Monday, 14 August 2017

CLASS X GENERAL QUESTION science


Question Paper for general practice
SCIENCE (THEORY)
Time: 3 hrs                                                                                                                                              Max.marks: 80
General Instructions:
i)                     The question paper comprises of two sections, A and B. You are to attempt both the sections.
ii)                    All questions are compulsory.
iii)                   There is no over all choice. However, internal choice has been provided in all the three question of five marks category. Only one option in such question in to be attempted.
iv)                   All questions of section A and all questions of section B are to be attempted separately.
v)                    Question numbers 1 to 4 in section A are one mark questions. There are to be answered in one word or one sentence.
vi)                   Question numbers 5 to 13 are two mark questions, to be answered in about 30 words each.
vii)                  Question numbers 14 to 22 are three mark questions, to be answered in about 50 words each.
viii)                 Question numbers 23 to 25 are five mark questions, to be answered in about 70 words each.
ix)                   Question numbers 26 to 41 in section B are multiple choice questions based on practical skills. Each question is a one mark question. You are to select one most appropriate response out of the four provided to you.

SECTION – A
1.        What are the 3 R’s to save the environment?
2.        Define 1 dioptre of power of a lens.
3.        Name  two unisexual flower.
4.        Draw the electron dot structure of C2H6.
5.        Why is a normal eye not able to see clearly the objects placed closer than 25 cm?
6.        Name two other elements which are in the same family as (i) carbon (ii) sodium.
7.        What do you mean by STD? Name one STD each caused by bacteria &  virus.
8.        Give  any two ways in which biodegradable  substances would affect the environment.
9.        Why do stars twinkle?
10.     What do you mean by acquired traits & inherited traits?
11.     How would you bring about the change (i) ethanol to ethene (ii) propanol to propanoic acid?
12.     Define magnification of a spherical mirror. What will be the magnification in case of a plane mirror?
13.     What are fossils? What do they tell us about the process of evolution?
14.     Why should we conserve forests and wild life?
15.     The near point of a hypermetropic person is 50 cm. What should be the focal length and power of the lens used by him if he wants to read a newspaper placed 20 cm away?
16.     Explain double fertilisation in flowering plants.
17.     What is esterification? Write the reaction involved. Write one use of ester.
18.     Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3x 108 m/sec.
19.     In human beings blue eye colour is recessive to brown eye colour. A brown eyed man has a blue eyed mother.
(a)     What is the genotype of man & his mother?
(b)     What are possible genotypes of his father/
(c)      If the man marries a blue eyed woman, what are the possible genotypes of their offspring?
20.     (a)           Why does carbon form compounds mainly by covalent bonding?
(b)           List any two reasons for carbon forming a very large number of compounds.
     21.      (a)           What is scattering of light?                                                                                      
(b)           Explain why does dangerous signals are made up of red or orange colours?      (1+2)
     22.      Answer  the following:                                                                             (1/2 X 6=3)
                (i)             Who proposed the theory of Inheritance of Acquired Characters/
                (ii)            Who first suggested that ‘organisms never originate spontaneously from non Living’?
                (iii)           Who wrote the book “Origin of species”?
                (iv)           What is the process of gradual change from simple to complex organisms?
                (v)            What is sudden inheritable change called as?
                (vi)           What the technical term for the resemblance of colour of animals with surrounding environment?
23.           Draw a diagram to show that formation if image of a distance object of myopic eye.
                How can this defect be rectified? State two reasons due to which this  defect may be caused?
                                                                OR,
                What is hypermetropia? Draw a ray diagram to show the image formation of an object by: (i) Hypermetropia eye
   (ii) Correction made with suitable lens.
24.           (a) How does the creation of variations in a species promote survival?
(b) How is the sex of a child determined in human beings?
                                                                                OR,
Explain the terms:
(a)     Homologous organs with examples.
(b)     Analogous organs with examples.
(c)      Genotype
(d)     Phenotype
(e)     Genetic drift
25.           An element is placed in second group and third period of the periodic table, burns in presence of oxygen to form a basic oxide.
                (a) Identify the element.
                (b) Write the electronic configuration.
                © Write the balanced equation when it burns in the presence of air.
(d)     Write the balanced equation when this oxide is dissolved in water.
(e)     What will be the nature of the solution thus obtained.

OR,
                Atomic number of a few elements is given below:
                10, 20, 7, 14.
(a)     Identify the elements.
(b)     Identify the group number of these elements in the periodic table.
(c)      Identify the periods of these elements in the periodic table.
(d)     What would be the electronic configuration for each of these elements?
(e)     Determine the valency of these elements.


SECTION – B
26.           According to Snell’s law:
                (a)           < i = < r    (b)           sin i  α sin r
                ©             sin i α 1/sin r            (d)           sin i = µsin r
27.           A ray falls normally on a surface, it will :
                (a)           Bends inwards                         (b)           bends outwards
                ©             pass straight                            (d)           retrace back.
28.           A ray goes from an optically denser to an optically rarer medium, it ;
                (a)           passes straight                        (b)           bends towards normal
                ©             bends away from normal         (d)           will go parallel to incident ray
29.           divergent lens is :
                (a)           of uniform thickness                 (b)           thicker at centre , thinner at edges
                ( c)           have positive focal length         (d)           thicker at edges, thinner at centre            
30.           Lateral displacement suffered in a slab of thickness is:
                (a)           α 1/t                                         (b)           α 1/t2
                ( c)           α t2                                                                (d)           α t
31.           What happens when copper is added to zinc sulphate solution?
                ( a)          the solution becomes colourless and zinc metal gets deposited
                ( b)          no reaction takes place as copper is less reactive than zinc
                ( c)           no reaction takes place as copper is more reactive than zinc
                ( d)          the solution remains blue and zinc metal gets deposited.
32.           Can we store copper sulphate in iron container and why?
                ( a )         no, because iron is more reactive than copper, therefore reaction will take place.
                (b)           No, because copper is more reactive than iron
                (c )           yes, because copper is more reactive than iron
                (d)           yes, because copper is less reactive than iron.
33.           When sodium carbonate is added to acetic acid, CO2 is produced. The other product of  the reaction is /are:
                (a)           sodium acetate & water           (b)           water only
                ( c)           sodium acetate only                 (d)           none of these
34.           Vinegar is :
                (a) 5 - 8 % acetic acid                                             (b)           acetic acid of any concentration
                (c)            100% acetic acid                     (d)           50% acetic acid
35.           Acetic acid and water are mixed in a test tube, the resultant solution will be:
                (a)           clear solution                                           (b)           turbid solution
                ( c)           acid forms lower layer             (d)           water forms lower layer
36.           Budding involves growth of new organisms:
                (a)           outside the parent body           (b)           on the parent body
                ( c)           inside the parent body                             (d)           both (a) & (c)
37.           Which of the following is not a mode of asexual reproduction?
                (a)           Multiple fission                         (b)           binary fission
                ( c)           spore formation                       (d)           conjugation
38.           Multiple fission  occurs in :
                (a)           Euglena                                   (b)           Yeast
                ( c)           Plasmodium                                             (d)           Paramecium
39.           Clones are the individuals which are produced by:
                (a) Asexual reproduction         (b)           sexual reproduction
                ( c )          Both of these                           (d) None of these
40.           In Yeast budding takes place by the following steps:
                (i)             The bud may become separate from the parental body and develop into a new individual
                (ii)            Thus they may form a colony
                (iii)           A bud comes out in any direction from the parental cell
                (iv)           The body bud develops and give rise to another baby bud
The proper sequence of steps is:
(a)     (iii), (i), (iv), (ii)
(b)     (i), (ii), (iii), (iv)
(c)      (iii), (ii), (i), (iv)
(d)     (ii), (iii), (iv), (i)
41.           The shape of amoeba is :
                (a)           round                       (b)           oval          ( c)           irregular   (d)           rod like
               

MARKING SCHEME
1.        Reduce, recycle, reuse.                                                                                                                           1
2.        A lens of focal length 1m.                                                                                                        1
3.        Papaya & watermelon flowers                                                                                 ½ + ½
4.        NCERT Fig.No. 4.6                                                                                                                                 1             
5.        Because ciliary muscles cannot contract beyond a certain limit.                                              2
6.        (i) carbon- silicon, Germanium.                                                                                               1+1
(ii) sodium-lithium, potassium.                                                                                
7.        Sexually transmitted disease. (i) Gonorrhoea/Syphilis. (ii) warts /Aids                     1+1
8.        (i) It converts wastes into CO 2 .
(ii) Increase in the number of micro-organism that gives unhealthy environment.1+1
9.        Due to atmospheric refraction of light or apparent change in the position of the stars.2
10.     Inherited: Which run in the family/transmitted from parents to progeny.
 Acquired: Acquired In the life time of an individual                                                  1+1
11.     (a)           CH3CH2OH        —› CH2=CH2 + H2O
(b)           CH3CH2 CH2OH        —›    CH3CH2COOH                                                             1+1
12.           Magnification, m= size of image/size of object
                For plane mirror, m= +1                                                                                                          1½ +1/2 
13.     Fossils/ remains of dead organisms of the past
It tells us about their existence on the earth.                                                           1+1
14.     Forests provide food, medicine, fire wood, maintain balance of gas, water & prevent flood and soil erosion.
Wildlife helps in maintaining Food Chain, provide wool, bones, skins etc.               1 1/2x 2
15.          u= -20 cm, v = - 50 cm, f =?
Lens formula
1/f = 1/v – 1/u
Put the value, f = 100/3 = 33.3 cm
P = + 3D
Lens -à converging/convex                                                                                   1+1+1
16.     Double fertilization=  (i)Syngamy(One male +One female gamete/ovum) , (ii) Triple fusion(2nd male gamete + polar nuclei )                                                                                                1 ½ x 2
17.           When an acid is heated with an alcohol in the presence of conc. H2SO4 an ester is produced eg
                                                         CONC.H2SO4  
                CH3COOH +  C2H5OH                             CH3COOC2H5
                Ester is used as flavouring agent.                                                                            1+1+1
18. Refractive index n = speed of light in air(c)/speed of light in glass (v)
                                                1.5 = 3x108/v
                                                V = 3x108/1.5
                                                V = 2x108 m/s                                                                                          1+1+1
19. (a)     Genotype of man: Bb/Heterozygous; Genotype of mother: bb/homozygous recessive
                (b)           Possible genotype of father: Bb/Heterozygous or, BB/Homozygous dominant
                ©             50% blue eyed, 50% Brown eyed; 1:1/test cross                                    1+1+1
20. a) Since carbon has four valence electrons and a very large amount of energy is required to loose or gain four electrons
       b) Catenation – Self linkage ability, tetra valency, isomerism.                           2+1
21. a) When a ray of light falls on the particles of atmosphere then ray of light get scattered in all directions this is called scattering of light.
                b) The light of red colour scattered least due to its large wavelength so red colour of light passes through smoke, fog or dust and can be seen easily from distant point.    1+2
22. i)        Lamark   ii) Louis Pasteur  iii) Charles Darwin  iv) Evolution  v) Mutation  vi) Camouflage.                                                                                                                                                                     1/2 x6
23.           NCERT Fig 11.2, (b) & (c); using concave lens of suitable power; causes- (i) excessive curvature of eye lens, (ii) elongation of eye ball.                                                                            3+2
OR,
Correct definition; NCERT Fig. no. 11.3 (b) & (c).                                                  1+2+2
24. a)The useful variation in individual of a species will enable them to adapt according to the changes and new needs. Thus they will enable the survival of species.
                b) There are 23 pairs of chromosomes in which 1 pair is sex chromosomes. These sex chromosomes are again of two types i.e., ‘x’ and ‘y’ chromosomes. When a child bears 22 pairs + x + y ,it will be male and the child bearing 22 pairs of autosomes along with ‘x’ pair of sex chromosomes will be female.
Diagram-NCERT figure no.9.6                                                                                                               2+3
                                                                                Or
a)       Homologous organs-Organs of different classes having similar origins and structures but perform different functions.
b)       Analogous organs-Organs similar in functions but different in structure and origin.
c)        Genotype-Internal genetic constitutions of an organisms.
d)       Phenotype-Externally visible characters of an organisms.
e)       Genetic Drift-It is a change of gene frequency from one generation to another.     1X5
25.           a) Magnesium        
                b) 2, 8, 2
                c) 2Mg(s) + O2 (g) → 2MgO(s)
                d) MgO(s) + H2O (l) → Mg(OH)2(aq)
                e)             Alkaline/Basic                                                                                                                           1x5

26.   (d)
27.   (d)
28.   ©
29. (d)
30.   (d)
31. (b)
32.   (d)
33.   (a)
34.   (a)
35.   (a)
36.   (d)
37.   (d)
38.   ©
39.   (a)
40.   (a)

41.   ©

No comments:

Favicon..