DTEA SR.SEC.SCHOOL LAXMIBAI NGR.

CLASS XII

ENGLISH

ANSWER THE FOLLOWING QUESTIONS:-

1. CMC a leading name in Computer Education requires Hardware Faculty at Ashok Vihar. Write an advertisement

in not more than 50 words for a local newspaper.

2. Suman / Suresh has topped the CBSE 12th Board examination. The family is elated at the achievement and they

decide to have a get-together for all friends. Draft an informal invitation for the get-together.

3. Design a poster in not more than 50 words for your library on the ‘value of books and good reading habits’.

4. The students’ council of your school has organized an excursion to Goa for students of classXII during the summer

vacation. As President of the council, write a notice in not more than fifty words informing the students about this

excursion. Sign yourself as Ravi / Raveena.

5. You have been asked to participate in a debate competition on the topic “Community service should be

introduced in all schools”. Write the speech in about 200 words for or against the motion.

6. ‘Our Good Earth’ an environmental awareness magazine has launched a ‘clean your City’ campaign. Write a

speech to be read out in the morning assembly urging students to participate in the campaign.

7. You are Nitin / Natasha a student of class XII at S.P.N. Public School, Faridabad. The student is required to cope

with lot of pressure in today’s competitive environment. Write a letter to the editor of a national daily highlighting

the increasing stress faced by students and suggest ways to combat the same.

8. write an application for the post of an accountant in Pioneers (Pvt.) Ltd. Co. Hyderabad in response to their

advertisement that appeared in The Times of India dated 1st May, 2018.Prepare a bio data to be enclosed. You are

Shreya/Shreyas.

9. Active member of the Animals Lovers Club of your school which works for preventing cruelty to animals. Write an

article in 150 -200 words for your school magazine emphasising the need to co-exist peacefully with animals. You

are Zaheeda/Zahir of R. K. Senior Secondary School, Patna.

10. You are Rahul, the Headboy of Creative Public School, Delhi. Recently your school hosted the Regional Level

CBSE Science Exhibition. Write a report of this event for your school newletter in about 120 words.

Read the novel ‘ INVISIBLEMAN’

MATHS

CLASS XII

1. Let A= ⟦

⟧ Then express A as a sum of two matrices such that one is symmetric and

the other is skew-symmetric.

2. If A = [

]. Verify that - 4 - 5I =0

3. Using elementary transformations, find the inverse of the matrix [

]

4. For the following matrices A and B , verify that ( ) = . A = [ ] B = [ ]

5. Using elementary transformations, find the inverse of the matrix A = *

+

6. If =[

] and B = [

] find ( )

7. Using elementary transformations, find the inverse of A = [

]

8. Prove using properties |

| = ( )

9. |

( )

( )

( ) | = 2abc ( )

10. |

| =( )( )( )( ) where p is any scalar.

11. Using matrices solve the following system of equations:

X – y + 2z = 7; 3x +4y- 5z =5; 2x – y +3z = 12

12. If A = [

] , find . Using solve the following system of equations:

2x - 3y + 5z =16; 3x + 2y – 4z = -4; x + y – 2z =-3.

13. Solve for x, y, and z:

,

,

14. Using matrices, solve the following system of linear equations: x – y + 2z = 7; 3x + 4y – 5z = 5; 2x –

y +3z = 12

15. Using properties of determinant show that:

[

] = 2 [

]

16. Two schools P and Q want to award their selected students on the values of Discipline, Politeness

and Punctuality. The school P wants to award Rs x each, Rs y each and Rs z each foe the three

respective values to its 3, 2 and 1 students with a total award money of Rs 1000. The school Q

wants to spend Rs 1500 to award its 4, 1 and 3 students on the respective values ( by giving the

same award money for the three values as before) . If the total amount of award for one prize on

each value is Rs 600, using matrices, find the award money for each value. Apart from the above

three values, suggest one more value for awards.

17. Using properties of determinants, prove that |

| =

( )

17. Show that the relation R defined by (a , b) R ( c , d) ⇒ a + d = b + c on the set N x N is an

equivalence relation.

18. Let * be the binary operation on the set Q of rational numbers given as a*b = ( ) , a,b

Q.Find 3*5 and 5*3.

19. Let * be the binary operation on N given by a*b = LCM of a and b. Find the value of 20*16. Is * (i)

commutative (ii) associative?

20. Let f : W → W, be defined as f(x) = x – 1,if x is odd and f(x) = x+ 1 ,if x is even. Show that f is

invertible. Find the inverse of f, where W is the set of all whole numbers.

21. Prove that the relation R in the set A = {5, 6, 7, 8, 9 } given by R = { (a , b) : |a – b| is divisible by 21},

is an equivalence relation. Find all elements related to the element 6.

22. Consider the binary operation* on the set { 1, 2, 3, 4, 5} defined by a * b = min (a ,b).Write the

operation table of *.

23. Prove that

+

=

24. Prove that √

(

) ( )

25. Solve for x : (

) (

) =

26. Prove that : *√ √

√ √ + =

, x (

) .

27. Prove that :

28. (

) (

)

,find the value of x.

29. Show that the relation R in the set of real number defined as R = { (a,b) :a ≤ } is neither

reflexive,nor symmetric, nor transitive.

30. Let A = NxN and * be a binary operation on A defined by ( a, b ) * ((c , d) = (a+c, b+d ). Show that *

is commutative and associative . Also find the identity element for *on A if any.

CHEMISTRY

I. Investigatory Project Prepare an investigatory project of chemistry which should be experiment based. It should be a research based project where every aspect of the topic selected should be discussed in terms of chemistry. The project should have the following key aspects:

Certificate

Acknowledgement

Why this was selected? (related to daily life)

Introduction

Details of the project(research related to the topic)

Experiment (detailed manner including procedure)

Observations

Analysis

Result

Bibliography (mention the links) II. Complete the assignment and back exercise questions of the chapters 1-3. ASSIGNMENT

1. What is meant by the term ‘forbidden zone’ in reference to band theory of solids? 2. ‘Crystalline solids are anisotropic in nature.’ What does this statement means? 3. Write a feature which will distinguish a metallic solid from a ionic solid. 4. Express the relationship between atomic radius(r) and the edge length(a) in the b.c.c. unit cell. 5. What is a semi-conductor’? Describe the two main types of semiconductors and contrast their conduction mechanism. 6. Explain the following with suitable example: (a)Ferromagnetism (b)Ferrimagnetism 7. Define unit cell and coordination number in relation to crystalline solids. 8. Iron has a body centered cubic unit cell with a cell dimension of 286.65pm. The density of iron is 7.874g/cm3 . Use this information to calculate Avogadro’s number.(At. Mass of Fe= 55.845u) 9. Silver crystallizes with face centered cubic unit cell. Each side of this unit cell has a length of 409pm. What is the radius of silver atom? Assume the atoms just touch each other on the diagonal across the face of the unit cell. 10. Tungsten crystallizes in body centered cubic unit cell. If the edge length of the unit cell is 316.5pm, what is the radius of tungsten atom? 11. Calculate the distance between Na+ and Cl- ions in NaCl crystal if its density is 2.165gcm-3 (Molar mass of NaCl=58.5g mol-1 ; NA = 6.022 X 1023 ) 12. A element has a body centered cubic(bcc) structure with a cell edge of 288pm. The density of the element is 7.2g/cm3 . How many atoms are present in 208g of thye element? 13. Define F - centers. 14.What type of stoichiometric defect is shown by

ZnS

AgBr 15.What are the differences between Frenkel and Schottky defect? 16.Define the following terms with suitable examples

Ferromagnetism

Paramagnetism

Ferrimagnetism

12-16 and 13-15 compounds 17.In terms of band theory what is the difference

Between conductor and an insulator

Between a conductor and a semi-conductor 18. A cubic solid is made of two elements X and Y. Atom Y are at the corners of the cube and X at the body centers. What is the formula of the compound? 19.Silver forms ccp lattice and X –ray studies of its crystal show that the edge length of its unit cell is 408.6 pm. Calculate the density of silver (Atomic wt= 107.9u). 20.A cubic solid is made up of two elements P and Q. Atoms of the Q are present at the corners of the cube and atoms of P at the body centre. What is the formula of the compound? What are the co-ordination number of P and Q. 21. What do you mean by Henry’s Law? Write down its applications. 22.Why does sprinkling of salt help in clearing snow covered roads in hilly areas? Explain the phenomenon involved in the process. 23. For the standard cellCu(s)/Cu2+(aq)|| Ag+(aq)/Ag(s)

E0 Cu2+/Cu = +0.34 V

E0 Ag+/Ag =+0.80 V identify the cathode and the anode as the current is drawn from the cell. Write the reaction taking place at the electrodes. Calculate the standard cell potential. 24. Under what condition molality and molarity of a solution are identical. Explain with suitable reason. 25. Addition of HgI2 to KI (aq.) shows decrease in vapour pressure. Why?

26. What will happen to the boiling point of the solution formed on mixing two miscible liquids showing negative deviation from Raoult’s law? 27. Liquid ‘Y’ has higher vapour pressure than liquid ‘X’, which of them will have higher boiling point? 28. When 50 mL of ethanol and 50 mL of water are mixed, predict whether the volume of the solution is equal to, greater than or less than 100 mL. Justify. 29. Which type of deviation is shown by the solution formed by mixing cyclohexane and ethanol? 30. A and B liquids on mixing produce a warm solution. Which type of deviation from Raoult’s law is there? 31. Define cryoscopic constant (molal freezing point depression constant.) 32. Mention the unit of ebulioscopic constant (molal boiling point elevation constant.) 33. If kf for water is 1.86 K kg mol–1, what is the freezing point of 0.1 molal solution of a substance which

34. What is reverse osmosis? Give one large scale use of it.

PHYSICS 1. Do all the assigned investigatory projects. 2. Complete the record files and activities. 3. Answer the following questions from Electrostatics and Current Electricity. 1. Three identical charges each +q are placed at the corners of an equilateral triangle of side d cm. Calculate the force on a +ve charge +2q at the centroid of the triangle.

2. A point charge placed at any point on the axis of an electric dipole at some large distance experiences a force F. Find the force acting on the point charge when its distance from the dipole is quadrupled.

3. N identical spherical drops charged to the same potential ‘V’ is combined to form a big drop. Find the potential of the new big drop formed. 4. An electron is projected with an initial speed of 25×105 m/s directly towards a proton which is at rest. Initially the electron is supposed to be at a fairly large distance from the proton. Find the distance of the electron from the proton when its instantaneous speed becomes twice the initial speed.

5. Two conducting spheres one of radius 6cm and the other of radius 12cm each carrying 3×10-8C are placed very par apart. If these spheres are connected by a conducting wire, find the direction of motion and the magnitude of charge transferred.

6. Can a metal sphere of radius 1cm hold a charge of 1coulomb? Justify your answer.

7. When two capacitors are connected in series, the effective capacitance is 2.4μF and when connected in parallel, the effective capacitance is 10μF. Calculate the individual capacitances

8. You are given three capacitors of value 2μF, 3μF, 6μF. How will you connect them to a resultant capacity of 4μF?

9.An inflated balloon is charged by rubbing with fur. Will it stick readily to a conducting wall or to an insulating wall? Give reason.`

10.An electron moves a distance of 6cm when accelerated from rest by an electric field of strength 2x10-4 N/C. Calculate the time of travel. Given me=9x10-31kg, e=1.6x10-19C. 11.Is the capacitance of a capacitor proportional to the charge Q ? Sketch a graph to show how the capacitance C of a capacitor varies with the charge Q given to it.

12. In a hydrogen atom, an electron moves in an orbit of radius 4.8 x 10-11m with a speed of 2.5 x 10 6 m/s. Find the equivalent current.

13. One metre long metallic wire is broken into two equal parts P and Q. The part ‘P’ is uniformly extended into another wire R. Length of R is twice the length of P and the resistance of R is equal to that of Q. Find the ratio of the resistances of P and R and also the ratio of lengths of P and Q. 14. The area of cross section , length and density of a piece of a metal of atomic weight 60 are 10-6 m2, 1.0 m and 5 x 103 kg/m3 respectively . Find the number of free electrons per unit volume of every atom that contributes one free electron. Also find the drift velocity of electron in the metal when a current of 16A passes through it. Avogadro no.=6x1023 per gram per mole.

15. The length and radii of 3 wires of same metal are in the ratios 2:3:4 and 3:4:5 respectively. They are joined in parallel and included in a circuit having 5A current. Find the current in each case.

16. An electric bulb rated for 500 Watt at 100 V is used in circuit having a 200 V supply. Calculate the resistance R that must be put in series with the bulb s that the bulb delivers 500 watt.

17. A potentiometer wire of length 100 cm has a resistance of 100._ ,W LV connected in series with a resistance and a battery of emf 2V and of negligible internal resistance. A source of emf 10mV is balanced against a length of 40cm of the potentiometer. What is the value of the external resistance?

18. Two wires A and B of the same material and having same length have their cross sectional area in the ratio1:4. What would be the ratio of heat produced in these wires when same voltage is applied across each? 19. Two wires of the same material having lengths in the ratio 1:2 and diameters in the ratio 2:3 are connected in series with an accumulator. Compute the ratio of p.d across the two wires. 20. Observations on a given device yielded the following current – voltage data. Current (A) Voltage(V) 1 19.7 2 39.4 3 59.1 4 78.8 5 98.5 Draw V-I graph using this data. What conclusion can you draw from the graph with regard to ohmic or non-ohmic nature of device?

BIOLOGY

1. a.) Write the scientific names of the two species of filarial worms causing filariasis. b.) How do they affect the body of infected persons? c.) How does the disease spread?

2. Prepare a rough Biochemistry project and submit for approval. 3. Read Chapters 1-4 and 8 thoroughly and practice drawing all the important diagrams in these chapters. 4. Differentiate between

a.) Auto-immune disease and immunodeficiency disease. b.) B lymphocytes and T lymphocytes. c.) Innate immunity and acquired immunity. d.) Cancer cell and normal cell.

5. Placenta acts as an endocrine tissue. Justify. 6. Why is usage of tobacco in any form injurious to health? Explain.

7. Name the plant source of Ganja. How does it affect the body of the abuser?

8. Why do some adolescents start taking drugs? How can the situation be avoided?

9. What are withdrawal symptoms? List four of them.

10. What are interferons? How do they help in developing resistance to infections?

11. Prior to a sports event, blood and urine samples of sports persons are collected for drug tests. Why is there a need to conduct such tests?

a.) Name the drugs the authorities usually look for? b.) Write the botanical names of two plants from which these drugs are obtained.

12. Mention the role of gonadotropins in menstrual cycle. On what day of the menstrual cycle do the

gonadotropins reach a peak. 13. Why are papaya and date plants said to be dioecious whereas cucurbits and coconut palms are

monoecious inspite of all of them bearing unisexual flowers ? 14. Why do internodal segments of sugarcane fail to propagate vegetatively when they are in contact with

damp soil. 15. In whiptail lizards, only females are born generation after generation. There are no males. How is it

possible ? 16. A flower of tomato plant following the process of sexual reproduction produces 240viable seeds.

Answer the following giving reasons. a.) What is the minimum number of pollen grains that must have been involved in the pollination of its

pistil ? b.) What would be the minimum number of ovules present in the ovary ? c.) How many megaspore mother cells were involved ? d.) What is the minimum number of microspore mother cells involved in the above case ? e.) How many male gamates were involved in this case ?

17. a.) Explain the events after pollination leading to the formation of a seed in angiosperms. b.) Mention the ploidy levels of the cells of different parts of an albuminious seed.

18. Describe the life cycle of malarial parasite. Draw diagrams to illustrate.

19. Study the flow chart. Name the hormone involved at each stage and explain their role.

Ovulation ↓ Pregnancy ↓

Placenta ↓ Foetal Growth ↓ Parturition ↓ Lactation

20. Given below is a flow chart showing ovarian changes during menstrual cycle. Fill in the spaces giving the

name of the hormone responsible for the events shown. Primary follicle

↓ a Graafian follicle ↓ b Ova ↓ c Corpus luteum

21. Draw a neat diagram of the female reproductive system and label the parts assocaitaed with the

following.

a. Production of gamates. b. Site of fertilization. c. Site of implantation. d. Birth canal

22. Expand the following abbreviations.

a.) ZIFT b.) PEN c.) WHO d.) ART e.) CDRI f.) GIFT g.) IUCI h.) AI i.) MMR j.) RCH

k.) IUCI l.) STD m.) MTP n.) AIDS o.)IVF p.) IUT q.) GnRH r.) FSH s.) ET t.) LH u.) hCG v.) HIV w.) MMC x.) ICSI y.) hPL z.) CuT

23. How many linkage groups are present in

a.) Human beings b.) Drosophila c.) In an organism where n = 34

24. In our society a woman is often blamed for not bearing a male child. Do you think it is right ? Justify.

25. A man having blood group A is married to a woman having blood group B. Work out the genotype of

both man and wife, if one of their children is born with blood group O. What is the possible genotype of the other offsprings ?

26. A normal male marries a carrier female ( haemophilia). What is the possibility of male child being

haemophilic and what is the probability of female carrier ? What is the probability of a females child which is infected ?

27. Plan an experiment and prepare a flow chart of the

a.) Steps that you would follow to ensure that seeds are formed only from the desired pollen grains. Name the type of experiment that you carried out.

b.) Write the importance of such experiments. 28. Prepare thoroughly for your presentation on the topic allocated to you.

COMPUTER SCIENCE

Q1. Find out the reserved keywords out of the following:

For, while, New, Istname, INT , case, include.

Q2. Which C++ header files(s) are essentially required to be included to run / execute the following C++ source

code ?

void main( )

{

Char Text[ 50 ];

Strcpy (Text, “ CBSE”);

Puts(Text);

}

Q3. Rewrite the following program after removing the syntax error(s), if any.

Underline each correction.

Note : Assume all required header files are already being included in the program.

#include< iostream.h >

Void main( )

{

One = 10, Two = 20 ;

func (One ; Two ) ;

func (Two) ;

}

Void fun (int a, int b = 20)

a = a+ b ;

Count<<a>>b ;

}

Q4. Find the output of the following program:

Note : Assume all the header files are already being included in the program.

#include<iostream.h >

Struct SPORT

{

Int Score, Bonus;

} ;

Void Play(SPORT &S , int N=10)

}

Void main( )

{

SPORT S = { 110, 50} ;

Play ( S, 10 ) ;

Cout<<S.Score<<”: “<<S.Bonus<<endl ;

Play(S,15 ) ;

Cout<<S.Score<<” : “<<S.Bonus<<endl ;

}

Q5. Write the output of the following program:

Note : Assume all the header files are already being included in the program.

#include<iostream.h >

Class Inc

{

Private :

Unsigned int count ;

Public :

Inc( )

{

Count = 0 ;

}

Void inc_count ( )

}

Count++ ;

}

Int get_Count( )

}

return Count ;

}

} ;

Void main ( )

{

Inc C1, C2;

Count<<”\tC1 = “<<C1.get_count( ) ;

Count<<”\tC2 = “<<C2.get_count( ) ;

C1.inc_count( );

C2.inc_count( );

Count<<”\tC1 = “<<C1.get_count ( ) ;

Count<<”\tC2 = “<<C1.get_count ( ) ;

}

Q6. Differentiate between a data type struct and a data type class in C++.

Q7. Define a class Train in C++ with the following description:

Private members

(i) A data member Trainnumber of type integer (ii) A member Destination of type string (iii) A data member Distance of type string (iv) A data member Fuel of type float

(v) A member function CAL( ) to calculate the value of fuel as per the following criteria : Distance Fuel

<= 500 300

More than 500 && <= 1000 700

More than 1000 1500

(i) A function INPUT( ) to allow user to enter values for Trainnumber, Destination, Distance and call function CAL ( ) to calculate the quantity of fuel.

(ii) A function DISPLAY( ) to allow user to view the content of all the data members. Q8. Differentiate between call by value and call by reference. Give one example of each.

Q9. Which C++ header file(s) will be essentially required to be included to run/execute the following C++ code?

Void main( )

{

Char Info * + = “Indian Army “ :

For(int I=5; <strlen(Info) ; I++)

Puts(Info);

}

Q10. Rewrite the following program after removing the syntactical errors (if any). Underline each correction.

Note : Assume all the header files are already being included in the program.

Include iostream.h

Main( )

{

Float x, y, z :

Cout<<”Enter two numbers” ;

Cin>>a>>b

Cout<<”The numbers in reverse order are”<<b, a;

}

Q11. Find the output of the following program :

Note : Assume all the header files are already being included in the program.

#include<iostream.h>

Struct Play

{

Char Arr [ 20 ]; int n ;

} ;

Void main ( 0

{

Play P = , “ Magic” , 500- ;

P.Arr * 4 + = ‘ Q ‘ ;

P.Arr * 2+ = ‘ L’ :

P.n += 50;

Cout<<P.Arr<<P.n<<endl ;

Play R = P;

R.n -= 120;

Cout<<R.n<<endl ;

}

12. Write the MySQL Command to Create a table for CUSTOMER with follow specification :

Column Name Data Type Constraint

Cust_ID INTEGER (4) PRIMARY KEY

Cust_Name VARCHAR (25) NOT NULL

Cust_Address VARCHAR (25)

Pin_Code BIGINT (10)

Cust_Phone BIGINT (10)

13. Consider the following two tables :

Table Classes

S_NO. NAME

1 BBCA

2 BSC

3 MSC

Table Subject

S_NO. NAME

1 JAVA

2 C++

3 ORACLE

Give output of the following query :

SELECT CLASSES.CLASS_NAME, SUBJECTS.SUB_NAME

FROM CLASSES JOIN SUBJECTS

ON CLASSES.S_NO.=SUBJECTS.S_NO;

14. How will you drop a column from a table ? 15. Differentitate between NULL and NOTNULL. 16. What is a datatype ? Name some data types available in MySQL. 17. What do you mean by Cartesian product ? 18. What is a table alias?

19. What happens to the current transaction if a START TRANSACTION is executed ?

20. Which has “all-or-none” Property in database transaction ? 21. What is MySQL ? Discuss the components of MySQL. 22. What is a relation ? What is the different between a tuple and an attribute ? 23. What is the role of following command : 24. What happens when “ROLLBACK” Command is issued in a transaction process ? 25. Write two example of

(i) DML command (ii) TCL command

26. What are the basic elements of MySQL ? Write down the difference between table and column con

NOTE:-

HOLIDAY H.W.Should be done in separate note book/folder for all the subjects.