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TITIKSHA PUBLIC SCHOOL

SESSION 2018-19

SUMMER BREAK HOMEWORK

CLASS XII

ENGLISH

INSTRUCTIONS:

• Write the answers carefully in a legible handwriting which should be clear enough to read

• The work should be completed in Homework Notebooks

• All the answers should be marked with date

Letter Writing

1. During summer vacation, everyone looks for a long gateway, away from the scorching

high temperatures and hustle-bustle of the city life. Write down a letter to your friend for

place, evoking interest to visit in summer in India .You are Mohit / Mohita.

2. You are Prakash / Prakshi. You saw an advertisement regarding a course for training and

preparing students for TOEFL-Test of English as a Foreign Language. You wish to join the

course. Write a letter to the Course Director of ‘EASY ENGLISH, MGR Marg, Chennai,

inquiring about all the details that you require.

3. You are Daisy/Danish, a student of Class XII of St John’s School, Delhi Cantt, New Delhi.

You have come across textbooks supposedly published by NCERT but without their logo,

at revised prices indicated by rubber stamp or a sticker. Write a letter to Chairman

NCERT, New Delhi, complaining about the pirated editions and the manipulated prices.

4. You are Mohit Chaudhary of Western House, Green Lane, Mumbai. You have seen an

advertisement in the newspaper looking for salesboys to work at the local Mcdonald outlet.

You are interested and decided to apply. Write the letter applying for job giving your

personal details.

Article Writing

1. The Existence of the Generation Gap is a Reality

2. Ban Religion, Save the Country

3. Community Service in Schools

4. How to Curb Bullying in Schools ?

5. Growing Urbanization is a doom for Nature

Speech/Debate Writing

1. Rights and Responsibilities of a Citizen

2. How the Youth can Curb Corruption in India

3. Pen is Mightier than a Sword

4. Importance of Secular Nature of our Country

5. Negative effects of Mall Culture on the Youth

Literature

1. Write down the character sketch of the following with reference from the novel ‘The

Invisible Man’(120-150 words)

• Griffin

• Mrs Hall

• Mr Teddy Henfrey

• Mr Cuss

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• Mr Bunting

• Mr Jaffers

• Mr Marvel

• The Hunchback

• Dr Kemp

• Colonel Adey

• Mr Heelas

2. Why did HG Wells put an epilogue in the novel ‘The Invisible Man’?

3. What message does the story ‘The Last Lesson’ carry? How relevant is it today?(120-150

words)

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PHYSICS

Ray Optics and Optical Instruments

Section A (1 mark

each) Question 1. Write the value of angle of reflection for a ray of light falling normally on a

mirror.

Question 2. How does the dispersive power of glass prism change when it is dipped in water?

Question 3. Light falls from glass to air. Find the angle of incidence for which the angle of

deviation is 90°.

Question 4. Name the phenomenon due to which one cannot see through fog.

Question 5. What is the ratio of sini and sinr in terms of velocities in the given figure. Question 6. What is the shape of fringes in young’s double slit experiment?

Question 7. A equiconcave lens of focal length 15 cm is cut into two equal halves along

dotted line as shown in figure. What will be new focal length of each

half

Question 8. For the same angle of the incidence the angle of refraction in three media A, B and

C are 15°, 25° and 35° respectively. In which medium would the velocity of light be minimum?

Question 9. What is the phase difference between two points on a cylindrical wave front?

Question 10. What is the ‘power’ of plane glass plate?

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Question 11. Show with the help of diagram, why a beam of white light passing through a

hollow prism does not give spectrum.

Question 12. How does focal length of lens change when red light incident on it is replaced

by violet light?

Question 13. A myopic person prefers to remove his spectacles while reading a book.

Why? Question 14. Lower half of the concave mirror is painted black. What effect will this have on

the image of an object placed in front of the mirror?

Question 15. An air bubble is formed inside water. Does it act as converging lens or a

diverging lens? [Diverging lens]

Question 16. A water tank is 4 meter deep. A candle flame is kept 6 meter above the level. µ

for water is 4/3. Where will the image of the candle be formed? [6m

below the water level].

Section B (2 marks each)

Question 1. A near sighted person can clearly see objects up to a distance of 1.5m. Calculate

power of the lens necessary for the remedy of this defect. (P = – 0.67D) Question 2. A person can adjust the power of his eye lens between 50D and 60D. His far point

is infinity. Find the distance between retina and eye lens.

Question 3. Calculate the value of θ, for which light incident normally on face AB grazes along

the face BC.

Question 4. Name any two characteristics of light which do not change on polarisation.

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Question 5. Complete the path of light with correct value of angle of emergence.

Question 6. Define diffraction. What should be the order of the size of the aperture to observe

diffraction.

Question 7. Show that maximum intensity in interference pattern is four times the intensity due to

each slit if amplitude of light emerging from slits is same.

Question 8. Two poles-one 4m high and the other is 4.5 m high are situated at distance 40m

and 50m respectively from an eye. Which pole will appear taller? Question 9. S1 and S2 are two sources of light separated by a distance d. A detector can move along S2P perpendicular to S1S2. What should be the minimum and maximum path difference at the detector?

Question 10. If a jogger runs with constant speed towards a vehicle, how fast does the image of

the jogger appear to move in the rear view mirror when

(i) the vehicle is stationery (ii) the vehicle is moving with constant speed.

Question 11. A person looking at a mesh of crossed wire is able to see the vertical wire more

distinctly than the horizontal wire. Which defect he is suffering from? How

can this defect be corrected?

Question 12. Is optical density same as mass density? Give an example.

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Question 13. When does (i) a plane mirror and (ii) a convex mirror produce real image of

objects.

Question 14. A virtual image cannot be caught on a screen. Then how do we see it?

Question 15. Draw a diagram to show the advance sunrise and delayed sunset due to atmospheric refraction.

Question 16. Define critical angle for total internal reflection. Obtain an expression for

refractive index of the medium in terms of critical angle.

Question 17. The image of a small bulb fixed on the wall of a room is to be obtained on the

opposite wall ‘s’ m away by means of a large convex lens. What is the

maximum possible local length of the lens required?

Question 18. The angle subtended at the eye by an object is equal to the angle subtended at the

eye by the virtual image produced by a magnifying glass. In what sense then

does magnifying glass produce angular magnification?

Question 19. Obtain relation between focal length and radius of curvature of (i) concave

mirror (ii) convex mirror using proper ray diagram.

Question 20. Two independent light sources cannot act as coherent sources. Why? Question 21. How is a wave front different from a ray? Draw the geometrical shape of the

wavefronts when.

(i) light diverges from a point source,

(ii) light emerges out of convex lens when a point source is placed at its

focus.

Question 22. What two main changes in diffraction pattern of single slit will you observe

when the monochromatic source of light is replaced by a source of white

light.

Question 23. You are provided with four convex lenses of focal length 1cm, 3cm, 10cm and 100

cm. Which two would you prefer for a microscope and which two for a

telescope.

Question 24. Give reasons for the following

(i) Sun looks reddish at sunset

(ii) clouds are generally white

Question 25. Using Huygens Principle draw ray diagram for the following

(i) Refraction of a plane wave front incident on a rarer medium

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(ii) Refraction of a plane wave front incident on a denser medium.

Question 26. Water (refractive index μ) is poured into a concave mirror of radius of curvature ‘R’

up to a height h as shown in figure. What should be the value of x so that the

image of object ‘O’ is formed on itself?

Question 27. A point source S is placed midway between two concave mirrors having equal focal

length f as shown in Figure. Find the value of d for which only one image is formed.

Question 28. A thin double convex lens of focal length f is broken into two equal halves at the

axis. The two halves are combined as shown in figure. What is the focal length of combination in

(ii) and (iii). Question 29. How much water should be filled in a container 21 cm in height, so

that it appears half filled when viewed from the top of the container. (aμω =

4/3)?

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Question 30. A ray PQ incident on the refracting face BA is refracted in the prism BAC as shown

in figure and emerges from the other refracting face AC as RS such that AQ =

AR. If the angle, of prism A = 60° and μ of material of prism is √3 then find

angle θ. Section C (3 marks each)

Question 1. Using mirror formula show that virtual image produced by a convex mirror is

always smaller in size and is located between the focus and the pole.

Question 2. Obtain the formula for combined focal length of two thin lenses in contact,

taking one divergent and the other convergent.

Question 3. Derive snell’s law on the basis of Huygen’s wave theory.

Question 4. A microscope is focussed on a dot at the bottom of the beaker. Some oil is poured into

the beaker to a height of ‘b’ cm and it is found that microscope has to raise

through vertical distance of ‘a’ cm to bring the dot again into focus. Express

refractive index of oil is terms of a and b.

Question 5. Define total internal reflection. State its two conditions. With a ray diagram show how does optical fibres transmit light.

Question 6. A plane wave front is incident on (i) a prism (ii) A convex lens (iii) a concave mirror. Draw the emergent wavefront in each case.

Question 7. Explain with reason, how the resolving power of a compound microscope will

change when (i) frequency of the incident light on the objective lens is

increased. (ii) focal length of the objective lens is increased. (iii) Aperture of

objective lens is increased.

Question 8. Derive Mirror formula for a concave mirror forming real Image.

Question 9. Two narrow slits are illuminated by a single monochromatic sources.

(a) Draw the intensity pattern and name the phenomenon

(b) One of the slits is now completely covered. Draw the intensity pattern now

obtained and name the phenomenon.

Question 10. Explain briefly (i) sparkling of diamond (ii) use of optical fibre in communication.

Question 11. Using appropriate ray diagram obtain relation for refractive index of water in terms of

real and apparent depth.

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Question 12. Complete the ray diagram in the following figure where, n1, is refractive index of medium

and n2 is refractive index of material of lens.

Question 13. A converging beam of light is intercepted by a slab of thickness t and refractive

index μ. By what distance will the convergence point be shifted? Illustrate the answer.

Question 14. In double slit experiment SS2 is greater than SS1 by 0.25λ. Calculate the path

difference between two interfering beam from S1 and S2 for minima and maxima on the point P

as shown in Figure.

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Section D (5 marks each)

Question 1. With the help of ray diagram explain the phenomenon of total internal reflection. Obtain the

relation between critical angle and refractive indices of two media. Draw ray diagram

to show how right angled isosceles prism can be used to:

(i) Deviate the ray through 180°.

(ii) Deviate the ray through 90°.

(iii) Invert the ray.

Question 2. Draw a labelled ray diagram of a compound microscope and explain its working. Derive an

expression for its magnifying power.

Question 3. Diagrammatically show the phenomenon of refraction through a prism. Define angle of

deviation in this case. Hence for a small angle of incidence derive the relation δ = (μ –

1) A.

Question 4. Name any three optical defects of eye. Show by ray diagram :

(i) Myopic eye and corrected myopic eye.

(ii) Hypermetropic eye and corrected hypermetropic eye.

Question 5. Define diffraction. Deduce an expression for fringe width of the central maxima of the

diffraction pattern, produced by single slit illuminated with monochromatic light

source.

Question 6. What is polarisation? How can we detect polarised light? State Brewster’s Law and deduce

the expression for polarising angle.

Question 7. Derive lens maker formula for a thin converging lens.

Question 8. Derive lens formula

(a) a convex lens,

(b) a concave lens.

Question 9. Describe an astronomical telescope and derive an expression for its magnifying power using

a labelled ray diagram.

Question 10. Draw a graph to show the angle of deviation with the angle of incidence i for a

monochromatic ray of light passing through a prison of refracting angle A. Deduce

the relation

µ =

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Question 11. State the condition under which the phenomenon of diffraction of light takes place Derive

an expression for the width of the central maximum due to diffraction of light at a

single slit. Also draw the intensity pattern with angular position.

NUMERICALS

Question 1. An object of length 2.5cm is placed at a distance of 1.5f from a concave mirror where f is

the focal length of the mirror. The length of object is perpendicular to principal axis.

Find the size of image. Is the image erect or inverted?

Question 2. Find the size of image formed in the situation shown in figure.

Question 3. A ray of light passes through an equilateral prism in such a manner that the angle of

incidence is equal to angle of emergence and each of these angles is equal to 3/4 of

angle of prism. Find angle of deviation. [Ans.: 300]

Question 4. Critical angle for a certain wavelength of light in glass is 30°. Calculate the polarising angle

and the angle of refraction in glass corresponding to this.

Question 5. A light ray passes from air into a liquid as shown in figure. Find refractive index of liquid.

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Question 6. At what angle with the water surface does fish in figure see the setting sun?

Question 7. In the following diagram, find the focal length of lens L2. [40 cm] Question 8. A hypermetropic person whose near point is at 100 cm wants to read a book. Find the

nature and power of the lens needed. Question 9. For a man shortest distance of distinct vision is 20 cm. What will be the type and power

of lens which would enable him to read a book at a distance of 60 cm? Question 10. Using the data given below, state which two of the given lenses will be preferred to

construct a (i) telescope (ii) Microscope. Also indicate which is to be used as

objective and as eyepiece in each case.

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Question 11. Two thin converging lens of focal lengths 15 cm and 30 cm respectively are held in

contact with each other. Calculate power and focal length of the combination.

Value Based Questions

Question 1. A child is observing a thin film such as a layer of oil on water show beautiful colours

when illuminated by while light. He feels happy and surprised to see this. His

teacher explains him the reason behind it. The child then gives an example of

spreading of kerosene oil on water to prevent malaria and dengue.

(i) What value was displayed by his teacher?

(ii) Name the phenomenon involved?

Question 2. Ravi is using yellow light in a single silt diffraction experiment with sit width of 0.6 mm.

The teacher has replaces yellow light by x-rays. Now he is not able to observe the

diffraction pattern. He feels sad. Again the teacher replaces x-rays by yellow light

and the differaction patter appears again.

(i) Which value is displayed by the teacher?

(ii) Give the necessary condition for the diffraction.

CHEMISTRY

Do all the questions from NCERT exampler for the following chapters:-

(i)solid state

(ii)solutions

(iii)chemical kinetics

(iv)surface chemistry

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MATHEMATICS

Revise the following chapters from exemplar :

❖ Chapter 1: Relations and Functions

❖ Chapter 2: Inverse trigonometric functions

❖ Chapter 3: Matrices

❖ Chapter 4: Determinants

❖ Chapter 5: Continuity and differentiability

BIOLOGY

QUESTION BANK

Answer the following questions

1. Name the two kinds of linkage.

2. Write Mendel’s dihybrid ratio of phenotypes.

3. Who proposed chromosome theory of inheritance?

4. Who shows that the gene lie in the chromosome?

5. Which Mendel’s law of inheritance is universally acceptable without any

exception?

6. Write any three abnormalities linked with sex chromosomes.

7. List the main points of chromosome theory of inheritance.

8. What do you mean by Pedigree analysis?

9. Give a detailed account of following:

(a) Sickle Cell Anaemia

(b) Haemophilia

(c) Phenylketonuria

10. Define the terms intron and exon.

11. List the characteristics of a gene

12. What is central dogma reverse?

13. Differentiate between a template strand and coding strand of DNA

14. Write the full form of VNTR. How is VNTR different from probe?

15. Describe the structure of tRNA.

16. Genetic code is specific and nearly universal. Justify.

17. Give the applications of “finger printing”.

18. How does replication occur in DNA?

19. Mention two functions of codon AUG.

20. Explain the phenomenon of Industrial Melanism. What does it suggest?

21. Differentiate between Convergent and Divergent Evolution

22. What are homologous organs? How do they provide evidence of evolution?

23. What do you understand by “survival of the fittest”?

24. What is Adaptive radiation? Explain with example

25. What is Hardy Weinberg Equilibrium? Give its equation? Is it applicable under all

conditions in nature?

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- Revise Chapter 5 to 7

- Reattempt periodic test in the notebook

- Complete your investigatory projects along with case study

COMPUTER SCIENCE

● Revise Ch- 1 to 6.

● Reattempt periodic test in the notebook with corrections.

● Attempt all questions of Section 1, 2 from Question Bank.

ENGINEERING GRAPHICS

Q1- Construct an isometric scale of 80mm length with sub-divisions.

Q2-Draw all prisms , pyramid & Frustums base side =50mm and axis length=70mm.

Q3-Draw top and front view of Hexagonal nut & Square nuts M=30mm.

Q4- Draw front &LHS views of Hexagonal headed bolt and Square bolt ( i e. Shank

length=120mm, thread length=80mm and M=30mm).

Q5- Assembly :- draw all views according to book, give all dimension and projection symbol.

1)OPEN BEARING

2)BUSH BEARING

3)SPIGOT &SOKET JOINT.

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ACCOUNTANCY

PART B: Financial Statement Analysis

Q.1 Prepare Specific Project 1.

a. Meaning of Ratio Analysis.

b. Importance of Ratio Analysis.

c. Limitations of Ratio Analysis.

d. Meaning of Accounting Ratios.

e. Meaning of Current Ratio, its significance and formula.

f. Meaning of Quick Ration, its significance and formula.

g. Meaning of Debt to Equity Ratio, its significance and formula.

h. Meaning of Working Capital Turnover ratio, its significance and formula.

i. Meaning of Net Profit Ratio, its significance and formula.

j. Meaning of Return on Investment Ratio, its significance and formula.

Q.2 Prepare Specific Project 2.

a. Meaning of Cash Flow Statement.

b. Importance of Cash Flow Statement.

c. Limitations of Cash Flow Statement.

Q.3 Prepare Comparative Statement and Common Size Statement for Evaluation Ques.1-8.

Q.4 Calculate Accounting Ratios for practical problems no. 1-146.

Q.5 Prepare Cash Flow Statement for practical problems no. 40-60.

BUSINESS STUDIES

TASK I

Students are supposed to select two units out of four and are required to make one project from

each selected unit. (consist of two projects of 20 marks)

1. Elements of Business Environment

2. Principles of Management

3. Stock Exchange

4. Marketing

Project guidelines are given in G.S.Alag and also discussed in class.

TASK II

Revise the following chapters and complete “TEST YOURSELF” from G.S.Alag for each

chapter. Make a separate notebook for revision work.

Chapter 1 Nature and significance of management

Chapter 2 Principles of Management

Chapter 11 Marketing Management

Chapter 12 Consumer Protection

ECONOMICS

1. Revise the following chapters:

a. Introduction

b. Consumer’s Equilibrium

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c. Theory of Demand

d. Price Elasticity of Demand

e. Money & Banking

f. Government Budget

g. Balance of Payments

h. Foreign Exchange

2. Complete the following assignments given in the class:

1. Assignment 1: Money & Banking

2. Assignment 2: Government Budget

3. Assignment 3: Consumer’s Equilibrium- Utility Approach

4. Assignment 4: Consumer’s Equilibrium- IC Analysis

5. Assignment 5: Theory of Demand

6. Assignment 6: Foreign Exchange

7. Assignment 7: Central Problems of an Economy

3. Complete back exercise unsolved practicals of Price Elasticity of Demand (1- 84)

4. Prepare project according to the topic and guidelines given in the class.

FOOD PRODUCTION

Written work : Solve all exercises from 1st and 2nd chapter for F. P in your respective note

books.

To Learn :

Learn q/a of chapter 1 and 2

GEOGRAPHY

1) Field survey (pollution)

Students need to follow the following instructions

● Acknowledgement

● Certificate

● Introduction

● Conceptual framework

● Aims & Objectives

● Questionnaire Data collection

● Data collection

● Processing and Tabulation of Data

● Data Analysis

● presentation in graphs

● Conclusion

● suggestions

2) Do the given assignments from the fundamentals of human geography from chapter 1,2,3,4

and 5.

3) Do the given assignments from India, people and economy from chapter 1, and 2.

4) Practice map related to the chapters mentioned above.

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HOME SCIENCE

1.Identify the problems of adjustments of adolescents with the help of a tool and makereport

2. Spend a day with an aged person (at home /old age home) and observe their needs and

problems, write a report.

3. List and discuss areas of agreement and disagreement of self with a) mother b) father c)

siblings d ) friends e) teacher

4. Visit any one place (home/restaurant/ school canteen) and observe its measure for hygiene and

safe drinking water.

5.Illustrate elements of art and principles of design using paper or cloth and evaluate them.

6.To inspect a food label and evaluate if it has Specification by FSSAI

7.Prepare one label each of item bearing FPO, ISI, Agmark

ASSIGNMENT

1.Other than fssai, mention the standard marks you should

check while buying a bag of wheat flour and a bottle of mango

pickle.

2 List any two facilities which are provided for the workers

at the worksite, under MGNREGA.

3.Draw suitable symbols for the care label of a dress that

indicates that ‘it should not be tumble dried’ and ‘should be ironed at low heat’.

4 What could be two conditions under which the Food Safety and

Standard Authority of India (fssai) has declared that has been declared

adulterated? List two health hazards of consuming such jaggery.

5 Identify eight such areas in the kitchen where unhygienic conditions

can develop and hence need your attention

6 The water in which you soaked the Bengal gram turned yellow .You also find that the shape of

the dal is not uniform . What in your opinion is the reason for these two observations ?Name two

more foods you have noticed which have same problem . What are the health hazards of

consuming such foods?

7 Most villages are suffering from swelling in feet and legs. The Doctor has described it is due to

consumption of some adulterant in their food? What could be the adulterant? Mention other

symptoms associated with this adulterant. Suggest the three ways by which villagers can

safeguard themselves from buying adulterated food.

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8 Name a suitable chemical which can be used to purify drinking water when you are travelling.

Describe the procedure of purifying water in three steps.

9 Give three suggestions with diagram to your tall and thin brother to choose a suitable design of

kurta for him

10 Give two features of DWCRA

INFORMATICS PRACTICES

● Complete all lab exercises of Chapter 8 to 10 and Chapter 3 in file.

● Revise Ch-3 for all the topics of class XI.

● Attempt the Periodic test paper in the notebook with corrections.

PHYSICAL EDUCATION

1. Revision of covered chapters.

2. Practical file

• Practical-1:Modified AAHPER administration for all items.

• Practical-2: Conduct Barrow 3 Item Test on 10 students.

• Practical-3: Procedure for Asanas, Benefits & Contraindication for any five Asanas

for each lifestyle disease.

• Practical-4: Procedure for administering Senior Citizen Fitness Test for 5 elderly

family members.

• Practical-5: volleyball. Labelled diagram of field & equipment (Rules, Terminologies

& Skills).

• Practical-5 National highest award