Bhagya

CBSE Previous Year Solved  Papers  Class 12 Chemistry Outside Delhi 2016

Time allowed: 3 hours                                                                                      Maximum Marks: 70

General Instructions:

1. All questions are compulsory.
2. Questions number 1 to 5 are very short-answer questions and carry 1 mark each.
3. Questions number 6 to 10 are short-answer questions and carry 2 marks each.
4. Questions number 11 to 22 are also short-answer questions and carry 3 marks each.
5. Questions number 23 is a value based question and carry 4 marks.
6. Questions number 24 to 26 are long-answer questions and carry 5 marks each.
7. Use log tables, if necessary. Use of calculators is not allowed.

SET-I

Question.1. What type of magnetism is shown by a substance if moments of domains are arranged same direction ?
Answer : If magnetic moments of domains are arranged in same directions then the ferromagnetic type of magnetism is shown by the substance.

Question.2.

Question.3. On adding NaOH to ammonium sulphate a colourless gas with pungent odour is evolved which forms a blue coloured complex with Cu²⁺ ion. Identify the gas.

Question.4. Write the main reason for the stability of colloidal solutions.
Answer: All the colloidal particles in a given solution carry the same charge and the dispersion medium has an opposite and equal charge; the system as a whole being electrically neutral. This is the main reason for the stability of the colloidal solution.

Question.5. Write the IUPAC name of the given compound.

Question.6. When a coordination compound CrCl₃.6H₂O is mixed with AgNO₃, 2 mole of AgCl are precipitated per mole of the compound. Write
(i) Structural formula of the complex.
(ii) IUPAC name of the complex
Answer: (i) Structural formula of the complex is [Cr (H₂0)₅ Cl] Cl₂. H₂0, because two mole of chlorine are outside coordination entity to form two mole of AgCl from per mole compound.
(ii) Pentaaquachloride chromium(III) chloride monohydrate.

Question.7. From the given cells :
Lead storage cell, Mercury cell, Fuel cell and Dry cell Answer the following;
(i) Which cell is used in hearing aids ?
(ii) Which cell was used in Apollo Space Programme ?
(iii) Which cell is used in auto mobiles and inverters ?
(iv) Which cell does not have long life ?
Answer : (i) Hearing aid—Mercury cell.
(ii) Apollo Space Programme—Fuel cell.
(iii) Automobile and inverters—Lead storage cell.
(iv) Cell does not have long life—Dry cell.

Question.8. When chromite ore FeCr₂0₄ is (used with NaOH in presence of air, a yellow coloured compound (A) is obtained which on acidification with dilute sulphuric acid gives a compound (B), compound (B) on reaction with KCl forms a orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and (C).
(ii) Write one use of compound (C).
OR
Complete the following chemical equations :

Question.9. Write the mechanism of the following reaction :

Answer : Formation of ether from alcohol is a nucleophilic bimolecular reaction (S_N2). A protonated alcohol is attacked by another alcohol molecule.

Question.10.

(i) Write the order and molecularity of this reaction.
(ii) Write the unit of k.
Answer: (i) For any reaction; Rate = K [A] order
[A] = concentration of reactant.
Hence its a zero order reactions and its molecularity is two.
(ii) Unit of K for a zero order reaction is mol L^-1 sec^-1.

Question.11. The rate constant for the first order decomposition of H₂O₂ is given by the following equation :

Calculate Ea for this reaction and rate constant K if its half life period be 200 minute. (Given : R = 8.314 J K^-1 mol^-1)

Question.12. (i) Differentiate between adsorption and absorption.
(ii) Out of MgCl₂ and AlCl₃ , which one is more effective in causing coagulation of negatively charged sol and why ?
(iii) Out of sulphur sol and proteins, which one forms multi molecular colloids ?
Answer:

(ii) According to Hardy-Schulze law the ions carrying opposite ‘ charge to that on sol are responsible for coagulation of the sol. These are called active ions. Hence as the sol is negative, Mg²⁺ and Al⁵⁺ ions will cause coagulation. As coagulation power of electrolyte is proportional to the valency of oppositely charged ion, so AlCl₃ will be more effective than MgCl₂ .
(iii) Out of sulphur sol & protein, sulphur sol will form multi molecular colloids. As the particles are similar than 10³ pm. So they form aggregate to form sol. sulphur sol consists of S₈ molecules.

Question.13. Give reasons:
(i) C-Cl bond length in chlorobenzene is shorter than C-Cl bond length in CH₃—Cl.
(ii) The dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.
(iii) S_N1 reactions are accompanied by racemization in optically active alkyl halides
Answer: (i) C — Cl bond length in chlorobenzene is shorter than CH₃ – Cl, C – Cl bond as in chlorobenzene due to resonance C-Cl bond has partial double bond character which reduces the bond length.
(ii)In cyclohexyl chloride, carbon in C – Cl bond is sp³ hybridised whereas in chlorobenzene C – Cl bond carbon is sp² hybridised sp² is more electronegative than sp³ carbon. Hence C — Cl bond of chlorobenzene less polar.
(iii) In S_N1 reaction a carbocation intermediate is formed. In case of optically active albyl halide the attack of nucleophile in the next step to carbocation can occur from both the faces of the trigonal planar species in equal probability. Thus 50 : 50 racemic mixture is obtained.

Question.14. An element crystallizes in a f.c.c. lattice with cell edge of 250 pm. Calculate the density if 300 g of this element contain 2 x 10²⁴ atoms.

Question.15. Give reasons :
(i) Mn shows the highest oxidation state of + 7 with oxygen but with fluorine it shows the highest oxidation state of + 4
(ii) Transition metals show variable oxidation states.
(iii) Actinoids show irregularities in their electronic configurations.
Answer : (i) oxygen has a greater capacity to stabilised the highest oxidation state of a particular metal than fluorine because it can form multiple bonds in oxide (double bond) which is not possible in case of fluoride. ‘
(ii) Transition metals show variable oxidation state because of use of ns and (n-1) d shell electrons while bonding as the shells have similar energy.
(iii) Actinoids show irregularities in their electronic configurations because 6d, Is and 5f electrons/shells have less energy difference and electrons can be accommodated in any of them.

Question.16. Write the main product(s) in each of the following reactions :

Question.17. (i) Name the method of refining of metals such as Germanium.
(ii) In the extraction of Al, impure Al₂O₃ is dissolved in cone. NaOH to form sodium aluminate and leaving impurities behind. What is the name of his process ?
(iii) What is the role of coke in the extraction of iron from its oxides ?
Answer : (i) Zone refining method used for refining of metals such as germanium which is based on the principle that the impurities are more soluble in the meat than in the solid state of the metal.
(ii) Leaching: This method consists of treating the powdered ore with a suitable reagent which can selectively dissolve the ore but not the impurities.
(iii) Coke act as a reducing agent and it reduces the iron ore hematite.

Question.18. Calculate e.m.f. of the following cell at 298 K.

Question.19. (i) Write the name of two monosaccharides obtained on hydrolysis of lactose sugar ?
(ii) Why Vitamin C cannot be stored in our body ?
(iii) What is the difference between a nucleoside and nucleotide ?
Answer: (i) The two monosaccharides are β-D-galactose and β-D- glucose.
(ii) Vitamin C is, an water soluble,, vitamin and hence get excreted by urine. So it cannot be stored in body and needs to be supplemented regularly.
(iii) When a base (purine or pyriamidine) get attached to T position of a pentose sugar a nucleoside is formed. When a nucleoside is further linked to phosphoric acid at 5′ position of sugar moeity, we get a nucleotide.

Question.20, (a) For the complex [Fe(CN)₆]^3- write the hybridization type, magnetic character and spin nature of the complex, (pt number Fe = 26).
(b) Draw one of the geometrical isomers of the complex [Pt (en)₂ Cl₂]²⁺, which is optically active ?
Answer:

Question.21. Write the structure of A, B and C in the following :

Answer:

Question.22. (i) What is the role of t-butyl peroxide in the polymerization of ethane ?
(ii) Identify the monomers in the following polymer :

(iii) Arrange the following polymers in the increasing order of their inter molecular forces. Polystyrene, Terylene, Buna-S.
OR
Write the mechanism of free radical polymerisation of ethene. 
Answer : (i) Polymerisation of ethene to low density polyethene (L.D.P.) needs presence of a free radical generating initiator (catalyst), t-butyl peroxide helps in starting the chain of radical formations.

Question.23. Due to hectic and busy schedule Mr. Angad made his life full of tensions and anxiety. He started taking sleeping pills to overcome the depression without consulting the doctor. Mr. Deepak a close friend of Mr. Angad advised him to stop taking sleeping pills and suggested to change his lifestyle by doing Yoga, meditation and some physical exercise. Mr. Angad followed his friend s advice and after few days he started feeling better. After reading the above passage answer the following:
(i) What are the values (at least two) displayed by Mr. Deepak.
(ii) Why is it not advisable to the sleeping pills without consulting doctor.
(iii) What are tranquilizers ? Give two examples.
Answer : (i) Values displayed by Mr. Deepak ;
(a) Knowledge of side effects of pills without prescription.
(b) Friendship
(ii) Sleeping pills are tranquilizers and may cause harmful side effects and act as poison. Hence a doctor must be consulted to regularise the doses of such drugs.
(iii) Tranquilizers are a class of druge or chemicals which are used to treat stress and mental disease. Example : proniazid and Equanil.

Question.24. (a) Write the structures of A, B, C, D and E in the following reactions:

OR
(a) Write the chemical equation for the reaction involved in Cannizzaro reaction.
(b) Draw the structure of the semicarbazpne of ethanal.
(c) Why _pKa of F-CH₂-COOH is lower than that of CI-CH₂-COOH ?
(d) Write the product in the following reaction ,

(e) How can you distinguish between propanal and proanone ?

OR
(a) For aldehydes which do not have a-hydrogen atom self oxidation and reduction takes place in presence of concentrated alkali. This produces one mole of alcohol and one. mole of salt of carboxylic acid. This is called Cannizzaros reaction.

(e) Tollens reagent will give a positive test of silver mirror formation with propanal.
Aldehyde can oxidise Tollens’ reagent to metallic silver but ketones cannot.

Question.25. (a) Calculate the freezing point of solution when 1.9 g (of MgCl₂ (M = 95 g/mol) was dissolved in 50 g of water, assuming MgCl₂. Undergoes complete ionization. (K_f for water = 1.86 K kg mol^-1)
(i) Out of 1 M glucose and 2 M glucose, which one has a higher boilling point and why ?
(ii) What happens when the external pressure applied becomes more than the osmotic pressure of so lution ?
OR
When 2.56 g of sulphur was dissolved in 100 g of CS₂, the freezing point lowered by 0.383 K. Calculate the formula of sulphur (S_x).
(K_f for CS₂ = 3.83 K kg mole-1, Atomic mass of sulphur = 32 g/mol^-1).
Blood cells are isotonic with 0.9% sodium chloride solution what happens if we place blood cells in a solution containing.
(i) 1.2% sodium chloride solution ?
(ii) 0.4% sodium chloride solution ?
Answer:

(b) (i) 2M glucose will have higher boiling point because boiling point of a solution of a non-volatile liquid increases with increase in concentration
(ii)When external pressure applied is more than the osmotic pressure then reverse osmosis takes place. The solvent will then flow from the solution to the five solvent by semipermeable membrane.
OR


(b) (i) 1.2 % Sodium chloride is hypertonic than blood cells, hence cells will shrink. Plasmolyis will take place.
(ii) 0.4% Sodium chloride solution is hypotonic than blood cell, so cells will swell. Endo osmosis will take place.

Question.26. (a) Account for the following:
(i) Ozone is Thermodynamically unstable.
(ii) Solid PCl₅ is ionic in nature.
(iii) Fluorine forms only one oxoacid HOF.
(b) Draw the structure of: (i) Br₅ (ii) XeF₄
OR
(i) Compare the oxidising action of F₂ and Cl₂ by considering parameters such as bond dissociation enthalpy, electron gain enthalpy and hydration enthalpy.
(ii) Write the conditions to maximize the yield of H₂SO₄ by contact person.
(iii) Arrange the following in the increasing order of property mentioned.
(a) H₃PO₃, H₃PO₄, H₃PO₂ (Reducing Characters)
(b) NH₃, PH₃, ASH₃, SbH₃, BiH₃ (Base strength)
Answer : (a) (i) Ozone easily decompose to give nascent oxygen:
O₂ —> O₂ + [O], because to reaction is exothermic (ΔH —> -ve) and results in increase in entropy (Δs time). Over all Gibbs energy change in quite high and negative.
(ii) In solid state PCI5 exist as [PCl₄]+ [PCl₆]-. The cation is tetrahedral and in formed by breaking of weaker P—Cl axial bonds of trigonal bipyramidal structure to form [PCl₄]⁺ and it Bond ionically with octahedral [PCl₆]^– .
(iii) Because of high electro negativity and small size fluorine forms only one oxO acid, HOF.

OR
(i) (a) F₂ is a stronger oxidising agent than chlorine parameters;
(b) Bond dissociation enthalpy of F₂ is less than chlorine.
(c) Electron gain enthalpy of Cl₂ is more negative than F₂, because of bigger size and less repulsion. Also because of small size the hydration enthalpy of F₂ is quite high than Cl₂.
(d) Altogether bond dissociation enthalpy and high hydration enthalpy compensates the smaller electron stronger oxidising agent than Cl₂.
(ii) (a) A moderately low temperature of about 720 K and high
pressure of about 2 bar yields maximum H₂SO₄ acid.
(b) Its an exothermic reaction and forward reaction causes decrease in pressure.
(iii) (a) H₃PO₄ < H3PO₃ < H₃PO₂.
(b) BiH₃ < SbH₃ < ASH3 < PH₃ < NH₃.

Looking for an easy way to Learning of new elementary english grammar and composition for class 8 answers, Solutions. You have to learn basic English Grammar topics like Tenses Verbs, Nouns, etc… In this article, we will review the best English Grammer Topics and compare them against each other.

Coherence is the product of many different factors, which combine to make every paragraph, every sentence, and every phrase contributes to the meaning of the whole piece.

Cohesion And Coherence Exercises for Class 8 Examples PDF

Coherence in writing is much more difficult to sustain than coherent speech simply because writers have no nonverbal clues to inform them if their message is clear or not.

Therefore, writers must make their patterns of coherence much more explicit and much more carefully planned. Coherence itself is the product of two factors – paragraph unity and sentence cohesion.

Paragraph Unity
To achieve paragraph unity, a writer must ensure two things only. First, the paragraph must have a single argument that serves as the focus of attention, that is, a topic sentence. Secondly, a writer must control the content of every other sentence in the paragraph’s body such that (a) it contains more specific information than the topic sentence and (b) it maintains the same focus of attention as the topic sentence.

This generalisation about paragraph structure holds true for the essay in particular. The two major exceptions to this formula for paragraph unity are found in fiction (where paragraph boundaries serve other functions, such as indicating when a new speaker is talking in a story) and in journalism (where paragraphs are especially short to promote ‘visual’ ease by creating white space).

Sentence Cohesion

To achieve cohesion, and link one sentence to the next, consider the following techniques:

1.	Repetition: In sentence B (the second of any two sentences), repeat a word from sentence A.
2.	Synonym: If direct repetition is too obvious, use a synonym of the word you wish to . repeat. This strategy is call ‘elegant variation.’
3.	Antonym: Using the ‘opposite’ word, an antonym, can also create sentence cohesion, since in language antonyms actually share more elements of meaning than you might imagine.
4.	Pro-forms: Use a pronoun, pro-verb, or another pro-form to make explicit reference back to a form mentioned earlier.
5.	Collocation: Use a commonly paired or a highly probable word to connect one sentence to another.
6.	Enumeration: Use overt markers of sequence to highlight the connection between ideas. This system has many advantages: (a) it can link ideas that are otherwise completely unconnected, (b) it looks formal and distinctive, and (c) it promotes a second method of sentence cohesion, discussed in point (7) below.
7.	Parallelism: Repeat a sentence structure. This technique is the oldest, most overlooked, but probably the most elegant method of creating cohesion.
8.	Transitions: Use a conjunction or conjunctive adverb to link sentences with particular logical relationships.
9.	Identity: It indicates similarity words that indicate similarity are that is, that is to say, in other words, etc.
10.	Opposition: It indicates contrast words that indicate contrast are but, yet, however, nevertheless, still, though, although, whereas, in contrast, rather, etc
11.	Addition: It indicates continuation words that indicate continuation are and, too, also, furthermore, moreover, in addition, besides, in the same way, again, another, similarly, a similar, the same, etc.
12.	Cause and effect: It describes missing words that indicate are therefore, so, consequently, as a consequence, thus, as a result, hence, it follows that, because, since, for, etc.
13.	Indefinites. It indicates a logical connection of an unspecified type. Words that indicate a logical connection are in fact, indeed, now, etc.
14.	Concession. It indicates a willingness to consider the other side. Words that perform this function are admittedly, I admit, true, I grant, of course, naturally, some believe, some people believe, it has been claimed that, once it was believed, there are those who would say, etc.
15.	Exemplification. It indicates a shift from a more general or abstract idea to a more specific or concrete idea. Words that perform this function are for example, for instance, after all, an illustration of, even, indeed, in fact, it is true, of course, specifically, to be specific, that is, to illustrate, truly, etc.

Cohesion And Coherence Exercises Solved Example With Answer for Class 8 CBSE

Combine the sentences in each set into two clear and concise sentences, eliminating any needless repetition. As you do so, add a transitional word or phrase (in italics at the head of each set) to the beginning of the second sentence to show how it relates to the first. The first one has been done for you.

1. Instead
Retirement should be the reward for a lifetime of work.
It is widely viewed as a sort of punishment.

Retirement should be the reward for a lifetime of work. Instead, it is widely viewed as a sort of punishment for the old.

It is a punishment for the old.

Cohesion And Coherence Exercises Practice Example for Class 8 CBSE

2. Therefore
In recent years viruses have been shown to cause cancer in chickens.

Viruses have also been shown to cause cancer in mice, cats, and even in some primates. Viruses might cause cancer in humans.

This is a reasonable hypothesis.

3. In fact
We do not seek solitude.
If we find ourselves alone for once, we flick a switch.
We invite the whole world in.

The world comes in through the television screen.

4. On the contrary
We were not irresponsible.
Each of us should do something.
This thing would be of genuine usefulness to the world.

We were trained to think that.

5. However
Little girls, of course, don’t take toy guns out of their hip pockets.
They do not say “Pow, pow” to their neighbours and friends.
The average well-adjusted little boys do this.

If we gave little girls the six-shooters, we would soon have double the pretend body count.

6. Next
We drove the wagon close to a corner post.
We twisted the end of the wire around it.
We stapled it fast.
We drove along the line of posts.

We drove for about 200 yards.
We unreeled the wire on the ground behind us.

7. Indeed
‘We know very little about pain.
What we don’t know makes it hurt all the more.
There is ignorance about pain.

No form of illiteracy in the United States is so widespread.
No form of illiteracy in the United States is so costly.

8. Moreover
Many of our street girls can be as vicious as any corporation president.
Many of our street girls can be as money-mad as any corporation president.

They can be less emotional than men.
They can be less emotional in conducting acts of personal violence.

9. For this reason
The historical sciences have made us very conscious of our past. They have made us conscious of the world as a machine.
The machine generates successive events out of foregoing ones.

Some scholars tend to look totally backward.
They look backward in their interpretation of the human future.

10. However
Rewriting is something that most writers find they have to do.
They rewrite to discover what they have to say.
They rewrite to discover how to say it.
There are a few writers who do little formal rewriting.
They have capacity and experience.
They create and review a large number of invisible drafts.

CBSE Class 9 Science Practical Skills – Sound

Basic Building Concepts
The important experience in our everyday life is the sensory experience, for this we are equipped with ears for the detection of sound.
Basically, all types of sounds which we experience are created by vibrating objects and propagate through a material medium as a wave, i.e. a medium transports the mechanical energy created by the vibrating particle from one point to another without shifting the material particles of the medium.
For human beings, the range of hearing is limited to frequencies 20Hz to 20kHz, whereas a dog can perceive vibration higher than 20 kHz, i.e. upto 45000 Hz.

You can also Download Class 9 Science Notes PDF to help you to revise complete Syllabus and score more marks in your examinations.

Wave
The continuous disturbance which travels through a medium, transporting the energy from one point of the medium (i.e., the point where the disturbance is created) to the other point without being shifted the material is called a wave.

Nature of Sound Wave
Sound waves are the longitudinal waves because the vibration of the particle in a medium is parallel to the direction of propagation of the wave. As a result compression and rarefaction regions are formed. These involve changes in volume and density of the medium.
Compression: The regions where the particles of the medium become closer during vibration, i.e. high pressure regions are called compressions.
Rarefaction: The regions where the particles of the medium are farther apart from each other, i.e. low pressure regions are called rarefactions.

Characteristics of Wave Motion

1. Only the disturbance created by the source in a medium travels through the medium. Medium does not move as a whole.
2. Only energy is transported from one point to another point in a medium.
3. There is no transfer of the matter through the medium.
4. Particles of the medium do not travel during the propagation of the wave from one point to another.

Characteristics of the Medium for the Propagation of the Wave

1. Medium should be elastic to store the potential energy.
2. Medium should possess the inertia or mass to store the kinetic energy.
3. Medium should have uniform density.

Due to these properties, medium can offer an opposition to change in volume. All the media, solids, liquids and gases possess these properties. Therefore, longitudinal waves can be propagated through all of them.

Propagation of Sound Waves in Air
Sound is emitted by the vibrating source. A vibrating source produces sound waves in the surrounding medium. As the wave moves, the air particles which are in contact with the vibrating source are first displaced from their equilibrium position, exert a force on the neighbours causing them to be displaced from their equilibrium position and come back to their original position. This process is continued. As a result, high air pressure regions called compressions and low air pressure regions called rarefactions are formed in the air, thereby producing a sensation of hearing in our ears.

Speed of Sound
The speed of sound depends on the nature of the medium through which the waves pass. It is proportional to the square root of the

• ratio of the elasticity of the medium to its density
• temperature of the medium
  Presence of moisture increases the velocity of sound in air because the density of dry air is greater than the density of moist air.
  At 20 °C temperature, the speed of sound in air is approximately 343 m/s, in water, it is 1482 m/s and in steel, it is 5960 m/s. The speed of sound in air at 0 °C is 332 m/s.

Behaviour of Sound Wave
At the interface of the two media, sound waves show four possible behaviours:

1. Reflection(back into the same medium but in the different direction when it falls obliquely and obey the law of reflection same as in light).
2. Refraction(moves into the second medium).
3. Diffraction(bending around the obstacle without crossing the interface).
4. Transmission(crossing the interface into the new material or obstacle).

Reflection of Sound
Whenever a sound wave gets reflected from an open end, there will not be any change in the disturbance propagated in a medium, i.e. compression/rarefaction will reflect and return as a compression/rarefaction. If the waves, get reflected from a fixed or rigid support end, there will be a change in the disturbance, i.e. compression will reflect and return as a rarefaction while rarefaction will reflect and return as a compression.
Thus, the disturbance which returns in the same medium but in a different direction after striking an extended surface is known as reflection of sound wave. The incident angle and reflected angle are equal. Since the wavelength of sound wave is very large as compared to the wavelength of light wave. Therefore, for reflection of sound waves:

• Extended surface is needed.
• Size of obstacle should be large.
• Surface need not necessarily be smooth or polished.
• Surface may or may not be curved.

Practical Applications of Reflection of Sound Wave
The following instruments work on the principle of reflection of sound:

• Megaphones or loudspeakers have horn-shaped openings.
• Ear trumpet or hearing aid devices.
• Concave reflecting soundboards.
• Stethoscopes used by doctors.

The reflection of sound also becomes important to the design of concert halls, cinema halls and auditoriums. The walls of such building is built from materials that reflect the sound towards audience.

Aim
To verify the laws of reflection of sound.

Apparatus Required
One clock or watch with a quiet tick, two similar cylindrical hollow cardboard tubes of 30-50 cm length, rough or smooth sound reflecting surface, drawing board, white paper sheet, cardboard.

Theory
When a sound wave falls on an extended surface or obstacle of large size, it gets bounced back into the same medium but in different direction. This phenomenon is known as reflection of sound.
The laws of reflection for the sound waves are:

• The angle of incidence made by the sound waves with the normal to the reflecting surface is equal to the angle of reflection in which sound waves get reflected, i.e.∠i = ∠r.
• The incident sound wave, reflected wave and the normal at the point of incidence, all lie in the same plane.
  

Procedure

1. Fix a white plane paper on drawing board with the help of drawing pin at the four corners of white paper.
2. Draw a line XY along one edge of the paper. At any point P on this line, draw a normal PN.
3. Using protractor, make an incident angle of 30° with the normal PN and mark it as ∠APN.
4. Place a reflecting surface, such as stiff cardboard/plywood/glass slab/mirror on a line XY in upright position with the help of stand/modeling clay.
5. Place another cardboard along normal act as a screen. This does not allow the direct hearing of the ticking sound of the clock.
6. Arrange two cylindrical hollow cardboard tube in such a way that their open ends come close together as shown in the figure.
7. Keep a clock near the open end of the tube placed on the line AP.
8. Try to listen the clear and distinct ticking sound of the clock through the other tube placed on the other side of the screen by adjusting the position of the tube. Mark this position as B. Distinct sound can be heard because sound waves get reflected from the reflecting surface.
9. Lift the end B of pipe PB, vertically upward to a small height. Try to hear the sound of the table-clock now through the pipe PB.
10. Lift the tubes, reflecting surface and screen. Join the points B and P and measure the angle of reflection of sound wave.
11. Repeat the experiment by taking different values of angle of incidence and tabulate your observations.
    

Observations

S.No.	Angle of incidence of sound wave ∠i	Angle of reflection of sound wave ∠r	Error ∠i – ∠r
1.	30°
2.	45°
3.	60°
4.	75°

 When the end B of the pipe PB is lifted vertically upward to a small height, the sound of the table-clock is either weakened or diminished completely.

Result
From the observations, we conclude that

1. within experimental error limit, angle of incidence is always/approximately equal to the angle of reflection.
2. the incident sound wave, reflected wave and the normal at the point of incidence all lie in the same plane. Hence the law of reflection of sound is verified.

Precautions

1. Reflecting surface and screen should be held vertically on the sheet of paper.
2. Position of the ticking clock should be along the axis of the hollow cylindrical tube placed along AP.
3. Mark the position of the second tube only when heard sound intensity of the ticking clock is maximum.
4. Ear, ticking clock and reflecting surface should be in the same plane.
5. Utmost care should be taken while taking the measurement of angle. The measurement of angle, either it is incident or reflection must be taken between the axis of the tube and the normal.

Interactive Session

Question 1.
What is the aim of the experiment given to you?
Answer:
The aim of my experiment is to verify the laws of reflection of sound.

Question 2.
How can you explain the reflection phenomenon in sound?
Answer:
When a sound wave falls on a hard surface having a large size like wood, stiff cardboard, it bounces back into the same medium but in different direction. This phenomenon is called reflection of sound wave.

Question 3.
Suppose when you shout inside an empty hall, you hear your own sound after a short time. Why is it happen?
Answer:
It happens because our sound is reflected from the walls of empty hall.

Question 4.
Can you choose any hard and plane wooden surface which serve as a reflector of sound?
Answer:
Yes, any hard and plane wooden surface can serve as a reflector of sound waves.

Question 5.
Why?
Answer:
The wavelength of sound wave is very large as compared to the wavelength of light wave.

Question 6.
What is the use of wooden screen placed between the two tubes?
Answer:
It cuts off the direct sound from watch to ear.

Question 7.
What conclusion would you draw when the axes of both the tubes are inclined equally to the normal?
Answer:
The angle of incidence (i) is equal to the angle of reflection (r).

Question 8.
Which fundamental law is followed by the mechanical wave?
Answer:
Laws of reflection.

Question 9.
Which physical phenomenon is also based on reflection of sound waves?
Answer:
Phenomenon of echo.

Question 10.
Which type of medium is necessary for the propagation of mechanical waves?
Answer:
A material medium.

Question 11.
What should be the properties of the medium for the propagation of sound waves?
Answer:
The medium must possess three properties, viz. elasticity, inertial and minimum friction, and density of the medium.

Question 12.
What is the physical cause that produces the sensation of hearing?
Answer:
Vibrations of the source.

Question 13.
Give two applications in real-life where reflection of sound plays an important role?
Answer:
The ear trumpt or hearing aid, reflecting boards fixed inside the walls of large movie hall/auditorium.

Question 14.
In which form longitudinal wave motion travels in a medium?
Answer:
It travels in the form of compression and rarefaction in the medium.

Question 15.
‘What are the changes involve in a medium during the propagation of longitudinal waves?
Answer:
Change in volume and density of the medium.

Question 16.
Why the sound waves cannot travel through air in the form of transverse waves?
Answer:
Because crest and trough cannot be sustained in air.

NCERT Lab Manual Questions

Question 1.
While performing this experiment, why do we prefer to use pipes of larger length but of smaller diameter?
Answer:
In this experiment, it is assumed that sound source is directional. Practically, due to the presence of unwanted sound in our surroundings, sound coming from source will not remain unidirectional. Therefore, it is advised to use the pipes of larger length but of smaller diameter.

Question 2.
How the experiment of reflection of sound is different from the experiment on laws of reflection of light?
Answer:
For the reflection of sound wave, the surface may be polished or rough while the reflecting surface for light wave should be smooth and well polished.

Question 3.
Which sheet will you choose as sound reflecting surface for this experiment;
(a) A smooth wooden board or (b) A thermocol sheet? Why?
Answer:
A smooth wooden board will be chosen as sound reflecting surface because reflection from this surface will be more. Thermocol sheet acts as a good absorber of sound.

Question 4.
Suppose the whole experimental set-up of this experiment is submerged in water. What changes do you expect in your observations?
Answer:
The speed of sound in water at 20 °C is 1482 ms-1 while in air it is 343 ms-1 at 20 °C. Therefore, when the whole experimental set-up is submerged in water, the reflected sound will be heard faster as compared to air.

Question 5.
Why do we require a low amplitude sound source in this experiment?
Answer:
If we take the high amplitude sound source, then we may hear the sound from the source to our ear directly and not through the reflecting ray pipe. Therefore, it is required to have a low7 amplitude sound source in this experiment.

Question 6.
What alterations can be made in the pipes to make the reflected sound more distinct and clear?
Answer:
In order to absorb all unwanted sound rays from our surroundings and to make the reflected sound more distinct and clear, the inner surfaces of two pipes should be painted black and kept rough. A rough paper is a good absorber of sound so when we use plastic pipes, a layer of newspapers may be inserted into these pipes.

Practical Based Questions

Multiple Choice Questions/VSA (1 Mark)

Question 1.
Which of the following is the correct experimental set-up for verification of laws of reflection of sound? [CBSE 2010]

(a) A
(b) B
(c) C
(d) D

Question 2.
In the experiment of verification of reflection of sound, the incident sound is directed along
[CBSE 2010]
(a) axis of tube
(b) normal to the axis of tube
(c) at an angle of 30° from the axis of the tube
(d) at an angle of 45° from the axis of the tube.

Question 3.
While verifying the laws of reflection of sound, out of following precautions which one should not be followed? [CBSE 2011]
(a) The table top should be horizontal.
(b) Length of pipes should be sufficiently long.
(c) The reflecting surface should be smooth and hard.
(d) Ear should not be placed close to the pipe.

Question 4.
While doing experiment on verifying the law of reflection of sound, four students measured the angles ∠i and ∠r as shown in the diagram below. The correct measurement of the angle of incidence and angle of reflection has been done by student [CBSE 2011] [CBSE 2010, CBSE Sample Paper]

(a) A
(b) B
(c) C
(d) D

Question 5.
A student while verifying the laws of reflection of sound measured the angle between the incident sound wave and reflected sound wave as 130°. The angle of reflection is [CBSE 2012]
(a) 130°
(b) 65°
(c) 90°
(d) 60°

Question 6.
The sound of a stopclock received in the ear while doing the experiment of ‘Reflection of sound’ should be [CBSE 2011][NCT 2009]
(a) the direct sound from the clock.
(b) the sound reflected from the ceiling of the laboratory.
(c) the sound coming through the pipe after reflection from the reflecting surface.
(d) both (a) and (b).

Question 7.
A student performs the experiment of ‘reflection of sound’. He/she records following values of the angle of incidence and angle of reflection. [CBSE 2011]

S.No	Set 1	Set 2	Set 3	Set 4	Set 5
Angle of incidence →	3o°	40°	45°	50°	60°
Angle of reflection →	60°	50°	45°	30°	60°

 The set correctly recorded by him/her are
(a) Set 1 and set 3 respectively.
(b) Set 1 and set 5 respectively.
(c) Set 2 and set 4 respectively.
(d) Set 3 and set 5 respectively.

Question 8.
In order to hear an echo of a sound wave, the minimum distance between the sound producing body and the reflecting surface should be (at normal temperature)
(a) 20 m
(b) 17.2 m
(c) 21.6 m
(d) 24.0 m

Question 9.
When the sound wave propagates, which physical quantity changes in the medium?
(a) Only density
(b) Only pressure
(c) Both density and pressure
(d) Only frequency.

Question 10.
For doing the experiment on verifying the laws of reflection of sound, a student sets up his apparatus as shown. The experiment is more likely to be performed successfully if the screen shown is a [CBSE Sample Paper II]

(a) well polished plane mirror
(b) wooden board with many holes in it
(c) a foam padded board
(d) a sheet of pure white cloth.

Question 11.
If the reflecting surface and the source of sound both are in the plane of the table, the position of the ear of the observer should be
(a) on the same plane
(b) on the plane at an angle of 30° to the table.
(c) on the plane at an angle of 90° below the table
(d) perpendicularly above the source.

Question 12.
Bats search out prey and fly in dark night by
(a) emitting and detecting reflection of ultrasonic wave
(b) emitting and detecting retraction of ultrasonic wave
(c) emitting and detecting reflection of infrasonic wave
(d) all of the above.

Question 13.
Ramjeet, while verifying the laws of reflection of sound, measured the angle between the incident sound wave and reflected sound wave to be 130°. The angle of incidence is [NCT 2008]
(a) Data insufficient
(b) 65°
(c) 130°
(d) 25°

Question 14.
The angle of reflection in the figure depicted is

(a) 60°
(b) 30°
(c) can be 60° or 30°
(d) all options are wrong.

Question 15.
The given figure represents the graph between the angle of incidence and angle of reflection for a sound wave. From this graph, we can conclude that

(а) Angle of incidence decreases with the increase in angle of reflection
(b) Angle of incidence increases with the decrease in angle of reflection
(c) Angle of incidence is always equal to angle of reflection
(d) Angle of incidence sometimes increases and sometimes decreases, depending upon the loudness of sound.

Question 16.
Two students while performing experiment on verification of laws of reflection of sound are provided with the following choices:

• Using a narrow tube or wide tube
• Using a faint source of sound or strong source of sound.

The best results would be obtained by the student using the combination of:
(a) narrow tube and faint source of sound
(b) narrow tube and strong source of sound
(c) wide tube and faint source of sound
(d) wide tube and strong source of sound.

Answers

1. (c)
2. (a)
3. (b)
4. (a)
5. (b)
6. (c)
7. (d)
8. (b)
9. (c)
10. (a)
11. (a)
12. (a)
13. (b)
14. (b)
15. (c)
16. (b)

Short Answer Questions (2 Marks)

Question 1.
In the experiment, to verify the laws of reflection of sound, the tube facing the clock makes an angle equal to 40° with the reflecting surface. What will be the position of the second tube with respect to the normal, at which the ear will get the best reflected sound?
Answer:
For perfect reflection, ∠i = ∠r
Here, 40° + ∠i = 90°
⇒ ∠i = 90° – 40° = 50° = ∠r
Hence, second tube should be placed at angle of 50° with the normal.

Question 2.
Why is it important to have a smooth reflecting surface in the experiment, to verify the laws of reflection of sound?
Answer:
When sound wave is incident on any surface, some part of it is reflected and some part gets absorbed by that surface. For a smooth reflecting surface, the reflection will be more. Hence the sound that you hear through the pipe depends on the nature of the reflecting surface and thus, it is important to have a smooth reflecting surface.

Question 3.
How can you show experimentally in this experiment that the reflected ray lies in the same plane of the incident ray?
Answer:
When the pipe, through which the sound is being heard, is lifted vertically to a small height, the sound from the low-amplitude source such as table-clock or mobile phone is either weakened or diminished completely. It shows that the reflected ray lies in the same plane of the incident ray.

Question 4.
While performing the experiment, to verify the laws of reflection of sound, it is advisable to put the fan off. Why?
Answer:
In this experiment, it is required to hear very low- amplitude sound waves, so peaceful atmosphere is the necessary condition for performing the experiment. To hear such sounds clearly, it is further advised to put the fan off.

Question 5.
Why are curved sound boards and sound absorbent materials used in halls and auditoriums? On which phenomenon of sound it is based?
Answer:
Curved sound boards spread sound uniformly to all places of the hall and auditorium. Draperies and other sound absorbing materials reduce the persistence of sound in hall so that original sound is clearly heard. It is based on the multiple reflections of sound waves from the surface.

Science Practical SkillsScience LabsMath Lab ManualMath Labs with ActivityMath Labs

CBSE Class 9 Maths Lab Manual – Division of a Paper Strip in Equal Parts

Objective
To divide a thin strip of paper into equal parts (7 equal parts).

Prerequisite Knowledge
Intercept Theorem: If there are three (or more) parallel lines and intercepts made by them on any transversal are equal, then intercepts made by them on any other transversal are also equal.

Materials Required
Tracing sheet, colours, ruled sheet of paper, geometry box.

Procedure

1. Cut a rectangular strip of paper from a tracing sheet which is to be divided into 7 equal parts. Name it as ABCD.
   
2. Now, take a ruled sheet, and mark the lines as 0, 1, 2, 3, 4 from top to bottom.
3. Place the paper strip on the ruled sheet such as the point A coincides with line marked 0 and the point D coincides with line marked 7 as shown in the fig. (ii).
   
4. Mark the points on the strip where parallel lines of ruled sheet cuts the strip as X₁, X₂, X₃, X₄, X₅, X₆ on line AD and Y₁, Y₂, Y₃, Y₄, Y₅, Y₆ on line BC.
5. Now draw the lines X₁Y₁, X₂Y₂, X₃Y₃, X₄Y₄, X₅Y₅, X₆Y₆, parallel to AB and colour them as shown in fig. (iii).
   

Observation
X₁Y₁, X₂Y₂, X₃Y₃, X₄Y₄, X₅Y₅, X₆Y₆ divide the paper strip into seven equal parts.

Result
We obtain equally divided strip as AX₁Y₁B = X₁X₂Y₂Y₁ = X₂X₃Y₃Y₂ = X₃X₄Y₄Y₃ = X₄X₅Y₅Y₄ = X₅X₆Y₆Y₅ = X₆DCY₆.

Learning Outcome
Students can divide any rectangular strip in equal parts.

Activity Time
To make fraction chart.

1. Take 9 strips of same size and colour them with different colours.
2. Now by using ruled sheet, divide these strips into 1, 2, 3, 4, 5, 6,……9 equal parts.
3. Paste these divided strips on a chart paper one below the other. See fig. (iv).
4. A beautiful fraction chart is formed.
   Students may use different colour glazed papers to make it attractive and to identify clearly.
   

Viva Voce

Question 1.
How many equal parts of a strip can be done ?
Answer:
Infinite equal parts.

Question 2.
If a strip is divided in 8 equal parts what will be the value of 6 parts ?
Answer:
\(\frac { 6 }{ 8 }\)

Question 3.
What do you mean by intercept theorem ?
Answer:
If there are three (or more) parallel lines and intercepts made by them on one transversal are equal, the intercept on any other transversal are equal.

Question 4.
What is \(\frac { 1 }{ 6 }\) th of a rectangular strip ?
Answer:
A strip is divided into six equal parts, each part is one-sixth.

Question 5.
Can you divide a strip of 7 cm, into 6 equal parts by using ruler ?
Answer:
No.

Question 6.
Why is it necessary to use ruled sheet ?
Answer:
To get a collection of parallel lines at equal distances.

Question 7.
Which theorem is used in the activity ‘Division of a paper strip in equal parts’ ?
Answer:
Intercept theorem.

Question 8.
How many folds are required to divide a rope into 10 equal parts ?
Answer:
9 folds.

Multiple Choice Questions

Question 1.
What is the length of one part of the strip of 7 cm, if it is divided into two equal parts ?
(i) 3.5 cm
(ii) \(\frac { 2 }{ 7 }\) cm
(iii) 4 cm
(iv) none of these

Question 2.
What will be the value of 7 parts of a strip if it is divided into 9 equal parts ?
(i) \(\frac { 1 }{ 9 }\)
(ii) \(\frac { 3 }{ 9 }\)
(iii) \(\frac { 7 }{ 9 }\)
(iv) none of these

Question 3.
If a rectangular strip of 8 cm is divided into 8 equal parts, what will be length of each part ?
(i) 2 cm
(ii) 1 cm
(iii) 3 cm
(iv) none of these

Question 4.
What is the equivalent fraction of \(\frac { 2 }{ 3 }\) ?
(i) \(\frac { 8 }{ 12 }\)
(ii) \(\frac { 1 }{ 3 }\)
(iii) \(\frac { 3 }{ 2 }\)
(iv) none of these

Question 5.
Write two equivalent fractions of \(\frac { 5 }{ 6 }\) ?
(i) \(\frac { 10 }{ 12 } ,\frac { 15 }{ 18 }\)
(ii) \(\frac { 5 }{ 6 } ,\frac { 6 }{ 5 }\)
(iii) \(\frac { 6 }{ 5 } ,\frac { 10 }{ 12 }\)
(iv) none of these

Question 6.
To divide a thread into 11 equal parts, how many successive folds will you give ?
(i) 8
(ii) 10
(iii) 7
(iv) none of these

Question 7.
Which is greater (\(\frac { 23 }{ 25 }\)) or (\(\frac { 12 }{ 5 }\)) ?
(i) \(\frac { 23 }{ 25 }\)
(ii) \(\frac { 12 }{ 5 }\)
(iii) \(\frac { 36 }{ 25 }\)
(iv) none of these

Question 8.
Write two fractions which is equal to 1.
(i) \(\frac { 4 }{ 4 } ,\frac { 6 }{ 6 }\)
(ii) \(\frac { 4 }{ 4 } ,\frac { 2 }{ 3 }\)
(iii) \(\frac { 18 }{ 9 } ,\frac { 24 }{ 12 }\)
(iv) none of these

Question 9.
Add: \(3\frac { 3 }{ 5 } +8\frac { 2 }{ 3 }\)
(i) \(\frac { 184 }{ 15 }\)
(ii) \(\frac { 148 }{ 15 }\)
(iii) \(11\frac { 5 }{ 8 }\)
(iv) none of these

Question 10.
Simplify: \(\frac { 4 }{ 9 } +\frac { 5 }{ 6 } -\frac { 2 }{ 3 }\)
(i) \(\frac { 11 }{ 18 }\)
(ii) \(\frac { 18 }{ 11 }\)
(iii) \(\frac { 15 }{ 9 }\)
(iv) none of these

Answers

1. (i)
2. (iii)
3. (ii)
4. (i)
5. (i)
6. (ii)
7. (ii)
8. (i)
9. (i)
10. (i)

Math Lab ManualMath Labs with ActivityMath LabsScience LabsScience Practical Skills

CBSE Previous Year Solved  Papers  Class 12 Computer Science Outside Delhi 2015

Time allowed : 3 hours                                                                                           Maximum Marks: 70

General Instructions :

1.  There are a total of 26 questions and five sections in the question paper, All questions are compulsory.
2. Section A contains question number 1 to 5, Very Short Answer type questions of one mark each.
3.  Section B contains question number 6 to 10, Short Answer type I questions of two marks each.
4.  Section C contains question number 11 to 22, Short Answer type II questions of three marks each.
5.  Section D contains question number 23, Value Based Question of four marks.
6. Section E contains question number 24 to 26, Long Answer type questions of five marks each.
7. There is no overall choice in the question paper, however, an internal choice is provided in one question of two marks, one question of three marks and all three questions of five marks. An examined is to attempt any one of the questions out of two given in the question paper with the same question number.

SET I

SECTION B

Question.1. (a) How is_init () _different from _del () ?
(b) Name the function/method required to
(i) Check if a string contains only alphabets
(ii) Give the total length of the list.
(c) Rewrite the following code in python after removing all syntax error(s). Underline each correction done in the code.

(d) Find and write the output of the following python code :

(e) Find and write the output of the following python code:

(f) What are the possible outcome(s) executed from the following code ? Also specify the maximum and minimum . values that can be assigned to variable COUNT. TEXT=”CBSEONLINE”

Answer : (a) _init is used to initialise newly created object, and receives arguments used to do that while_del_ is used for destructor
example
class Point:

Question.2. (a) Illustrate the concept of inheritance with the help of a python code.
(b) What will be the output of the following python code ? Explain the try and except used in the code.

(c) Write a class PHOTO in Python with following specifications:

(d) What is operator overloading with methods ? Illustrate with the help of an example using a python code.
(e) Write a method in python to display the elements of list twice, if it is a number and display the element terminated with if it is not a number.
For example, if the content of list is as follows ;

Question.3. (a) What will be the status of the following list after fourth
pass of bubble sort and fourth pass of selection sort used for arranging the following elements in descending order ?
34, -6, 12, -3, 45, 25
(b) Write a method in python to search for a value in a given list (assuming that the elements in list are in ascending order) with the help of Binary Search method. The method sould return -1, if the value not present else it should return position of the value present in the list.
(c) Write PUSH (Names) and POP(Names) methods in
python to add Names and Remove Names considering them to act as Push and Pop operations of Stack.
(d) Write’ a method in pythons, to find and display the
composite numbers between 2 to N. Pass N as argument to the method.
(e) Evaluate the following post fix notation of expression.
Show status of stack after every operation.
34, 23, +, 4, 5, *, –

Question.4. (a) Differentiate between the following:
(i) f = open (‘diary.txt’,’a’)
(ii) f = open (‘diary.text1 , ‘w’)
(b) Write a method in python to read the content from a text file story.txt line by line and display the same on screen.
(c) Consider the following definition of class Student. Write a method in python to Write the content in a pickled file student.dat.

SECTION C

Question.5. (a) Observe the following table carefully and write the names of the most appropriate columns, which can be considered as (i) candidate keys and (ii) primary key :

(b) Consider the following DEPT and EMPLOYEE tables. Write SQL queries for (i) to (iv) and find outputs for SQL queries (v) to (viii).


Note : DOJ refers to date of joining and DOB refers to date of Birth of employees.
(i) To display Eno, Name, Gender from the table EMPLOYEE in ascending order of Eno.
(ii) To display the Name of all the Male employees from the table EMPLOYEE.
(iii) To display the Eno and Name of those employees from the table EMPLOYEE who are born between T987-01-01′ and’1991-12-01′.
(iv) To count and display FEMALE employees who have joined after ‘1986-01-01’.
(v) SELECT COUNT (*), DCODE FROM EMPLOYEE GROUP BY DCODE HAVING COUNT (*) > 1;
(vi) SELECT DISTINCT DEPARTMENT FROM DEPT;
(vii) SELECT NAME , DEPARTMENT FROM EMPLOYEE E , DEPT D
WHERE E . DCODE=D . DCODE AND ENO< 1003;
(viii) SELECT MAX (DOJ) , MIN (DOB) FROM EMPLOYEE;

Question.6. (a) Verily the following using Boolean Laws :
U’ + V = UV + U’ .V + U.V *’
(b) Draw the Logic Circuit for the following Boolean Expression:
(X’ + Y).Z + W’
(c) Derive a Canonical POS expression for a Boolean function F represented by the following truth table:

(d) Reduce the following Boolean Expression to its simplest form using K-Map :

Question.7.(a) Illustrate the layout for connecting 5 computers in a Bus and a Star topology of Networks.
(b) What kind of data gets stored in cookies and how is it useful ?
(c) Differentiate between packet switching over message switching.
(d) Out of the following, which is the fastest (i) wired and
(ii) wireless medium of communication ?
Infrared, Coaxial Cable, Ethernet Cable, Microwave, Optical Fiber.
(e) What is Trojan Horse ?
(f) Out of the following, which all comes under cyber crime ?
(i) Stealing away a brand new hard disk from a showroom.
(ii) Getting in someone’s social networking account without his consent and posting on his behalf.
(iii) Secretly copying data from server of an organization and selling it to the other organization.
(iv) Looking at online activities of a friends blog.
(g) Xcelencia Edu Services Ltd. is an educational organization. It is planning to set up its India campus at Hyderabad with its head office at Delhi. The Hyderabad campus has 4 main buildings – ADMIN, SCIENCE, BUSINESS and ARTS. You as a network expert have to suggest the best network related solutions for their problems raised in (i) to (iv), keeping in mind the distances between the buildings and other given parameters.

(i) Suggest the most appropriate location Of the server
inside the HYDERABAD campus (out of the 4 buildings) to get the best connectivity for maximum number of computers. Justify your answer.
(ii) Suggest and draw the cable layout to efficiently connect various buildings within the HYDERABAD campus for connecting the computers.
(iii) Which hardware device will you suggest to be procured by the company to be installed to protect and control the internet uses within the campus ?
(iv) Which of the following will you suggest to establish the online face-to-face communication between the people in the Admin Office of HYDERABAD campus and DELHI Head Office ?
(i) E-mail
(ii) Text Chat
(iii) Video Conferencing
(iv) Cable TV


(b) A cookie‘s contents are determined by the specific website that created that cookie. Contents vary from site to site. As a general rule, cookies contain random alphanumeric text characters.
Cookies are intended to help you access a site faster and more efficiently. For example, cookies can store information to help you enter a site without having to login.
Message switching is called a store-and-forward technology because the entire message must be received and stored before being sent on to the next system. Email is a good example of this type of technology (the entire email message is sent to an SMTP server before being relayed to another one).
Packet switching involves the breaking down of the message into smaller units, called packets. These packets are then sent one at a time from the sender to the receiver. The packets (or smaller pieces) may be received in any order and are then reassembled back into the original message.
(d) fastest wired medium of communication is Optical Fiber, fastest wireless medium of communication is Microwave
(e) In computers, a Trojan horse is a program in which . malicious or harmful code is contained inside apparently
harmless programming or data in such a way that it can get control and do its chosen form of damage, such as ruining the file allocation table on your hard disk. In one celebrated case, a Trojan horse was a program that was supposed to find and destroy computer viruses. A Trojan horse may be widely redistributed as part of a computer virus.
(f) Out of the following, following comes under cyber crime Getting in someone’s social networking account without his consent and posting pictures on his behalf to Secretly copying files from server of a call center and selling it to the other organization.
(i) The most appropriate location of the server inside the HYDERABAD campus (out of the 4 buildings), is ADMIN block because this block have maximum number of , computers.

(iii) firewall device will be procured by the company to be installed to protect and control the internet uses within the campus.
(iv) Video Conferencing will be best to establish the online face-to-face communication between the people in the Admin Office of HYDERABAD campus and DELHI Head Office.