कें द्रीय विद्यालय क्र.2,दिल्ली छािनी (वितीय पाली)

ग्रीष्मािकाश गृहकायय सत्र 2017-18 ( वहन्िी )

कक्षा बारहिीं : हहिी (ऐवछछक)

1) पढ़ाई गईं कविताओं की सप्रसंग व्याख्या कीवजए |

2) पढाए गए गद्य भाग से दकन्ही चार गद्यांश की साप्रसंग व्याख्या कीवजए |

3) जनसंचार के 50 प्रश्न उत्तर सवहत तैयार कीवजए |

4) िो अपठित गद्यांश और िो अपठित काव्यांश के प्रश्न हल कीवजए |

5) पढाए गए गद्य पािों एिं काव्य भाग से प्रत्येक से चार –चार ऐसे प्रश्न

तैयार करें जो पाठ्य-पुस्तक के प्रश्न –अभ्यास में न दिया गया हो |

कक्षा बारहिीं : हहिी (केवन्द्रक)

1. जनसंचार के 50 प्रश्न उत्तर सवहत तैयार कीवजए |

2. िो अपठित गद्यांश और िो अपठित काव्यांश के प्रश्न हल कीवजए |

3. पढ़ाई गईं कविताओं के काव्य सौन्ियय वलवखए |

4. पढाए गए गद्य पािों एिं काव्य भाग से प्रत्येक से चार –चार ऐसे प्रश्न

तैयार करें जो पाठ्य-पुस्तक के प्रश्न –अभ्यास में न दिया गया हो |

5. दकन्ही चार समसामवयक विषयों पर फीचर तैयार कीवजए |

ENGLISH Class XII ENGLISH-Core Home Work Summer Vacation 2017

Q1 Write and learn all the question-answers of the following lessons: My Mother at Sixty-Six, The Tiger King, Last Lesson, Lost Spring Q2 Read ‘The Invisible Man’ and prepare notes for first seven chapters.

Q3 You want to dispose off your car, as you are going abroad. You are Harish of No. 10, Kailashganj and Lucknow. Draft an advertisement to be published in the daily, ‘The Hindustan Times’, under classified Columns. Q4 Your school (Amar Vidyalaya), Bangalore is organizing a cultural evening to collect funds for the slum children. The Vice-Chancellor, Bangalore University has consented to be the Chief Guest on the occasion. Draft a notice in this connection to be displayed on your school notice board. Imagine you are the Rakesh Tilak ,Cultural Secretary of your school. (Word limit: 50 words) Q5 On behalf of Department of Environment, Bangalore Administration, draft a Poster on the detrimental consequences of burning leaves and garbage upon the environment and also issuing a warning of the punishment to those indulging in the same. Q6 Recently you visited your ancestral home in a village in Gujarat. You were elated and strongly felt the necessity to hold on to the roots of our modern life, which lie in our villages. Write an article for your school magazine. You are Chetna / Chirag, Cultural Secretary of your school. Q7 Write a letter to the librarian of the District Library in your town asking for details regarding membership. Also ask about the timings and rules and regulations of the library. Q8 Your school is organizing the prestigious KVS National Level Social Science Exhibition in its premises. Draft an invitation in not more than 50 words giving all essential details. Q9 The Readers’ Club of your school visited schools for the less privileged to encourage and promote reading habits. Besides donating books, the members also distributed books collected from individuals and organizations. Write a report in 100 – 125 words about your campaign and its success. You are Anush / Anu, the Club Secretary. Q10(A) Read the passage given below for Note making : The Trail of smoke in most cases inevitably leads to school. And college days-those adolescent times when mere lighting up gave them the thrill of indulging in the prohibited. And yes, they weren.t mama.s boy (or girls) anymore; they were macho and grown up beyond listening to nannies. Or so they thought, till they got addicted. There is a clear link between the youth and tobacco addiction. Statistics reveal that many children are initiated into the habit of smoking at the tender age of 10 years, according to Dr. Srinath Reddy, a researcher-activist. That.s why it makes sense to stop them young, when they are vulnerable to peer pressure. Smoking, which often starts as an experiment in the company of friends often transforms into addiction. According to the Non-Smoker.s Health Protection Act 1997 nobody is allowed to store, sell or distribute cigarettes, beedies or any other tobacco product within an area of 100 m around colleges, schools and other educational institutions. The Indian Parliament passed another comprehensive legislation, the Cigarette and Other Tobacco Products Act, a few years ago banning the sale of tobacco products to minors. Has that made any difference? .You have to go to north campus to see if any law is followed.. Many students even argue that it is a matter of personal choice. .Once in college, a student is old enough to take decisions. It is clearly mentioned on cigarette packs that .smoking is injurious to health. and after that if someone smokes, it is completely the individual.s choice,. says Manu Singh, a student at JNU. Sad reality is that nothing has been able to stop students from smoking in schools and colleges. It.s fashion. The law enforcement agencies takes refuge behind pleas like they have large areas to cover with a small term. Their strength, they say, is not adequate to enforce laws. .Sometimes people pay the fine (Rs 200), which is hardly a big amount. It universities and colleges, raids are not possible. With just one person

from the police, it becomes impossible to control them,. said Dr. M.D. Thapa, Chief District Medical Officer, Northwest district. Advocate Ashok Agarwal does not buy the argument According to him, there is a clear lack of interest on the part of the lawmakers. .The police and the administration have their own priorities hence they have little time to look into these sensitive issues. The situation in this case is that of accepted and agreed violation where just nobody is bothered.. he says. The one answer the experts agree on is; the government. .There is no effort to implement the laws,. complains advocate Ashok Agarwal. When society does not care, the government becomes duty-bound to make them care. .There is a direct link between the youth and tobacco addiction. They are the key targets for the MNCs,. says Bijon Mishra, a social activist involved with the NGO, Voice. While society and its institution ignore those mischievous puffs in school canteens, the biggest beneficiaries are the tobacco companies. (a) On the basis of your reading of the above passage make notes on it using recognizable abbreviations (minimum 4) wherever necessary. Use a format you consider appropriate Supply a suitable Title. (5 Marks) (b) Write a summary of the passage in about 80 words. (3 Marks)

(B) Read the passage given below : 1. Maharana Pratap ruled over Mewar only for 25 years. However, he accomplished so much grandeur during his reign that his glory surpassed the boundaries of countries and time turning him into an immortal personality. He along with his kingdom became a synonym for valour, sacrifice and patriotism. Mewar had been a leading Rajput kingdom even before Maharana Pratap occupied the throne. Kings of Mewar, with the cooperation of their nobles and subjects, had established such traditions in the kingdom, as augmented their magnificence despite the hurdles of having a smaller area under their command and less population. There did come a few thorny occasions when the flag of the kingdom seemed sliding down. Their flag once again heaved high in the sky thanks to the gallantry and brilliance of the people of Mewar. 2. The destiny of Mewar was good in the sense that barring a few kings, most of the rulers were competent and patriotic. This glorious tradition of the kingdom almost continued for 1500 years since its establishment, right from the reign of Bappa Rawal. In fact only 60 years before Maharana Pratap, Rana Sanga drove the kingdom to the pinnacle of fame. His reputation went beyond Rajasthan and reached Delhi. Two generations before him, Rana Kumbha had given a new stature to the kingdom through victories and developmental work. During his reign, literature and art also progressed extraordinarily. Rana himself was inclined towards writing and his works are read with reverence even today. The ambience of his kingdom was conducive to the creation of high quality work of art and literature. These accomplishments were the outcome of a longstanding tradition sustained by several generations. 3. The life of the people of Mewar must have been peaceful and prosperous during the long span of time; otherwise such extraordinary accomplishment in these fields would not have been possible. This is reflected in their art and literature as well as their loving nature. They compensate for lack of admirable physique by their firm but pleasant nature. The ambience of Mewar remains lovely thanks to the cheerful and liberal character of its people. 4. One may observe astonishing pieces of workmanship not only in the forts and palaces of Mewar but also in public utility buildings. Ruins of many structures which are still standing tall in their grandeur are testimony to the fact that Mewar was not only the land of the brave but also a seat of art and culture. Amidst aggression and bloodshed, literature and art flourished and creative pursuits of literature and artists did not suffer. Imagine, how glorious the period must have been when the Vijaya Stambha which is the sample of our great ancient architecture even today, was constructed. In the same fort, Kirti Stambha is standing high, reflecting how liberal the then administration was which allowed people from other communities and kingdoms to come and carry out construction work. It is useless to indulge in the debate whether the Vijaya Stambha was constructed first or the Kirti Stambha. The fact is that both the

capitals are standing side by side and reveal the proximity between the king and the subjects of Mewar. 5. The cycle of time does not remain the same. Whereas the reign of Rana Sanga was crucial in raising the kingdom to the acme of glory, it also proved to be his nemesis. History took a turn. The fortune of Mewar – the land of the brave, started waning. Rana tried to save the day with his acumen which was running against the stream and the glorious traditions for sometime. On the basis of your understanding of the above passage answer each of the questions given below with the help of options that follow : (1 × 4 = 4) (a) Maharana Pratap became immortal because : (i) he ruled Mewar for 25 years. (ii) he added a lot of grandeur to Mewar. (iii) of his valour, sacrifice and patriotism. (iv) both (ii) and (iii) (b) Difficulties in the way of Mewar were : (i) lack of cooperation of the nobility. (ii) ancient traditions of the kingdom. (iii) its small area and small population. (iv) the poverty of the subjects. (c) During thorny occasions : (i) the flag of Mewar seemed to be lowered. (ii) the flag of Mewar was hoisted high. (iii) the people of Mewar showed gallantry. (iv) most of the rulers heaved a sigh of relief. (d) Mewar was lucky because : (i) all of its rulers were competent. (ii) most of its people were competent. (iii) most of its rulers were competent. (iv) only a few of its people were incompetent. Answer the following questions briefly : (1 × 6 = 6) (e) Who is the earliest king of Mewar mentioned in the passage ? (f) What was Rana Kumbha’s contribution to the glory of Mewar ? (g) What does the writer find worth admiration in the people of Mewar ? (h) How could art and literature flourish in Mewar ? (i) How did the rulers show that they cared for their subjects ? (j) What does the erection of Vijaya Stambha and Kirti Stambha in the same fort signify ? (k) Find words from the passage which mean the same as each of the following : (1 × 2 = 2) (i) surprising (para 4) (ii) evidence (para 4)

SUMMER VACATION HOLIDAYS HOMEWORK

CHEMISTRY

1. 50 numericals from chapter 1 to chapter 4.

2. Complete CW and HW up to chapter 4.

3. Prepare investigatory project for CBSE practical examinations (take help

from icbse.com).

4. Solve CBSE questions from chapter 1 to 4 (2012 – 2017) in your HW

notebook.

5. Learn chapters from 1 to 4.

6. Prepare notes and learn – Biomolecules, Polymers and Chemistry in

everyday life.

7. Complete Practical notebook:

To prepare colloidal solution of ferric hydroxide and starch. To prepare

colloidal solution of egg albumin To identify – Carbonates, sulphite,

sulphide, nitrite, acetate. Chloride, bromide, iodide, sulphate, nitrate.

HOLIDAY HOMEWRK

CLASS –XII

SUBJECT-BIOLOGY

A-Draw diagram of chapter -2 and chapter -3

1. T.S. of microsporangium

2. Development of pollen grain

3. A typical anatropous ovule

4. Development of embryo sac

5. Development of dicot embryo

6. L.S. of embryo of grass

7. Sectional view of seminiferous tubule

8. Structure of a sperm

9. Section view of ovary

10. Ovum

11. Transport of zygote upto implantation

B- Prepration of investigatory project

C- Solve the following questions

a. Explain the significance of meiocytes in a diploid organism.

b. Why is breast-feeding recommended during the initial period of an infant’s growth ? Give reasons

Reproductive and Child Healthcare (RCH) programmes are currently in operation. One of the major tasks of

these programmes is to create awareness amongst people about the wide range of reproduction related

aspects. As this is important and essential for building a reproductively healthy society.

(a) “Providing sex education in schools is one of the ways to meet this goal.” Give four points in support of

your opinion regarding this statement.

(b) List any two ‘indicators’ that indicate a reproductively healthy society.

c. (a) Explain the post-pollination events leading to seed production in angiosperms.

(b) List the different types of pollination depending upon the source of pollen grain.

d. (a) Briefly explain the events of fertilization and implantation in an adult human female.

(b) Comment on the role of placenta as an endocrine gland.

E. explain the importance of syngamy and meiosis in a sexual life cycle of an or

KV NO.2 DELHI CANTT (II SHIFT)

SUMMER HOLIDAYS HOMEWORK 2017-18

BUSINESS STUDIES CLASS XII

1. Revise chapter 1 ,2, 3.

2. Practice case studies of chapter 1,2,3.

3. Do project work as explained in class.

ACCOUNTANCY CLASS XII

1. Comprehensive problem project in proper format for CBSE practical 2. Do the additional questions of DR D. K Goel of following chapters (A) fundamentals of partnership

(B ) goodwill nature & valuation ( C) change in PSR ( D ) admission of partner ( till treatment of goodwill)

HISTORY

CLASS 12

1. Make PPT of all Five Chapters.

2. Make a Project on any one topic (pictures, important factors, maps etc.

POLITICAL SCIENCE

1. Read newspaper daily and collect information related to your subject. Write

your comment on it.

2. Make minimum 25 questions of one word or one sentence from Political

Science book- Politics in India since Independence of first three chapters.

3. Learn and revise all the chapters which were taught in the class.

GEOGRAPHY

1. Explain possibilism with example.

2. Explain neo- determinism.

3. How does Science and technology has affected human population.

4. Mention 6 fields of human Geography.

5. What are the two components of population growth in India? Describe its

main features.

6. The year 1951 to 1981 is reffered to as Population explosion period. Explain.

7. Explain Five factors that affect population distribution in India.

8. Define migration. Explain its four factors.

9. Explain the four streams of migration in India.

10. Explain any four push factors.

11. Explain the economic and social consequences of migration.

12. Explain demographic transition theory with diagram.

13. Define density of population.

14. What are the factors influencing world population.

15. Explain age structure of population. Describe its four characteristics.

16. Explain occupational structure with diagram.

17. Practice all the maps of India and world.

Holiday Homework

Class XII-CS

Classes & Objects (HOTS Questions)

Q1. Define a class Departmental with the following specification :

private data members Prod_name string (45 charactes) [ Product name]

Listprice long Dis_Price long [ Discount Price]

Net long [Net Price ]

Dis_type char(F or N) [ Discount type] Cal_price() – The store gives a 10% discount on every product it sells. However at the

time of festival season the store gives 7% festival discount after 10% regular discount. The

discount type can be checked by tracking the discount type. Where „F‟ means festival and „N‟ means Non- festival .The Cal_price() will calculate the Discount Price and Net Price on the basis

of the following table.

public members Constructor to initialize the string elements with “NULL”, numeric elements with 0

and character elements with „N‟

Accept() - Ask the store manager to enter Product name, list Price and discount type . The function will invoke Cal_price() to calculate Discount Price and Net Price .

ShowBill() - To generate the bill to the customer with all the details of his/her purchase along with the bill amount including discount price and net price.

Q2. Define a class TAXPAYER in C++ with following description :

Private members :

a. Name of type string b. PanNo of type string

Product Name List Price(Rs.)

Washing Machine 12000

Colour Television 17000

Refrigerator 18000

OTG 8000

CD Player 4500

c. Taxabincm (Taxable income) of type float d. TotTax of type double e. A function CompTax( ) to calculate tax according to the following slab: Taxable Income Tax%

Up to 160000 0

>160000 and 300000 and 500000 15

Public members :

A function to input data members. A function INTAX( ) to enter data for the tax payer and call function CompTax( ) to

assign TotTax.

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

Q3. Define a class RESORT with the following specifications.

Private members: Data members : roomno- int, name- string, charges- float, days- int, amount- float. Member function: compute( ) - To calculate and return amount as days * charges

and if the value of days * charges is more than 2100 then as 1.5 * days * charges.

Public members:

Member Functions: enterdetails ( )– to input data and invoke compute( ) function.

display ( ) – to display the details of the customer

Q4. Define a class T20 in C++ with the following specifications

Private members : Target_runs of type integer

Overs of type integer

Extra_time of type integer

Penalty_runs of type integer CALPENALTY( ) a member function to calculate penalty runs as follows :

If Extra_time10 and ='F' && Text[K]

Text[K]=toupper(Text[K]);

else

Text[K]=Text[K-1];

}

}

void main( ) {

char oldText[ ]= "Click@CAreeR2013" ;

ChangeIt (oldText,'%');

cout

void main()

{

Metro M(5),T;

M.Trip();

T.Trip(50);

M.StatusShow();

M.Trip(30);

T.StatusShow();

M.StatusShow();

}

3 Find the output of the following program:

#include

#include

#include

typedef char Str80[80];

void main()

{

clrscr();

char *Notes;

Str80 Str="vR2GooD";

int L=6;

Notes=Str;

while(L>=3)

{

Str[L]=(isupper(Str[L])?tolower(Str[L]):toupper(Str[L])) ;

cout

4 . Observe the following program and find out, which output(s) out of (i) to (iv) will not be expected from the program? What will be the minimum and the maximum value assigned to the variable Chance?

#include

#include void main( ) { randomize( ); int Arr[ ]={9,6},N; int Chance=random(2)+10; for(int I=0; I

{ int year; public: Exam(int y) {year=y;} //Constructor 1 Exam(Exam & t); ///Constructor 2 };

i) Create an object, such that it invokes Constructor I. (1) ii) Write complete definition for Constructor 2. (1)

3. Answer the questions (I) and (ii) after going through the following class:

class Student { int adm; public: Exam(int a) {adm=y;} //Constructor 1 Student (Student & t); ///Constructor 2 }; i) Create an object, such that it invokes Constructor I. (1) ii) Write complete definition for Constructor 2. (1)

4. Answer the questions (I) and (ii) after going through the following class:

class Demo { int A; public: Demo () //Function 1 { } Demo (int D) //Function 2 { A=D; } Demo (Demo &M) //Function 3 { A=M.A; } };

i) Which category of constructor - Function 3 belongs to and what is the purpose of using it? ii) Write statements that would call the member Functions 1 and 2

5. What is/are the uses of constructor and destructors in C++? 6. Answer the questions (I) and (ii) after going through the following class:

class Ex { int yr; public: Ex(int y) {yr=y;} //statement 1 Ex(Ex & t); // statement 2 };

i) Create an object, such that it invokes Constructor I. (1) ii) What is the concept implemented by statement 1 and statement 2 . (1)

PHYSICS

Electric Force and Field: 1. Draw a plot showing the variation of

i. Electric field and ii. Electric potential with distance ‘r’ due to a point charge Q. (Delhi

2012) 2. Plot a graph showing the variation of Coulomb’s force ‘F’ versus 1/r2, where r is

the distance between the two charges of each pair of charges: (1µC, 2µC) and (1µC, -3µC). Interpret the graphs obtained. (All India 2011C)

3. Deduce the expression for the electric field E

due to a system of two charges q1

and q2 with position vectors 1r

and 2r

at a point at r

with respect to common

origin. (Delhi 2010C)

Gauss’ Law: 4. Draw the shapes of suitable Gaussian surfaces, while applying Gauss’ law to

calculate the electric field due to- i. A uniformly charged long straight wire.

ii. A uniformly charged infinite plane sheet. (Delhi 2009C)

5. Define electric flux. Write its SI unit. A spherical rubber balloon carries a charge q that is uniformly distributed over its surface. As the balloon is blown up and increases in size, how does the total electric flux coming out of the surface of the balloon change? Give reason. (Delhi 2007)

Electric potential: 6. Draw an equipotential surface for a system of two similar and opposite charges. 7. Two charged conducting spheres of radii r1 and r2 connected to each other by a

wire. Find the ratio of the electric fields at the surfaces of the two spheres. (Delhi 2011C)

8. Define the dipole moment of an electric dipole. How does the electric potential of an electric dipole vary on the dipole axis as a function of distance ‘r’ of the point from the midpoint of the dipole at large distances? (AI 2008C)

Potential Energy and Work done: 9. A fully charged capacitor is disconnected from the battery and the plates are

pulled apart. What will happen to the potential energy of the capacitor? If there is any increase in energy, explain the source of additional energy.

Electric capacitance:

10. What is the function of a dielectric slab in an electric capacitor? 11. Define the dielectric constant of a medium. Briefly explain why the capacitance

of a parallel plate capacitor increases on inserting a dielectric slab in between the plates?

CONCEPTUAL QUESTIONS: 12. The emf of a cell is greater than its terminal voltage. Give reason.

13. Two wires of equal length, one of copper and the other of manganin have the same

resistance. Which wire is thicker? 14. In an experiment on Meter Bridge, the balancing length AC is X. What would be its

value, when the radius of the meter bridge wire is doubled? Justify your answer.

Current and Drift Velocity:

15. Show on a graph, the variation of resistivity of a typical semiconductor with temperature.

16. A conductor of length l is connected to a potential difference V. of the length of the conductor is tripled, by gradually stretching it, keeping V constant, how will-

a. Drift speed of the electrons will change? b. Resistance of the conductor will be affected?

17. Derive an expression for drift velocity of electrons in terms of relaxation time of electrons.

18. Derive an expression for the resistivity of a good conductor, in terms of relaxation time of electrons.

19. Derive an expression for the current density of a conductor in terms of drift velocity of electrons.

20. Write the mathematical relation for the resistivity of a material in terms of relaxation time, number density, mass and charge on the charge carriers in it. Explain using the relation, why the resistivity of a material increases and that of a semiconductor decreases with rise in temperature.

Resistance and Ohm’s law:

21. The three coloured bands on a carbon resistor are red, green and yellow respectively. Write the value of the resistance.

22. Write an expression for the resistivity of a conductor showing its variation over a limited range of temperature.

Emf and Internal Resistance:

23. The emf of a cell is always greater than the terminal voltage. Why? Give reason. 24. A resistance R is connected across a cell of emf E and internal resistance r. Now a

potentiometer measures the potential difference between the terminals of the cells as V. Write the expression for ‘r’ in terms of E, V and R.

25. A cell of emf and internal resistance r is connected across a variable resistor R. plot a graph showing the variation of terminal voltage V with R.

26. Plot a graph showing the variation of terminal potential difference V across a cell of emf

and internal resistance r with current drawn from it. Using the graph show how emf of the cell can be determined?

Combination of cells:

27. Two identical cells each of emf E, having negligible internal resistance are connected in parallel with each other across an external resistance R. what is the current through this resistance? Ans: E/R

28. Two cells of emf 2 and and internal resistance 2r and r are connected in parallel. Obtain the expressions for equivalent emf and internal resistance.

29. A number of identical cells ‘n’, each of emf , internal resistance r are connected in

series are charged by a battery of emf ‘o’ using a resistor. a. Draw the circuit arrangement. b. Deduce the expressions for

i. The charging current and ii. The potential difference across the combination of the cells.

Meter Bridge:

30. In the meter bridge experiment, balance point was observed at J with AJ=l. a. The values of R and X were doubled and then interchanged. What would be

the new position of balance point? b. If the galvanometer and battery are interchanged at the balance position,

how will the balance point get affected? 31. Obtain the balance condition for Wheatstone bridge using Kirchhoff’s laws.

Potentiometer:

32. The variation of potential difference with length in case of two potentiometers A and B is shown in the figure. Which of these two will you prefer for comparing the emfs of two primary cells?

33. A series and parallel combination of two resistors is connected, one by one, across a cell. In which case will the terminal voltage, across the cell, have a higher value?

34. For the potentiometer circuit shown in the figure, X and Y represent two terminals of a

cell of unknown emf . A student observed that when the jockey is moved from the end A to the end B of the potentiometer wire, the deflection in the galvanometer remains in the same direction. What may be the two possible faults in the circuit that may result in this observation? If the galvanometer deflection at the end B is (a) more, (b) less, than at the end A, which of the two faults , listed above, would be there in the circuit? Give reason in support of your answer in each case.

ASSIGNMENT

35. A wire of resistance R is stretched to double its length. What will be its

resistance and resistivity?

36. Compare the resistance of two wires of same material. Their lengths are in the

ratio 2:3 and their diameters are in the ratio 1:2.

Ans: R1: R2=8:3

37. With two resistances R1 and R2 in the two gaps of a meter bridge, the null point

is obtained at 1/3m from the zero end. When a resistance of 6 is connected in

series to the smaller of the resistances, the null point is shifted to 2/3 m form

the same end. Calculate R1 and R2.

Ans: R1=2 and R2=4

38. What’s the effective resistance of the following circuits?

Ans: R, R/2, 4

39. AB is a potentiometer wire. If the value of resistance R in the driving circuit is increased, in which direction will the balance point J shift?

40. An electron of hydrogen atom is revolving around the nucleus in the circular

orbit of radius 2

2 24

h

me with velocity

22 e

h

. What is the equivalent current in the

atom? Ans 5

3

4 me

h

41. A hollow cylinder of length l and radius a and b is filled with

a material of resistivity and is connected to a battery of emf

through an ammeter, as shown in the figure. Find the

current through the ammeter. Ans

2

loge

E l

ba

42. Why potentiometer is preferred over voltmeter for measuring emf? 43. Manganin is used for standard resistors. Why? 44. A conductor of length l is connected to a DC source of potential V. if the length

of the conductor is tripled by stretching it. Keeping V constant, explain how do the following factors vary in the conductor: a. Drift speed of the electrons b. Resistance and resistivity.

45. A current is passed through a cylindrical conductor of gradually decreasing radius. At which point the drift speed of the electrons will be higher?

46. Two wires of same dimension but resistivity 1 and 2 are connected in series and than in parallel. Find out the equivalent resistivity for each case.

47. Current is allowed to flow through a metallic wire at a constant potential difference. When the wire becomes hot, cold water is poured on half portion of it. By doing so, the other portion becomes hotter. Explain.

48. A battery is first connected across a resistor R1 and then to R2. Find the value of internal resistance r of the battery for which the heat released in external circuit be same in both the cases.

Ans: 1 2

R R

49. A cell supplies current i1 through a coil of resistance R1 and a current i2 through another coil of resistance R2. What is the emf and internal resistance of the cell? Ans:

2 2 1 1

1 2

i R i Rr

i i

1 2 2 1

1 2

i i R RE

i i

50. Two cells each of equal emf but of internal resistance r1 and r2 are connected in series through an external resistance R. Find the value of R in terms of r1 and r2 for which first cell will have zero potential difference across it.

Ans: 2 1

r r