so that the its freezing point is depressed by 3K. given Kf 1.86 K Kg mol-1 ( Na = 23, Cl = 35.5 ) (2+3)

15(a) What is meant by intrinsic semi conductor? Give one example.

(b) Sodium crystallizes in cubic lattice and the edge of the unit cell is 430 pm. Calculate the number of atom in unit cell , density is 0.96 g/ cm-3. (2+3)16.

16. (a) What is the role of ZnCl2 in dry cell ?

(b) Write the over all reaction in charging of the lead storage battery

(c) Write Nernst equation for the cell reaction:- Cu/ Cu2+ (0.130M) // Ag+ (1.0x10-4M) / Ag

Calculate the e.m. f. of this cell. E0Cu2+/Cu= 0.34V , E0Ag+/Ag = 0.8 v (1+1+3)

17.What is pseudo uni molecular reaction ? Give an example.

The following results have been obtained during kinetic studies of the reaction

2 A + B ---- C + D

Experiment / [A] /mol L-1 / [B] /mol L-1 / Initial rate of formation of D/ mol L-1
I / 0.1 / 0.1 / 6.0 x10-3
II / 0.3 / 0.2 / 7.2 x10-2
III / 0.3 / 0.4 / 2.88 10 -1
Iv / 0.4 / 0.1 / 2.4 x10-2

Determine the rate law and the rate constant for the reaction.

Geography

  1. Do the self-study for the following topics –

Human development