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CBSE Class 10th Mathematics Question Paper Solution 2015
CBSE Class 10th Mathematics Question Paper Solution 2015 cbse mathematics paper answer key 2015 cbse 10th board maths question & answers with solution 2015. CBSE Board annual exam 2015 for Class 10th is going on. For convenience of students question paper with answer and solution of class 10h for 2015 are available. You can download the question paper of Mathematics for class 10th. Another guidance and help of the students is also appreciating.
Board Paper Solutions (2015) Class: X: Maths 2015 Set 3: Solutions (All India)
For convenience of students question paper with answer and solution of class 10th maths for 2015 are available. You can download and check your answer. For any doubt and mistake comment your view
CBSE Class 10th Mathematics Question Paper Solution Set 30/3
Q. 1. Write the name and formula of the 2nd member of homologous series having general formula CnH2n
Ans: CnH2n+2 is the general formula for the alkane series. So, the second member of the alkane family is ethane
Q.2. what is the magnification of the images formed by plane mirrors and why?
Ans: The magnification of the image formed by a plane mirror is 1. This is because the size of the image formed is equal to the height of the object
Q.3. What is meant by power of a lens?
Ans: The power of a lens the ability of the lens to converge or diverge an incident beam focused on it. P = 1/f
Q.4. Write two differences between binary fission and multiple fission in a tabular form.
Only two daughter cells are produced.
Nuclear division is immediately followed by cytoplasmic division.
More than two daughter cells are produced.
Nuclear division is not immediately followed
Q.5. (a) Why do we need to manage our resources carefully? (b) Why management of natural resources requires a long term perspective?
(a) Since natural resources are limited and its demand is increasing day to day due to growth population
(b) The management of natural resources requires a long-term perspective so that these will last for the future generations
Q6. List four measures that can be taken to conserve forests.
Ans: four measures that can be taken to conserve forests are:
1) Indiscriminate deforestation should be prohibited. 2) Wastage of timber and fuel wood to be avoided.
3) Alternative sources of energy, such as biogas should be used to supplement fuel wood.
4) Forest fires should be prevented.
Q.7. Na, Mg and Al are the elements of the same period of Modern Periodic Table having, one, two and threevalance electrons res. Which of these elements
(i) has the largest atomic radius, (ii) is least reactive? Justify your answer stating reason Solution:
Ans: (i) sodium has the largest atomic radius. On going from left to right in the periodic table, atomic radius decreases due to increase in nuclear pull due to addition of proton.
(ii) Aluminum is the least reactive element. On going from left to right in the periodic table, the reactivity decreases due to increased nuclear charge require more energy to lose electron.
Q.8. From the following elements: 4Be; 9F; 19K; 20Ca
(i) Select the element having one electron in the outermost shell. (ii) Two elements of the same group.
Write the formula of and mention the nature of the compound formed by the union of 19K and element x ( 2 , 8, 7)
Ans: Electronic configuration of 4Be -------- 2, 2.
Electronic configuration of 9F is --------- 2, 7
Electronic configuration of 19 K is --------- 2, 8, 8, 1
Electronic configuration of 20Ca is ------------ 2, 8, 8, 2.
(i) K (ii) Be and Ca
Electronic configuration of element X is 2, 8, 7.
Valency of X = 8 − 7 = 1 and Valency of K = 1
Therefore, the formula of the compound formed when K and element X combine is KX. The compound KX is ionic compound
Q.9. What is meant by isomers? Draw the structures of two isomers of butane, C4H10. Explain why we cannot have isomers first three of alkane series.
Ans: Isomers are the compounds that have the same molecular formula but different structural formulae.
Following are the isomers of butane: CH3CH2CH2CH3 butane
We cannot have isomers first three of alkane series because they cannot branched
Q.10. What is the difference between the molecules of soaps and detergents, chemically? Explain the cleansing action of soap?
Soaps are sodium salt of long chain carboxylic acid where as detergents are the Ammonium or sulphate of long chain of carboxylic acid.
When dirty clothes are mixed with water and soap, the ionic part of the soap being water attractive, dissolves in water whereas the hydrocarbon part of the soap being water repellent unites with the oil or greese part. When dirty clothes are rinsed with water, the dirt particles attached with the soap molecules, dissolve in water and come out. In this way, clothes become clean.
Q.11. what are sexually transmitted diseases. List two example of each diseases caused due to (i) bacterial infection and (ii) viral infections. Which device or devices may be used to prevent the spread of such diseases?
Diseases that are transmitted from one person to other through sexual contact are known as sexually transmitted
Examples of STDs caused by bacterial infection: Gonorrhoea and Syphilis
Examples of STDs caused by viral infection: Herpes and Acquired immunodeficiency syndrome (AIDS)
Use of condoms can prevent the spread of these diseases to a great extent
Q.12. What is DNA copying? State its importance.
Ans: DNA Copying is the process of production of a new DNA molecule from an already existing DNA molecule through chemical reaction. It is accompanied with the creation of new cellular apparatus so that the daughter DNA and parent DNA Importance of DNA copying
1. Copying helps in the transmission of characteristics from parents to offspring.
2. Copying ensure that when cell multiplies, through the mechanisms of mitosis and meiosis, the equal amount of DNA (genetic material) passes in to the new cell.
Q.13. Explain budding in hydra with the help of labeled diagrams only.
Ans: Budding involves the formation of a new individual from a protrusion called the bud. In Hydra, the cells divide rapidly at a specific site and develop as an outgrowth called a bud. These buds, while attached to the parent plant, develop into small individuals. When this individual becomes large enough, it detaches itself from the parent body to exist as an independent individual
Q.14. what is speciation? List four factors responsible for speciation.
Ans: The formation of a new species by evolution or any genetic modification of the previously existing species is called speciation
Following are the factors responsible for speciation: 1. Genetic drift 2. Natural selection 3. Reproductive isolation 4. Geographical isolation
Q.15. (i) Planaria, insects, octopus and vertebrates all have eyes. Can we group eyes of these animals together to establish evolutionary origin? Justify your answer.
(ii) "Birds have evolved from reptiles" State evidence to prove the statement.
Ans: (i) The eyes seen in Planaria, insects, octopus and vertebrates vary greatly in their structure. These organisms can be used for studying evolution of eyes as the eye of Planaria is simple without lens, insects have compound eyes and vertebrates have highly specialized eye however, all of them perform same function, that is, vision. Thus, a common evolutionary origin can be established
(ii) Birds have evolved from reptiles as the connecting link between reptiles and birds is Archaeopteryx, Also there are some similarities in birds and reptiles. Birds have four-chambered heart, which is also a feature of some reptiles. they have separate sexes and internal fertilization occurs in both birds and reptiles.
CBSE Class 10 science Board paper solution 2015 of set -02
2. DNA is found inside a special area of the cell called the nucleus
3. This is because the green plant is the primary producer by trapping energy from sunlight.
4. Absolute refractive index of glass = 4/3 = c/vg
=> 4/3 x vg = c
=> 4/3 x 2 x 108 = c
The speed of light in vacuum = c = 2.67 x108 m/s
Absolute refractive index of water = 3/2 = c/vw
=> The speed of light in water vw = 2c/3 = 1.78 x108 m/s
5. Improper disposal of domestic waster harmful:
a. It allow mosquito to breed and spread diseases
b. it will release harmful green house gases that pollute air we breadth
c. It will degrade the soil fertility
d. it will pollute water and not only effect marine life but also reduce percolation rate of soil
6. The advantages of water stored in the ground are many. It does not evaporate, but spreads out to recharge wells and provides moisture for vegetation over a wide area. In addition, it does not provide breeding grounds for mosquitoes like stagnant water collected in ponds or artificial lakes. The ground-water is also relatively protected from contamination by human and animal waste.
7. A series of carbon compounds in which the same functional group substitutes for hydrogen in a carbon chain is called a homologous series.
C3H6,C4H8,C5H10 – Alkene
8. Test first: Take two test tubes A and B and place about 1 g of sodium carbonate in them. Pour alcohol in test tube A and carboxylic acid in test tube B. Shake the contents of the test tubes.
The test tube in which a brisk effervescence takes place, with the liberation of a colourless gas (CO2) is carboxylic acid. The test tube in which no reaction takes place is alcohol.
2nd test: , if you add a small piece of Na metal into a test tube containing alcohol, you get to see the formation ofbubbles. This is due to the release of a gas which we call as hydrogen. Carboxylic acid remains unsuccessful to show this test.
9. a. Group 2. b. Be c. Ca
10. Atomic no. 16
Electronic configuration = 2,8,6
Period = no of shell = 3 = 3rd period
Group = valance electrone = 6 + 10 = 16th group as 10 element short in 3rd period
Valency = 8 – 6 = 2
1. It involves no formation and fusion of gametes. 2. It is uniparental 3. Reproductive units are somatic cells of parent
1. It involves formation and fusion of gametes. 2. It is generally biparental. 3. Reproductive units are germ cells of parent.
12. Four point of significance of reproductive health in society
(i) Birth control methods and family planning measures
(ii) Sexually transmitted diseases and their methods of prevention.
(iii) . Importance of breast feeding and post natal care for the mother and baby.
(iv) Equality among sexes and given fair opportunities for male and female children
The reproductive health has tremendously improved in India in the last 50 years. The areas of improvement are as follows
(i) Massive child immunization programme, which has lead to a decrease in the infant mortality rate
(ii) Maternal and infant mortality rate, which has been decreased drastically due to better post natal care
(iii) Family planning, which has motivated people to have smaller families
(iv) Use of contraceptive, which has resulted in a decrease in the rate of sexually transmitted diseases and unwanted pregnancies
13. Chromosomes are thread like structure made up of DNA and proteins. They are present inside the nucleus.
Gamete formation is the first step in sexual reproduction. Number of chromosomes is halved during gamete formation. As a result, the number of chromosomes in gamete is half the number of chromosomes in somatic cells. When male and female gametes fuse during fertilization, the number of chromosomes becomes equal to that in somatic cells. In this way number of chromosomes is maintained in the progeny.
a) The colour of the flower in the F1 generation would be blue as gene for blue colour is dominant over white.
b) The percentage of white flowers in the F2 generation would be 25%.
c) The ratio of BB: Bb would be 1:2 i.e 1 BB and 2 Bb
15. a. Speciation is the process in which one or more species arise from previously existing species. A single species may give rise to a new species or two different species may give rise to a new species.
b. Natural selection: It is a basic mechanism of evolution in which nature selects the characteristics of an organism. If the behavior of a certain organism is approved by nature, the organism will survive or else will die, hence not selected by nature.
16. When a beam of light strikes fine particles get reflected in different direction by these particles is called the scattering of light .
When sunlight passes through the atmosphere, the fine particles in air scatter the blue colour (shorter wavelengths) more strongly than red. The scattered blue light enters our eyes. thus clear sky appear blue.
During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.
17. Convex mirror
Convex mirrors are commonly used as rear-view (wing) mirrors in vehicles. Convex mirrors are preferred because they always give an erect, though diminished, image. Also, they have a wider field of view as they are curved outwards. Thus, convex mirrors enable the driver to view much larger area than would be possible with a plane mirror.
18. All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem.
Biotic and Non biotic Component.
An aquarium needs to clean regularly due to lack of decomposers that can clean naturally by decomposing organic substance.
19. Fossils may be defined as the remains of the organisms which have been preserved in the form of molds or cast in rocks etc. since prehistoric ages. When a plant or an animals dies, their remains falls on the ground.
Over a period of time their body gets covered by sediments brought by rivers, winds etc. These sediments keeps on getting accumulated for over hundred of years and when that land gets eroded, the fossils can be seen Thus, the process of accumulation of dead remains of plants and animals for over hundreds of years results in the formation of fossils.
The age of the fossils can be determined by the following way:
1) Radiometric dating:
In this method, the age of the fossil can be determined by tracing the radioactive elements present in the rocks and examining it chemically.
2) Relative dating:
The fossils are found in the sedimentary rocks in the form of layers accumulated over large span of time. So, using this fact, the geologist find the age of fossils in the way that the fossil found at the bottom of those layers are found to be older than that found above those.
Analysis of the organ structure in fossils allows us to make estimates of how far back evolutionary relationships go.
X Summative Assessment -1(2014-15) English Communicative Question Paper
X Summative Assessment -1(2014-15) English Communicative Question Paper
10th English original question paper CBSE Board 2014-15 Download as Pdf.
The CBSE Class 12th Mathematics Question Paper Solution 2014 has been prepared by the top faculties of CBSE Board School Teacher and by many famous Coaching Institutes faculties is coming soon
Solved Physics and Chemistry Question Paper 2014 CBSE Board Class XII
Solution Board Examinations 2013 Class-XII English (Core)Code : 1/2
CBSE-XII-2014 CBSE Board
CHEMISTRY Paper & Solution Code : 56/3
Time : 3 Hrs. Max. Marks : 70
General Instructions :
(i) All questions are compulsory.
(ii) Questions number 1 to 8 are very short answer questions and carry 1 mark each.
(iii) Questions 9 to 18 are short answer questions and carry 2 marks each.
(iv) Question number 19 to 27 are also short-answer questions and carry 3 marks each.
(v) Question number 28 to 30 are long-answer questions and carry 5 marks each.
(vi) Use Log Tables, if necessary. Use of calculators is not allowed
Physics Paper & Solution Code : 55/3
Time : 3 Hrs. Max. Marks : 70
General Instruction :
(i) All questions are compulsory.
(ii) There are 30 questions in total. Questions 1 to 8 are very short answer type questions and carry one mark each.
(iii) Questions 9 to 18 carry two marks each, questions 19 to 27 carry three marks each and questions 28 to 30 carry five marks each.
(iv) One of the questions carrying three marks weightage is value based question
(v) There is not overall choice.
However, an internal choice has been provided in one question of two marks, one question of three marks and all three question of five marks each weightage. You have to attempt only one of the choices in such question
Courtesy: Career Point
Class-XIISubject- English (Core)
Read the passage carefully and answer the questions that follow : 12
1. Too many parents these days can't say no. As a result, they find themselves raising children who respond
greedily to the advertisements aimed right at them. Even getting what they want doesn't satisfy some kids; they only want more. Now, a growing number of psychologists, educators and parents think it's time to stop
the madness and start teaching kids about what's really important : values like hard work, contentment, honesty and compassion. The struggle to set limits has never been tougher - and the stakes have never been higher. One recent study of adults who were overindulged as children, paints a discouraging picture of their
future : when given too much too soon, they grow up to be adults who have difficulty coping with life's disappointments. They also have a distorted sense of entitlement that gets in the way of success in the workplace and in relationships.
Courtesy: Career Point
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