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SCIENCE
– I
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Time : 2 ½ Hours
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MARCH – 2000
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Marks : 60
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| Q. 1. |
A) |
Four incomplete statements are given below.
Complete them by choosing the proper alternatives from those
given and rewrite the completed statements in your answer
books: |
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i) |
Valency of halogen with respect to hydrogen is
___________
a) 1 b) 2 c) 4
d) 7. |
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ii) |
_________ solution is electrolyte.
a) Sugar b) Acetic acid
c) Urea d) Glycerine. |
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iii) |
The
function of electric iron depends on _________
a) Joule’s law b) Right hand rule c)
Faraday’s law d) Ohm’s Law. |
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iv) |
Power is _________
a) Product of force and displacement b) Rate of
work done
c) Rate of displacement d) Product of mass and
acceleration. |
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B) |
Match the items in Column ‘A’ with
their appropriate items in Column ‘B’ and write
correct pairs in your answer books:
| Column ‘A’ |
Column ‘B’ |
| i) Coal gas |
a) Passing steam over white-hot coke |
| ii) Oil gas |
b) Cracking of petrol |
| iii) Water gas |
c) Cracking of kerosene |
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d) Distillation of coal |
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e) Distillation of water |
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C) |
Considering the correlation between the first
pair, complete the second pair and write the second pair in
the answer book: |
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i) |
Alpha particle : Helium nucleus ::
Beta particle : ……… |
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ii) |
Electric fuse wire : Lead :: Filament
of electric bulb : ……… |
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iii) |
Radioactivity : Becquerel :: X-rays
: ……… |
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| Q. 2. |
A) |
Give scientific reasons (any Three): |
6
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i) |
A
wire gets heated when an electric current flows through it. |
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ii) |
The
watch-maker uses convex lens. |
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iii) |
In
cold countries, pipelines carrying water burst. |
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iv) |
Inert gas elements do not take part in chemical
reactions. |
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v) |
Kinetic energy is always positive. |
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B) |
Distinguish between any Two of the following: |
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i)
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Cathode and Anode; |
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ii) |
µ-particles and b-particles; |
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iii)
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Compound microscope and an astronomical telescope. |
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| Q. 3. |
A) |
Solve examples given below (any Three): |
6
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i) |
A
body of mass 500 gm is thrown vertically upwards with a velocity
of 10 m/s. Find its potential energy when it reaches maximum
height. (g = 9.8 m/s2) |
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ii) |
300
calories heat is generated in a wire of resistance 41.8 ohms
when a current of 0.5 ampere flows through it. Find the time
in minutes for which the current was passed. |
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iii) |
The
power of convex lens is 2 diopters. Find its focal length. |
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iv) |
A
30 horse-power vehicle is moving with uniform velocity of
36 km/hr. Find the force exerted by its engine. |
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v) |
Find
the quantity of heat absorbed by a piece of copper of mass
50 gm when its temperature is increased from 20°C to 60°C.
(Sp. Heat capacity of copper = 0.1 cal/g°C) |
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B) |
State two advantages and two difficulties
in the use of solar energy. |
4
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| Q. 4. |
A) |
Draw neat and labelled diagrams (any Three): |
6
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i) |
Electroplating of silver; |
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ii) |
Electric bell; |
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iii) |
Sound cannot travel through vacuum; |
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iv) |
Dispersion of light by a prism. |
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B) |
Show the gradation of properties of the third
row elements considering the following points: |
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i) |
Electronic configuration; |
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ii) |
Size
of atom; |
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iii) |
Metallic and non-metallic character; |
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iv) |
Reducing and oxidising properties |
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OR |
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What
is Myopia and how is it corrected ? Draw appropriate diagrams
for your explanation. |
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| Q. 5. |
A) |
i) Define any Two of the following: |
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1)
Specific heat capacity |
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2)
Nuclear Fission |
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3)
Watt |
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ii) State laws of refraction. |
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B) |
Derive an expression for the equivalent resistance
of three resistances R1, R2 and R3
arranged in parallel. |
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| Q. 6. |
A) |
Solve the following (any Three): |
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i) |
Write two properties of g-rays. |
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ii) |
Classify the following into potential energy and
kinetic energy: |
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a)
Bullet fired from a gun; |
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b)
Stretched bow; |
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c)
Water stored in a dam; |
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d)
Wound spring in a watch. |
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iii) |
Write two disadvantages in direct use of biomass
resources as fuels. |
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iv) |
Write two uses of X-rays. |
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B) |
Two men stand on two cliffs to study propagation
of sound. Explain the following with scientific reasons: |
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i) |
Calculated velocity of sound during day time was
more. |
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ii) |
One
man first observes the flash of gun and then heard the sound
later. |
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iii) |
One
of the men stands between the two cliffs and fires the gun.
If he hears two successive echoes after 2 and 5 seconds respectively,
find out the distance between the two cliffs. (Velocity of
Sound = 340 m/s) |
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