Science Preliminary Paper

Q1. (A) Solve the following:             7 Marks
1.      The element eka – aluminum in Mendeleev’s periodic table is known as ______ in modern periodic table.
2.      Phenolphthalein is _________ type of indicator.
3.      1 kilowatt hr = ____________ Joules.
a.       4.6 x 106 Joule
b.      3.6 x 106 Joule
c.       30.6 x 106 Joule
d.      3.6 x 105 Joule
Q1. B. Match the columns.
Column I
Column II
1.      Sodium
2.      Cerium
3.      Sulphur
4.      Manganese

a.       Lanthanide
b.      Metalloid
c.       Transition metal
d.      Noble metal
e.       Metal
f.       Non – metal.
Q2. Answer the following sub questions:    6  marks
1.      The material used for fuse has low melting point.
2.       Fleming’s right hand rule
3.      What is ray diagram? What are the rules used for drawing ray diagrams for the formation of image by spherical mirror?
Q3. Answer Any Four of the following questions: 12 marks
1.      What are the demerits of Mendeleev’s periodic table?
2.      Write short notes on Indicators (with proper example).
3.      State application (uses) of baking soda.
4.      State the characteristics of magnetic lines of force.
5.      Applications of spherical mirrors and lenses:
Q4. Answer any one of the following questions:    5 marks
                        1. Explain how the formation of rainbow occurs.
                       2. Find the expression for the resistors connected in series and parallel.
Q5. (A) Fill in the blanks:                 3 marks                     
1.      The direction of the magnetic field around a straight conductor carrying current is given by ____________
a.       Right hand thumb rule   b. Fleming’s left hand rule  
b.      c. Fleming’s right hand rule   d.  None of these.
2.      An optical device used by watch repairers is _____________.
3.      The organic compounds having double or triple bond in them are termed as ___________

Q5. (B) Answer in one sentence                   4 marks
1.      Metal which forms an amphoteric oxide?
2.      An alloy of copper and zinc.
3.      A compound which is added to lower the fusion temperature of an electrolytic bath in extraction of aluminium.
4.      A common ore of aluminium.
Q6 . (A) Give scientific reasons:       4 marks
1.      Gold and silver are used to make jewellery.
2. The plants are kept in dark before determining the factors essential for photosynthesis.
Q6. (B) Distinguish between : 2 marks
Voluntary and Involuntary movements
Q7. Answer any four of the following questions: 12 marks
1.      Write a short note on Reflex action
2.      Describe sexual reproduction in plants.
3.      With the help of a diagram (Punnett square) show a Mendelian experiment where tall pea plant bearing red flowers is crossed with a short pea plant bearing white flowers. Write both the phenotypic and genotypic ration for F2 generation.
4.      State and explain how alkanes are further classified.
5.      Explain the structure and function of a nephron.

Q8. Answer in detail (Any one)        5 marks
1. In the extraction of aluminium write the following.
                                                        i.            Name the process of concentration of Bauxite.
                                                      ii.            Write the cathode reaction in electrolytic reduction of alumina.
                                                    iii.            Write the function and formula of cryolite in the extraction of aluminium.
                                                    iv.            Write an equation for the action of heat on aluminium hydroxide.
                                                      v.            Draw the diagram of extraction of aluminium.
                                                    vi.            Why is it necessary to replace anodes time to time?
                                                  vii.            What happens when aluminium ore is heated with concentrated caustic soda. Write the balanced chemical equation for the same.

2. Explain the formation of an ionic compound between metal and a non – metal by transfer of electrons with Mg as the metal and Cl as a non – metal to illustrate your answer.

=============All the best==============

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