Central Institute of Higher Tibetan Studies 2009 CBSE CLASS X - Question Paper

7. ques. 11 to 14 in part A and 25 to 26 in part B are also short ans kind
ques. and carry 3 marks every.
8. ques. 15 and 16 in part A and ques. 27 in part B are long ans kind
ques. and carry 5 marks every.
part A
1. A ray of light LM is incident on a mirror as shown in the figure. The angle of incidence for
this ray is the angle ranging from it and the line joining 2 other points in the figure. Name
these 2 points.
2. Metals generally occur in solid state. Name and write symbol of a metal that exists in
liquid state at room temperature.
3. During summer season, a milkman usually adds a very small amount of baking soda to
fresh milk. provide 1 cause.
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4. The subsequent table provide the values of refractive indices of a few media.
S.No. one two three four 5
Medium Water Crown Glass Rock salt Ruby Diamond
Refractive 1.33 1.52 1.54 1.71 2.42
Index
Use this table to provide an example of (i) a medium pair so that light speeds up when it goes
from 1 of these media to a different. (ii) a medium pair so that light slows down when it
goes from 1 of these media to a different.
5. Why potato chips manufacturers fill the packet of chips with nitrogen gas?
6. Alloys are used in electrical heating devices rather than pure metals. provide 1 cause.
7. Tooth enamel is 1 of the hardest substances in our body. How does it undergo damage
due to eating chocolates and sweets? What should we do to prevent it?
8. A learner has been collecting silver coins and copper coins. 1 day she observed a
black coating on silver coins and a green coating on copper coins. Which chemical
phenomenon is responsible for these coatings? Write the chemical name of black and
green coatings.
9. 2 students perform the experiments on series and parallel combinations of 2 provided
resistors R1 and R2 and plot the subsequent V-I graphs.
Which of the graphs is (are) correctly labelled in terms of the words ‘series’ and parallel’
Justify your ans.
10. Draw the trend of magnetic field lines of a current carrying solenoid. What does the
trend of field lines inside the solenoid indicate? Write 1 application of magnetic field
of current carrying solenoid.
11. A learner obtains the writing on the blackboard as blurred and unclear when sitting on the
last desk in the classroom. He however, sees it clearly when sitting on the front desk at an

Earning:   Approval pending.