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Why structural isomerism is not possible for propane?

Posted by gaurav deokar (Feb 22, 2017 12:43 p.m.) (Question ID: 2442)

 If fand f2 are focal length of two lens,what is the relation for equivalent focal length?

Posted by Ranveer Raj (Feb 21, 2017 11:30 p.m.) (Question ID: 2423)

If angle of incidence=90, then angle of refraction=?

Posted by Ranveer Raj (Feb 21, 2017 11:24 p.m.) (Question ID: 2422)

  • Answers:
  • To answer this, one must know the mediums of incidence & refraction. then the below formula can be used:

    <i>n1 * sin A = n2 * sin B</i>

    where A is the angle of Incidence & B is the angle of Refration. Also, n1 is the index of refraction for the material the incident light ray is traveling through, and n2 is the index of refraction for the material the refracted light ray is traveling through.

    Answered by Manish Gandhi (Feb 22, 2017 12:38 p.m.)
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Acc. To snells law- n21 xn12=?

Posted by Ranveer Raj (Feb 21, 2017 11:21 p.m.) (Question ID: 2421)

  • Answers:
  • Acc. To snells law- n21 xn12= 1 (Answer)

    Answered by Manish Gandhi (Feb 22, 2017 12:39 p.m.)
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Formula of vinyl chloride?

Posted by Ranveer Raj (Feb 21, 2017 11:17 p.m.) (Question ID: 2420)

  • Answers:
  • And. C2H3Cl

     

    Answered by Naveen Sharma (Feb 22, 2017 8:43 a.m.)
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Homologous organ ?

Posted by Ranveer Raj (Feb 21, 2017 10:18 p.m.) (Question ID: 2417)

  • Answers:
  • The organs which perform different functions in different species but have similar basic structure and similar embryonic origin are called homologous organs.

    For eg -  1. Forelimbs of frog, lizard, humans, birds,  etc. 

    2. Radish and carrot 

     

    Answered by Shruti Sharma (Feb 22, 2017 1:29 p.m.)
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  • The arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale are homologous structures. They are different and have a different purpose, but they are similar and share common traits.

    Answered by Shweta Gulati (Feb 21, 2017 10:25 p.m.)
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What is a covalent bond?

Posted by Ranveer Raj (Feb 21, 2017 10:14 p.m.) (Question ID: 2416)

  • Answers:
  • The sharing of electrons by an atom to complete its electronic configuration leads to the formation of covalent bonds. Example carbon forms covalent bonds.

    Answered by Shweta Gulati (Feb 21, 2017 10:27 p.m.)
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A circuit has fuse of 5A. What us the maximum number of 100W bulbs that can be safely used in circuit? 

Posted by Krishna Sinha (Feb 21, 2017 6:53 p.m.) (Question ID: 2404)

  • Answers:
  • Suppose x number of such bulbs can be used 

    Power of one bulb = 100 watt 

    Power of x bulbs (p) = 100 X x watts 

    Potential difference (V) = 220 volts 

    I = 5 ampere 

    We know that P = VI 

    100 X x = 220 x 5 

    x = 220 x 5 /100 = 11 bulbs.

    Answered by Shweta Gulati (Feb 21, 2017 7:43 p.m.)
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Blind spot

 

Posted by Sandeep Kumar (Feb 20, 2017 8:18 p.m.) (Question ID: 2369)

  • Please give some reference!!

    Posted by JD Shukla (Feb 20, 2017 9:07 p.m.)
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  • Answers:
  • Ans.The blind spot is the area on the retina without receptors that respond to light. Therefore an image that falls on this region will NOT be seen. It is in this region that the optic nerve exits the eye on its way to the brain.

    Answered by Naveen Sharma (Feb 20, 2017 9:31 p.m.)
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A three times magnified image of a candle flame is to be projected on a wall which type of lens required for this purpose if the candle is at a distance of 6m from the wall calculate the focal length of the lens

 

Posted by Simran Singhania (Feb 20, 2017 4:54 p.m.) (Question ID: 2363)

  • Answers:
  • m = v/u

    3 = 6/u

    u = 2

    By lens formula

    1/u - 1/v = 1/f

    1/2 - 1/6 = 1/f 

    3 - 2/6 = 1/f

    1/6 = 1/f 

    f = 6 cm

    Answered by Shagun Vishwakarma (Feb 20, 2017 7:22 p.m.)
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Which enzyme helps in breaking surcose into glucose and fructose?

Posted by Sarthak Chauhan (Feb 19, 2017 6:56 p.m.) (Question ID: 2337)

  • Answers:
  • The enzyme sucrase digests sucrose or table sugar into its constituent units of glucose and fructose, while lactase breaks lactose or milk sugar into glucose and galactose. These monosaccharides are absorbed in the small intestine and transported to the liver through blood.

    Answered by Shweta Gulati (Feb 20, 2017 1:06 a.m.)
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  • Invertase

    Answered by sunny dhankhar (Feb 19, 2017 10:02 p.m.)
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Q)What is the difference between regeneration and fragmentation?

 

Posted by PRANTIK SAHA (Feb 19, 2017 2:01 p.m.) (Question ID: 2331)

  • Answers:
  • Fragmentation

    Regeneration

    1. Fragmentation occurs in multi-cellular organisms with simple body organisation.

    1. Regeneration occurs in fully differentiated multi-cellular organisms with complex body organization.

    2. In fragmentation, an organism breaks into pieces and each piece develops into new individual.

    2. In regeneration organisms if breaks into pieces, each piece may or may not develop into new individual.

    3. No specialised cells are involved in fragmentation.

    3. In regeneration, specialised cells proliferate and form a mass of cells. The cells from the mass differentiate to form different cells types and tissues.

    Example: Spirogyra

    Example: Regeneration of blood cells in mammals.

    Answered by Sarthak Chauhan (Feb 19, 2017 6:40 p.m.)
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Coal on burning prodces heat and energy but when we eat it then we dont get energy,but we eat an apple then we will get energy.why?

Posted by Piyush Dubey (Feb 19, 2017 7:14 a.m.) (Question ID: 2315)

  • Answers:
  • Because our bile is not so strong that it can digest coal and get energy from it. Also coal has no glucose and we take glucose as energy.

    Answered by Vishu Tomar (Feb 19, 2017 10:03 a.m.)
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why human eye is able to see the 3d objects ?

Posted by Abhishek Kapoor (Feb 18, 2017 7:08 p.m.) (Question ID: 2298)

  • Answers:
  • Human eye is able to see the 3-D objets due to double eyes that can see objects with two differnet angles.

    Answered by RAJENDRA SINGH (Feb 18, 2017 9:25 p.m.)
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why rainbow is curve?

Posted by Abhishek Kapoor (Feb 18, 2017 7:07 p.m.) (Question ID: 2297)

  • Answers:
  • Rainbow is curved as horizon appears curved and dispesed light enters the eyes after total internal reflection.

    Answered by RAJENDRA SINGH (Feb 18, 2017 9:29 p.m.)
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what is a molten state of a metal

Posted by yuvaraj kumar (Feb 17, 2017 7:10 p.m.) (Question ID: 2258)

A three times magnified image of a candle is to be projected on a wall. Name the type of lens required for this purpose. If the candle is at a distance of 6 m from the wall .calculate the focal length of lens

Posted by Simran Singhania (Feb 17, 2017 5:01 p.m.) (Question ID: 2246)

  • Answers:
  •  

    You can refer this image for your answer!

    Answered by Shweta Gulati (Feb 18, 2017 11:34 a.m.)
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The absolute refractive indices of glass and water are 4/3 and 3/2, respectively. If the speed of light in glass is 2×10m/s, calculate the speed of light in vaccum and water.

Posted by Snehal Panchal (Feb 17, 2017 3:29 p.m.) (Question ID: 2242)

  • Answers:
  • You have written the wrong question as refractive index of glass is 3/2 and water 4/3.

     ng = 3/2 and nw = 4/3.

    Absolute Refractive Index of a medium = Speed of light in vacuum/Speed of light in the medium

    Speed of light in glass = 2 x 108 m/s
    Speed of Light in Vacuum = (3/2) x 2 x 108 m/s = 3 x 108 m/s

    Speed of light in water = (3 x 108m/s)/(4/3)
                                            = 2.25 x 108 m/s

    Answered by Shweta Gulati (Feb 18, 2017 11:38 a.m.)
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If due to some disease or injury the cornea of an eye is clouded the vision is impaired and the person may became blind this type of blindness may be cured by replacing the defective cornea with the cornea of the donated eye.Suggest some measure for motivating people to donate their eye after death.

Posted by Kundan Kumar (Feb 17, 2017 2:25 p.m.) (Question ID: 2237)

  • Answers:
  • Ans. The measures that we can adopt to motivate people for eye donation are followin :

    • Campaigning needs to be done on eye donation.
    • Posters containing motivating quotes should be placed at appropriate locations.
    • Help can be taken from media sources like television, newspapers etc for creating awareness about eye donation.
    • Various positive aspects of eye donation should be explained through counselling.
    Answered by Naveen Sharma (Feb 17, 2017 2:34 p.m.)
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Explain Double Fertilisation in plants?

Posted by Jayaram Shetty (Feb 17, 2017 12:34 p.m.) (Question ID: 2233)

  • Answers:
  • Ans. Double fertilization is a complex mechanism of flowering plants angiosperms. This process involves the joining of a female gametophyte (embryo sac) with two male gametes (sperm). It begins when a pollen grain adheres to the stigma of the carpel the female reproductive structure of a flower. The pollen grain then takes in moisture and begins to germinate, forming a pollen tube that extends down toward the ovary through the style. The tip of the pollen tube then enters the ovary and penetrates through the micropyle opening in the ovule. The pollen tube proceeds to release the two sperm in the embryo sac.

    One sperm fertilizes the egg cell and the other sperm combines with the two polar nuclei of the large central cell of the embryo sac. The haploid sperm and haploid egg combine to form a diploid zygote, while the other sperm and the two haploid polar nuclei of the large central cell of the embryo sac form a triploid nucleus (triple fusion).

    Answered by Naveen Sharma (Feb 17, 2017 2:04 p.m.)
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Explain Ganga action plan

Posted by Pankaj Bhandari (Feb 16, 2017 8:33 p.m.) (Question ID: 2216)

  • Answers:
  • <h3 align="center" style="margin:8px 0px">GANGA ACTION PLAN</h3>

    The Ganga action plan was, launched by Shri Rajeev Gandhi, the then Prime Minister of India on 14 Jan. 1986 with the main objective of pollution abatement, to improve the water quality by Interception, Diversion and treatment of domestic sewage and present toxic and industrial chemical wastes from identified grossly polluting units entering in to the river. The other objectives of the Ganga Action Plan are as under.

    • Control of non-point pollution from agricultural run off, human defecation, cattle wallowing and throwing of unburnt and half burnt bodies into the river.

    • Research and Development to conserve the biotic, diversity of the river to augment its productivity.

    • New technology of sewage treatment like Up-flow Anaerobic Sludge Blanket (UASB) and sewage treatment through afforestation has been successfully developed.

    • Rehabilitation of soft-shelled turtles for pollution abatement of river have been demonstrated and found useful.

    • Resource recovery options like production of methane for energy generation and use of aquaculture for revenue generation have been demonstrated.

    • To act as trend setter for taking up similar action plans in other grossly polluted stretches in other rivers.

    The ultimate objective of the GAP is to have an approach of integrated river basin management considering the various dynamic inter-actions between abiotic and biotic eco-system.

    Answered by Shweta Gulati (Feb 17, 2017 12:28 a.m.)
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Difference between transparent and translucent medium.

(i)Real image and virtual image

Posted by RITESH SAHANI (Feb 16, 2017 7:58 p.m.) (Question ID: 2211)

  • Answers:
  • (a) In the field of optics, transparency  is the physical property of allowing light to pass through a material without being scattered. so, the medium showing the property of transparency are called transparent mediums . A transparent medium not only allows the transport of light but allows the image formation. eg Clear glass

    A translucent medium only allows the transport of light. The light may pass through the material but the image formation on the other side is not visible. eg Frosted glass

    (b) The image that can be obtained on a sceen is called real image. It is always inverted. The most common example is image formed in a cinema hall.

     The image that cannot be obtained on a screen is called virtual image.It may be erect or inverted. The image formed in a plane mirror is virtual.

     

    Answered by Shweta Gulati (Feb 17, 2017 12:39 a.m.)
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Difference between reflection and total internal reflection

Posted by RITESH SAHANI (Feb 16, 2017 7:54 p.m.) (Question ID: 2210)

  • Answers:
  • Ans.

    • Reflection and total internal reflection are physical properties of waves. Reflection occurs in all kind of waves, but total internal reflection occurs only with light rays.
    • Total internal reflection occurs when light passes through denser medium to the lighter medium. But for reflection there is no such restriction to consider.
    • In reflection of a wave, both reflection and refraction (passing through second medium) waves occur. But in total internal reflection, only reflection ray is occurs.
    Answered by Naveen Sharma (Feb 16, 2017 8:17 p.m.)
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what are the diffetent ways in which we can trace evolution relationships

Posted by sanjay pandey (Feb 16, 2017 9:17 a.m.) (Question ID: 2189)

  • Answers:
  • Over thousands and millions of years, a bewildering variety of species has evolved on the earth. Among these, some are known and some are unknown to us. Characteristics assist us to trace the evolutionary relationship between organisms. Evolutionary relationships help us to trace who we are more close to and who is our common ancestor.

    1)The homologous and analogous characteristics help to trace an evolutionary relationship between different species.

    2)We use living species to trace evolutionary relationships. But organisms which once lived and do not exist anymore also have a story to tell about evolution.  They can be used for tracing the evolutionary relationship between species. Fossils are one of the examples.

    Answered by Shweta Gulati (Feb 16, 2017 10:41 a.m.)
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What is speciation? 

 

Posted by Avinash Shukla (Feb 16, 2017 6:43 a.m.) (Question ID: 2184)

  • Answers:
  • Origin of new species from the pre existing one

    Answered by Aravamudhan S (Feb 16, 2017 7:08 a.m.)
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explain the mechanism of heridity??

Posted by Navneeth Nagesh (Feb 15, 2017 10:49 p.m.) (Question ID: 2174)

what is excavating?

Posted by Mathew Samuel (Feb 15, 2017 9:09 p.m.) (Question ID: 2168)

  • Answers:
  • In archaeology, excavation is the exposure, processing and recording of archaeological remains. An excavation site or "dig" is a site being studied. Excavation involves the recovery of several types of data from a site. 

    Answered by Shweta Gulati (Feb 15, 2017 10:30 p.m.)
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Explain phenotypic and genotypic ratio

Posted by Saurabh Gehlot (Feb 14, 2017 8:56 p.m.) (Question ID: 2119)

  • Answers:
  • Phenotypic ratio is the ratio of traits visible to us in an organism physically..Genotypic ratio is the ratio of traits inherited in an organism genetically..

    For eg-In a generation four plants are produced (TT), (Tt), (Tt), (tt) 

    In this case 3 will appear tall to us and one dwarf thus phenotypic ratio is 3:4

    But if you see genetically 1 plant is pure tall and two are hybrid tall and one is pure dwarf thus genotypic ratio is 1:2:1

    Answered by ashita singh (Feb 15, 2017 11:17 a.m.)
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Define homologous series

Posted by Shubham Chakraborty (Feb 14, 2017 7:57 p.m.) (Question ID: 2117)

  • Answers:
  • A homologous series is a group of compounds in which their functional group are same and the chemical properties of the compound were similar in which the successive compounds differ by CH2 group.

    Answered by Kundan Kumar (Feb 17, 2017 2:29 p.m.)
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  • It is a series of similiarly constituted compounds that have similiar chemical properties and same funtional group

    Answered by Saurabh Gehlot (Feb 14, 2017 8:58 p.m.)
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  • Homologous series is a group or a family of hydrocarbons in which the difference between any two successive members is a CH group or 14u mass. 

    All members of a homologous series have the same functional group and thus possess similar chemical properties. 

    Answered by Shruti Sharma (Feb 14, 2017 8:02 p.m.)
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what is double fertilisation 

Posted by Raj Kumar (Feb 14, 2017 6:34 p.m.) (Question ID: 2116)

  • Answers:
  • The pollen grain produces a pollen tube which grows through the style and reaches the ovary. In the ovary, it enters an ovule through its micropyle. It ruptures the nucellus and enters the embryo sac. 

    In the embryo sac, the pollen tube ruptures and discharges two male gametes. 

    One of the two male gametes fuses with the egg cell to form the zygote. This process is called syngamy. 

    The other male gametes fuses with the secondary nucleus (also called polar nuclei) to form a primary endorsers nucleus. This process is called triple fusion since three nuclei get fused.

    Syngamy and triple fusion together are called double fertilisation. 

     

    Answered by Shruti Sharma (Feb 14, 2017 7:57 p.m.)
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  • The process involving the joining of a female gametophyte with two male gametes is called double fertilization.

    Answered by K R Madhusudana (Feb 14, 2017 7:55 p.m.)
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