CLASS XII HOLIDAY HOME WORK MATHS

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CLASS XII HOLIDAY HOME WORK MATHS

HOLIDAY HOME WORK

SUB: BIOLOGY FOR CLASS XII

Chapter 1 REPRODUCTION IN ORGANISMS

1 Name the phase all organisms have to pass through before they can reproduce

sexually.

1

2 Mention the site where syngamy occurs in amphibians and reptiles respectively.

1

3 Name an organism where cell division itself is a mode of reproduction? 2013

1

4 Name an alga that reproduces asexually through zoospores. Why are these

reproductive units so called?

1

1

5 Name an organism where cell division itself is a mode of reproduction?

1

6 Name the phenomenon and one bird where the female gamete directly develops

into a new organism?

1

7 Name the vegetative propagules in the following(2014)

a) Agave

b) Bryophyllum

1

8 Why do moss plants produce very large number of male gametes? Provide one reason. What are these gametes called?(2015)

2

9 A liverwort plant is unable to complete its life- cycle in a dry environment. State two reasons.

2

Chap 2 SEXUAL REPRODUCTION IN FLOWERING PLANTS

1 How do the pollen grains of vallisneria protect themselves?

1

2 Name the type of flower which favours cross pollination.

1

3 Why is bagging of the emasculated flower essential during hybridization

experiments?

1

4 Pea flowers produce assured seed sets. Give a reason.

1

5 Why banana is considered a good example of parthenocarphy?

1

6 Name the part of the flower which the tassels of the corn –cob represent.(2014)

1

7 Give an example of a plant which came into India as a contaminant and is a cause

of pollen allergy.

1

8 State one advantage and one disadvantage of cleiostogamy.

2

9 In angiosperms, zygote is diploid while primary endosperm cell is triploid.

Explain?(2013)

2

10 Name all the haploid cells present in an unfertilized mature embryo – sac of

flowering plant. Write the total number of cells in it? 2013

2

11 Explain the function of each of the following

a) coleorhizae –b)germ pores –

2

12 Draw a vertical section of a maize grain and label i)

pericarp,ii)scutellum,iii)coleoptiles and iv) radical

Ans:

Or

Mention any two uses of seeds.

2

13 State what is apomixis? Comment on its significance. How can it be commercially used? (2015)

2

14 Differentiate between perisperm and endosperm giving one example each.

3

15 Fertilization is essential for production of seed, but in some angiosperms seeds

develop without fertilization.

i) Give an example of angiosperm that produces seeds without

fertilization.name the process.

ii) Explain two ways by which seeds develop without fertilization.

3

16 a) Mention any four strategies adopted by flowering plants to prevent self

pollination.

b) Why is geitonogamy also referred to as genetical autogamy?

3

17 Make a list of any three out breeding devices that flowering plants have developed

and explain how they help to encourage cross – pollination. (2014)

OR

Why are angiosperm anthers called dithecous? Describe the structure of its

microsporangium. (2014)

3

18 Why are some seeds referred to as apomictic seeds? Mention one advantage and one disadvantage to a farmer who uses them.(2015)

3

19 a)Why is fertilization in angiosperm referred to as double fertilization? Mention

the ploidy of the cell involved.

b) Draw a neatly labeled sketch of L.S of an endospermous monocot seed.

5

Any four labels including endosperm =2

20 a) Trace the development of embryo after syngamy in a dicot plant.

b) Endosperm development precedes embryo development. Explain

c) Draw a diagram of a mature dicot embryo and label cotyledons, plumule,

radical and hypocotyls in it.

explanation of the figure / above diagram can be considered//

5

21 Give reasons why:1x5=5 marks

i) Most zygotes in angiosperms divide only after certain amount of endosperm is

formed.

ii)groundnut seeds are exalbuminous and castor seeds are albuminous

iii)micropyle remains as a small pore in the seed coat of a seed

iv) Integuments of an ovule harden and the water content is highly reduced, as the

seed matures.

v) Apple and cashew are not called true fruits.

c) Give reason for each of the following

i

i)

5

22 How does the pollen mother cell develop into a mature pollen grain? Illustrate the

stages with labeled diagrams.

1/2x5=2 1/2

5

23 a) Trace the development of megaspore mother cell up to the formation of a

mature embryo-sac in flowering plant

b) draw a labeled diagram of the structure of mature dicot embryo

5

24 Draw a L.S of a pistil showing pollen tube entering the embryo-sac in an

angiosperm and label any six other than stigma, style and ovary.

(b) Write the changes a fertilized ovule undergoes within the ovary in an

angiosperm plant.

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25 A) Describe the endosperm development in coconut.

B) Why is tender coconut considered a healthy source of nutrition?

C) How are pea seeds different from castor seeds with respect to endosperm?

5

26 a) Explain the different ways apomictic seeds can develop. Give an example of

each.

b) Mention one advantage of apomictic seeds to farmers.

c) Draw a labeled mature stage of a dicotyledonous embryo. (2014)

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27 a) Plan an experiment to and prepare a flow chart of the steps that you would follow to ensure that the seeds are formed only from the desired sets of pollen grains. Name the type of experiment that you carried out. b) Write the importance of such experiments.(2015)

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CHAP-3 HUMAN REPRODUCTION

1 Where are the leydig cells present?what is their role in reproduction? 1

2 Name the embryonic stage that gets implanted in the uterine wall of a human

female.

1

3 How is the entry of only one sperm and not many ensured into an ovum during

fertilization in humans?

1

4 Where is acrosome present in human? Write its function. 1

5 What stimulates pituitary to release the hormone responsible for parturition?

Name the hormone.

1

6 Explain the functions of umbilical cord. 1

7 Give reasons for the following

a) The human testes are located outside the abdominal cavity.

b)some organisms like honey-bees are called parthenogenetic animals

2

8 a) Where do the signals for parturition originate from the humans?

b) Why is it important to feed the newborn babies on colostrums?

2

9 Differentiate between major structural changes in human ovary during the

follicular and luteal phase of the menstrual cycle.

2

10 Why are humans testes located outside the abdominal cavity? Name the pouch in

which they are present? (2014)

2

11 Write the location and functions of the following in human testes :

(a) Sertoli cells

(b) Ledig cells (2014)

2

12 Write the effect of high concentration of LH on a mature graafian follicle.(2014)

Rupture of graafian follicle, release of ovum/secondary oocytes/ovulation. = 1+1

2

13 Draw a labeled diagram of the reproductive system in a human female. 3

14 Explain the steps in the formation of an ovum from an oogonium in humans. 3

15 a) When and how does placenta develop in human female?

b) How is the placenta connected to the embryo?

c) Placenta acts as an endocrine gland. Explain.

5

16 The following is the illustration of ovarian events ‘a’ to ‘I’in a human female

a) Identify the figure that illustrates corpus luteum and name the pituitary

hormone that influences its formation.

b) Specify the endocrine function of corpus luteum. How does it influence the

uterus? Why is it essential?

c) What is the difference between “d” and “e”?

d) Draw a neat labeled sketch of graffian follicle.

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17 Study the flow chart given below. Name the hormones involved at each stage and

explain their functions.

Hypothalamus

Pituitary

Ovary

Pregnancy

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8.

9

10.

18 Draw a diagrammatic sectional view of a human seminiferous tubule, and label

sertoli cells, primary spermatocyte, spermatogonium and spermatozoa in it.

a) Explain the hormonal regulation of the process of spermatogenesis in

human.

5

19 a) Draw a diagrammatic labeled sectional view of a seminiferous tubule of a

human.

b) Describe in sequence the process of spermatogenesis in humans.

5

20 Describe the post zygotic events leading to implantation and placenta formation in

humans. Mention any two functions of placenta.

5

21 (a) Where does fertilization occur in humans? Explain the events that occur during

this process. (2014)

(b A couple where both husband and wife are producing functional gametes, but

the wife is still unable to conceive, is seeking medical aid. Describe any one

method that you can suggest to this couple to become happy parents. (chap -4)

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CHEMISTRY

SOLID STATE CLASSXII

1. How may the conductivity of an intrinsic semiconductor be increased ? (CBSE 2012)

2. Which stoichiometric defect increases the density of a solid ? (CBSE 2012, 11)

3. What are n-type semiconductors ? (CBSE 2012)

4.. What type of semiconductor is obtained when Si is doped with As ? (CBSE 2010)

5. Which point defect decreases the density of a solid ? (CBSE 2010, 09,2008)

.6. What is the No. of atoms in a unit cell of fcc crystal ? (CBSE 2009,13)

7. Define forbidden zone of an insulator ? (CBSE 2008)

8. What is the No. of atoms in a unit cell of simple cubic crystal ? (CBSE 2010)

.9. State a feature to distinguish a metallic solid from an ionic solid . (CBSE 2010)

10. “Crystalline solids are anisotropic in nature .” What does this statement mean ? (CBSE 2011)

11. Which point in crystal does not change the density of a solid ? (CBSE 2010,09)

12. What type of interaction hold the molecule together in a polar molecule ? (CBSE 2010)

.13. Wrire a distinguishing feature of metallic solid . (CBSE 2010)

14. What is meant by intrinsic semiconductor ? (CBSE 2011)

15. What is the No. of atoms in a unit cell of bcc crystal ? (CBSE 2011)

16. Why LiCl acquire pink colour when heated in Li vapour ? (CBSE sample 2011)

17. What type of substance would make better permanent magnets, ferromagnetic or ferromagnetic?

(2013)

18. Silver crystallises in fcc structure . Each side of the unit cell has a length of 409 pm .What is the

radius of Ag atom? (CBSE 2011,10,09)

19. Calculate the packing efficiency of a metal crystal for simple cubic lattice. (CBSE 2011)

20.Explain how you can determine the atomic mass of an unknown solid if u know the mass density and

the dimensions of unit of its crystal. (CBSE 2011)

21.Define the following terms w.r.t. crystalline solid – (a) Unit cell (b) Coordination No.

Give example in each case.

22.KF has ccp structure. Calculate the radius of unit cell if the side of the cube is 400 pm. How many

F – ions & Octrahedral voids are there in this unit cell. (CBSE sample 2011)

23 Give reason – (CBSE sample 2011)

(a) Why is Frankel defect found in AgCl ?

(b) What is difference between phosphorus doped & gallium doped semiconductors. ?

24.Gold (Atomic mass = 197 u, Atomic radius = 0.144 nm) crystallises in a fcc unit cell.

Determine the density of Gold. (CBSE sample 2011)

25.. Classify each of the following as being either a p- type or a n-type semiconductor. Give reason.

(a) Si doped with In (b) Si doped with P. (CBSE sample 2011)

26. Account for the following:- (CBSE 2013)

a) Schottky defect lowers the density of related solids.

b) Conductivity of Silicon increases on doping it with Phosphorus.

27..(a)Why does presence of excess of lithium makes LiCl crystals pink?

(b) A solid with cubic crystal is made of two elements P and Q. Atoms of Q are at the corners of the

cube and P at the body center. What is the formula of the compound ? (CBSE 2013)

28. (a) What type of non- stoichometric point defect is responsible for the pink color of LiCl?

(b) What type of stoichiometric defect is shown by NaCl? (CBSE 2014)

29.How will you distinguish between the following pairs of terms: (CBSE 2014)

(a) Tetrahedral and octahedral voids (b)crystal lattice and unit cell

30. ( a) Write the type of magnetism observed when the magnetic moments are oppositely aligned and

cancel out each other.

(b) Which stoichiometric defect does not change the density of the crystal ? (CBSE 2014)

31 (a) Write the type of magnetism observed when the magnetic moments are aligned in parallel and anti-

parallel directions in unequal numbers .

(b) Which stoichiometric defect decreases the density of the crystal? (CBSE 2014)

32. Copper crystallises with fcc unit cell . if the radius of Copper atom is 127.8 pm , calculate the density

of copper metal . (Atomic Mass of Cu = 63.55 & Avagadro No. = 6.02x 1023

mol-1

) (2012, 10)

33.Iron has a bcc unit cell with the cell dimension of 286.65 pm . Density of iron is 7.87 g/cc . use this

information to calculate & Avagadro’s No. (At. Mass of Fe = 56) . (CBSE 2012)

34.The density of copper metal is 8.95 g/cc, if the radius of Cu atom is 127.8 pm , is the Cu unit cell

simple Cubic, bcc or fcc ? (CBSE 2012, 10)

35. Silver crystallises in fcc structure if the edge length of the unit cell is 4.07 x 10-8

cm & density of the

crystal is 10.5 g/cc , calculate the atomic mass of Silver. (CBSE 2010, 09)

36.Niobium (Nb) crystallises in bcc structure . If its density is 8.55 g/cc, calculate the atomic radius of

Nb. (atomic mass of Nb = 93 u) (CBSE 2008)

37.The well known mineral fluorite is chemically calcium fluoride . It is known that in one unit cell of

this mineral there are 4 Ca2+

ions and 8F ─

ions and that Ca2+

ions are arranged in fcc lattice . The F ─

ions fill all the tetrahedral holes in the fcc lattice of Ca2+

ions The edge of unit cell is 5.46 x 10 -8

cm in length the density of solid is 3.18 g/cc. Use this information to calculate the Avagadro’s

number . (Molar mass of CaF2 = 78.08 g/mol) (CBSE 2010)

38.Aluminium crystallises in a cubic close-packed structure. Radius of the atom in the metal is 125 pm .

(i) What is the length of the side of the unit cell ?

(ii) How many unit cells are present in 1 cm3 of Aluminium ? (CBSE 2011,13)

39.Sodium crystallises in a bcc unit cell .calculate the approximate No. of unit cells in 9.2 g of Sodium.

40. (a) What type of semi conductor is obtained when silicon is doped with boron? (CBSE 2013)

(b) What type of magnetism is shown in the following alignment of magnetic moments?

↑↑↑↑

(c) What type of point defect is produced when AgCl is doped with CdCl2?

41.An element with density 2.8 g cm-3

forms a fcc unit cell with edge length 4x10-8

cm. calculate the

molar mass of the element. (CBSE 2014)

HOTS QUESTIONS

1. When a crystal of NaCl is heated in sodium vapour, it acquires a yellow colour. The yellow colour is due

to non stoichiometric defect. Name the defect.

2. In the face centered cubic arrangement of A and B atoms where A atoms are at the corner of the unit

cell and B atoms at the face centres. One of the A atom is missing from one corner in the unit cell.

What is the simplest formula of the compound?

3. In Chromium(III) Chloride, CrCl3, chloride ions have cubic close packed arrangement and Cr(III) ions are

present in the octahedral holes. What is the fraction of octahedral holes occupied? What is the fraction

of total number of holes occupied?

4. The composition of a sample of wustite is Fe0.93O1.00. What percentage of Fe is present as Fe(III)?

5. Calcium crystallizes in a face centred cubic unit cell with a=0.556nm. Calculate the density if

i. It contains 0.1% Frenkel defects.

ii. It contains 0.1% Schottky defects.

Hint:

Frenkel defect does not affect density.

d=zM/a3NA

Schottky defect reduces the density by 0.1%, assuming that volume remains constant.

d’=d( 1- 0.1/100) ; d’=0.999d

6. The concentration of cation vacancies in NaCl crystal doped with CdCl2 is found to be 6.02x1016

mol-1

.

What is the concentration of CdCl2 added to it?

7. Iron changes its crystal structure from body centred to cubic close packed structure when heated to

916°C. Calculate the ratio of the density of the BCC crystal to that of CCP crystal. Assume that the

metallic radius of the atom does not change. Hint: Volume same, so ratio of density is also same i.e.

d(bcc)/d(ccp)

VALUE BASED QUESTION

1. Chetan asked his father, ‘’ How should a relationship be ? ‘’ His father gave him a piece of solid Iron

and said that the relationship should be like this. After reading this passage, answer the following

questions.

(i) Why do solids have a definite shape and a definite volume ?

(ii) Mention the values associated with the above conversion.

2. Solids have fixed shape and volume but experimentally it has been observed that solids are also

defective. Two types of defects are found in solids, namely, point defect and line defect. After

reading the above passage, answer the following questions-

(i) What type of defect can arise when a solid is heated ?

(ii) How many types of point defects are there ?

(iii) Mention the values associated with the above information.

One of the given investigatory projects-

Study of the presence of oxalate ions in guava fruit at different stages of ripening.

Study of quantity of casein present in different samples of milk.

Preparation of soybean milk and its comparison with the natural milk with respect to curd formation,

effect of

temperature, etc.

Study of the effect of Potassium Bisulphate as food preservative under various conditions (temperature,

concentration, time, etc.)

Study of digestion of starch by salivary amylase and effect of pH and temperature on it.

Comparative study of the rate of fermentation of following materials: wheat flour, gram flour, potato

juice,

carrot juice, etc.

Extraction of essential oils present in Saunf (aniseed), Ajwain (carum), Illaichi (cardamom).

Study of common food adulterants in fat, oil, butter, sugar, turmeric power, chilli powder and pepper.

Any other project from the sites

1) icbse .com 2) 1000 projects in chemistry

kond`Iya ivaValaya ko ir pu bala AavaD,I caonna[-. Class : xii A and B

Subject : Hindi

Holiday Home Work

Summer Vacation-2016-17

1) caar p~ laoKna : dao AaOpcaairk p~ dao AnaaOpcaairk p~ 2) inabanQa : k) praopkar K) kmPyaUTr Aaja kI AavaXyakta. ga) [nTrnaoT Gar-Aa^Mgana. Ga) naarI AaOr naaOkrI. =) baZ,tI mah^Mgaa[--samasyaa AaOr samaaQaana.

3) ek AalaoK : jaao kxaa maoM ilaKayaa gayaa hO. 4) saMcaar maaQyama sao kao[- baIsa p`Xnaao<ar.

XauBakamanaae^M

POLITICAL SCIENCE

1)ppt on challenge to bipolarity.

2)NIEO

3)LDCS

4)NAM

5)DISINTERGRATION OF USSR

6)CONSEQUENCES OF DISINTERGRATION

HISTORY

1)sources of mauryan empire

2) mauryan administration

3)how are inscripition deciphered

GEOGRAPHY

1)collect information about elnino & lanina

PHYSICS

Class :XII

Physics

QUESTION BANK

CHAPTER – 1:– FORCE

SUBMISSION DATE: -21/6/2015

1) How many ‘e’s’ make up one coulomb of negative charge?

2) What is the cause of charging?

3) What is the basic cause of quantization of charge?

4) Force of attraction between two point charges placed at a distance of ‘d’ is ‘F’. What distance apart

they are kept in the same medium, so that, the force between them is ‘F/3’?

5) What is meant by quantization of charge and conservation of charge?

6) How far apart two protons are if the electronic force exerted by one on the other is equal to weight

of the electron?

7) Force between two point electric charges kept at a distance‘d’ apart in air is ‘F’. If these charges are

kept at the same distance in water, how does the force between them change?

8) What is the electric constant of a metal

9) Name the experiment which established quantum nature of electric charge.

10) How is the force between two charges affected when dielectric constant of the medium in which they

are placed increases?

11) What does q1+q2 = 0 signify in electrostatics?

12) State two basic properties of electric charge?

13)

14) 15. Two

equal balls with equal positive charge 'q' coulombs are suspended by two insulating strings of equal length.

What would be the effect on the force when a plastic sheet is inserted between the two?

CHAPTER – 2:– ELECTRIC FIELD

1. Draw lines of force to represent a uniform electric field

2. Four charges of same magnitude and same sign are placed at the corners of a square of each side

0.1m. What is the electric field intensity at the centre of the square?

3. Force experienced by an electron in an electric field is ‘F’ Newton. What will be the force experienced

by a Proton in the same field?

4. Name the physical quantity where SI unit is NC-1

.

5. Is electric field intensity a scalar or a vector quantity? Give its SI unit.

6. Define electric dipole moment. Is it a scalar or a vector quantity?

7. Sketch the electric value of force due to point charges q > 0, q < 0

8. Derive an expression for electric field intensity at a point on the axial line of an electric pole.

9. The distance of the field point on the equatorial plane of a small electric dipole is halved. By what

factor will the electric field due to the dipole charge?

10. When will an electric dipole remains stable equilibrium in an electric filed?

11. Derive an expression for torque acting on an electric dipole in a uniform electric filed.

12. Derive an expression for total work done in rotating an electric dipole through an angle ‘θ’ in uniform

electric field

13. Why two lines of force never intersect each other?

14. In which orientation a dipole placed in a uniform electric field is in a)stable and b)unstable

equilibrium

15. CHAPTER – 3:– ELECTROSTATIC POTENTIAL & GAUSS’s THEOREM

1. A sphere ‘S1’ of radius ‘r1’ encloses a charge ‘Q’. If there is another concentric sphere S2 of the radius r2 (r2

> r1) and there be no additional charges between S1 and S2, find the ratio of electric flux through S1 and

S2

2. ‘S1’ and ‘S2’ are two hollow concentric spheres enclosing charges ‘2Q’ and ‘4Q’

figure:

(i) What is the ratio of electric flux

through ‘S1’, & ‘S2’? AND S

(ii) How will the electric flux

through the sphere ‘S1’ change

if a medium of dielectric

constant 6 is introduced in the

space inside ‘S1’ in place of air?

3. An electric dipole of dipole moment 20 x 10

coming out of the surface?

4. The figure shows the field lines on a positive charge. Is the work done by the field in moving a small

positive charge from Q to P positive or negative? Give reason.

5. A small metal sphere carrying charge ‘+Q’ is located at the centre of a spherical cavity in a large uncharged

meal sphere as shown in figure

’ are two hollow concentric spheres enclosing charges ‘2Q’ and ‘4Q’ respectively as shown in

What is the ratio of electric flux

’? AND S2 s2

w will the electric flux

’ change

constant 6 is introduced in the

in place of air?

ic dipole of dipole moment 20 x 10-6

Cm is enclosed by a closed surface. What is the net flux

The figure shows the field lines on a positive charge. Is the work done by the field in moving a small

charge from Q to P positive or negative? Give reason.

A small metal sphere carrying charge ‘+Q’ is located at the centre of a spherical cavity in a large uncharged

meal sphere as shown in figure below: Use Gauss’s theorem to find electric field at points P

(CBSE 2005)

4Q

2Q

Metal

Free Space

+Q

r

respectively as shown in

Cm is enclosed by a closed surface. What is the net flux

The figure shows the field lines on a positive charge. Is the work done by the field in moving a small

A small metal sphere carrying charge ‘+Q’ is located at the centre of a spherical cavity in a large uncharged

below: Use Gauss’s theorem to find electric field at points P1 & P2.

6. A spherical Gaussian surface encloses a charge of 8.85 x 10-8

C. (a) Calculate the electric flux passing

through the surface, & (ii) if the radius of the Gaussian surface is doubled, how would the flux change?

7. State Gauss’s theorem & its application. (CBSE 2005, 2005 S, 2006, 2007 & 2007S)

8. Two point charges 4μc and -2μc are separated by a distance of 1 m in air. At what point on the line joining

the charges is the electric potential zero?

9. Name the physical quantity which has its unit joule coulomb-1

. Is it a scalar or a vector?

10. An uncharged insulated conductor ‘A’ is brought near a charged insulated conductor ‘B’. What

happens to the charge & potential of ‘B’?

11. What is the work done if a point charge ‘+q’ is taken from point ‘A’ to point ‘B’ on the circumference of a

circle drawn with another charge ‘+q’ at the centre?

12. A 500 mC charge is at the centre of a square of side 10 cm. Find the work done in moving a charge of 10 mC between two diagonally opposite points

on the square.

13. How does the electric flux, electric field enclosing a given charge vary when the area enclosed by the

charge is doubled?

14. The electric field in a certain region of space is ��� = 104� ���. How much is the flux passing through an

area ‘A’ if it is a part of XY plane, XZ plane, YZ plane, making an angle 300

with the axis?

15. Two electric charges 3μC, -4μC are placed at the two corners of an isosceles right angled triangle of side 1

m as shown in the figure. What is the direction and magnitude of electric field at A due to the two

charges?

16. A sensitive instrument is to be shifted from a strong electric field in its environment. Suggest a possible

way.

17. Derive the expression for the electric potential at any point along the axial line of an electric dipole ?

18. Three charges –q, Q and –q are placed at equal distances on a straight line. If the potential energy of

system of these charges is zero, then what is the ratio of Q:q

19. Sketch the electric field lines, when a positive charge is kept in the vicinity of an uncharged conducting

plate.

A

1 m 3μC 4μC

B C

22. Find the capacitance of arrangement of 4 plates of Area A at distance d in air as shown.

25. What is an equivalent capacitance of the arrangement the shown below. If 6V cell is connected across AD.

Calculate the potential difference between B&C.

20. How will you connect seven capacitors of 2µf to obtain an effective capacitance of 10/11 µf.

21. Show that the potential of a charged spherical conductor, kept at the centre of a charged hollow spherical

conductor is always greater than that of the hollow spherical conductor, irrespective of the charge

accumulated on it.

22. What happens to the capacitance of a capacitor when a copper plate of thickness one third of the

separation between the plates is introduced in the capacitor?

23. A parallel plate capacitor is charged and the charging battery is then disconnected. What happens to the

potential difference and the energy of the capacitor, if the plates are moved further apart using an

insulating handle?

24. Find the equivalence capacitance between X and Y.

3 µf 3 µf 3 µf Y

X

26. A parallel plate capacitor is charged to a potential difference V by d.c. source and then disconnected. The

distance between the plates is then halved. Explain with reason for the change in electric field,

capacitance and energy of the capacitor.

27. Derive an expression for capacitance of parallel plate capacitor, when a dielectric slab of dielectric

constant k is partially introduced between the plates of the capacitor

28. Draw a graph to show the variation of potential applied and charge stored in a capacitor. Derive the

expression for energy stored in a parallel plate capacitor from the capacitor.

29. Define dielectric constant in terms of the capacitance of a capacitor.

.

32.

33.

34.

35.

36.

37.

38. A charge QµC is placed at the centre of a cube. What is the electric flux coming out from any one

surface?

39. (a) Plot a graph comparing the variation of potential ‘V’ and electric field ‘E’ due to a point charge ‘Q’

as a function of distance ‘R’ from the point charge.

(b) Find the ratio of the potential differences that must be applied across the parallel and the

series combination of two identical capacitors so that the energy stored, in the two cases,

becomes the same.

40. (a) How is the electric field due to a charged parallel plate capacitor affected when a dielectric

slab is inserted between the plates fully occupying the intervening region?

(b) A slab of material of dielectric constant K has the same area as the plates of a parallel plate

capacitor but has thickness1/2d, where d is the separation between the plates. Find the expression for the

capacitance when the slab is inserted between the plates.

41. Find the ratio of the poetntial differences that must be applied acros the parallel and the series

combination of two capacitors C1 and C2 with their capacitances in the ratio 1: 2 so that the energy stored,

in the two cases, becomes the same.

42.

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ENGLISH

1.Complete summary “ The Invisible Man”

Character sketch – all character

Articles – 1.Global Warming

2. Swacch Bharath Abhiyan

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