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PHYSICS
-I
SCIENCE Paper
(Two hours)
Answers to this Paper must be written on the poper provided separately.
You
will not
be allowed to
This time is to be
The time given at the head
section
I
of
write during
synt in reading
The inrended marks
for
first lS minutes.
the Question PaWr.
this Paper is the time
is compulsory. Anempt any
the
allowedfor writing the answers.
four questionsfrom section'Ir.
quesrions or parts of questions are given in brackets
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SECTION I (40 Marks)
Attempt all qaestions from this Section
Question
(a) (i)
(ii)
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Give an example of anon contactforcewhich is always of attractive naiure.r
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How does the magnitude of this non contactforceon the two bodies depend
on the distance of separation between them?
(b)
A boy weighing 40kgf climbs upa stair of 30 steps each Z}cmhigh in 4 minute
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and a girl weighing 30kgf does *rc same in 3 minutes. Compare:-
(i)
The work done by them.
(ii) The power developed
(c)
by them.
With reference to the terms Mechanical Advantage, Velocity Ratio and
efficiency of a machine, name and define the term that will not change for a
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machine of a given design.
(d)
Calculate the mass of ice requird to lower the temperature of 3009 of water at
40oC to water at 0oC.
(specific latent heat of ice:336 Jlg,Specific heat capacity of water4 .z Jlgtc)
This Paper consists of 7 printed pages and
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@ Copyright reserved.
1
blank page.
Turn over
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(e)
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statements:
What do you understand by the following
(i) The heat capacity of the body is 60 JK-t'
(ii) The specific heat capacity of lead is 130 Jkg-t6-t'
Question 2
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(a)Staterwofactorsuponwhichtheheatabsorbedbyabodydepends.
(b)Aboyusesbluecolouroflighttofirrdtherefractiveindexofglass.Hethen
light' will the refractive index be the
repeats the experiment using red colotrof
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Give a rieason to stlpport your answer'
same or different in the two cases?
(c)
the pdhof light ray till it emerges
copy the diagram given below and complae
gtass is 42"' tn your diagram mark the
out of the prism. The critical angle of
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angles wherever necessary'
(d)
State the dependence of angle of
deviation:
(i)
On the refractive index of the
(ii)
On the wavelength of light'
*
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m*erial of the pri$n'
(e)Theratioofamplitudeofwowavesis3:4.whdisdleraiooftheir:
(i)
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loudness?
(ii) frequencies?
Question 3
(a)
State rwo ways by which the
string can be increased'
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of
@uency of transwrse vibrations
a stretched
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(b)
What is meant by noise pollution? Name one source of sound causing noise
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pollution.
(c)
The
V-l graph for a series combination and for a parallel combination of two
resistors is shown in the figure below. Which of the two
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A or B, represents the
parallel combination? Give a reason for your answer.
(d) A music s)'stem draws a current of 400 mA w'hen connected to a 12 V hattery.
(i)
\\'hat is the resistance of the music system?
(iit
The music system is left playing for several hours and finallv the battery
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voltage drops and the music system stops playing when the current drops
to 320 mA. At what batterl,voltage does the music system stop playing?
(e) Calculate
the quantity of heat produced in a20 O resistor carrying 2.5A current
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in 5 minutes.
Question 4
(a)
State the characteristics required of a good thermion emitter.
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(b) An element zSA decays to ssR::2 after emitting2 a particles and I B parricle.
Find the atomic number and atomic mass of the element
(c)
.{ radioactive
substance is oxidized.
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S.
Will there be anr change in the nature of
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its radioactil,itl,? Give a reason for your answer.
(d)
State the characteristics required in a material
to be used as an effective
tuse
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wire.
(e)
Which coil of a step up transfbrmer is made thicker and wh5,?
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3
t2)
Turn 0ver
SECTION
II
(40 Marks)
Attempt any four questions from this Section
Question 5
(a) A stone of mass 'm' is rotated in a circular path with a uniform speed by tying a
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questions:
strong string with the help of your hand. Answer the following
(i)lsthestonemovingwithauniformorvariablespeed?
(ii)
ls the stone moving with a uniform acceleration? tn *'hich direction does
the acceleration act?
what kind of force acts on the hand and state is direction?
(iii)
(b)
From the diagram given below, answef the questions that follow:
(i)
What kind of PulleYs are A and B?
(ii)
State the PurPose of PulleY B.
(iii) what effort
has to be applied at
c
to just raise the load
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L:}akgfl
(Neglect the weight of pulley A and friction)'
(c) (i)
An effort is applied on the bigger wheel of a gear having 32 teeth' It is used
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to turn a wheel of 8 teeth. Where is it used?
(ii)
A pulley system has three pulleys. A load of I20N is overcome by applying
an effort of 50N. Calculate the Mechanical Advantage and Efficiency of
this sYstem.
Question 6
(a) (i) What is the principle of method of mixtures?
(ii) What is the other name given to it?
(iii)
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Name the law on which the principle is based'
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(b)Someiceisheatedataconstantrate,anditstemperatureisrecordedaftereveryt3]
Draw a temperature time graph to
few seconds, till steam is formed at 100oC.
phase changes in your graph'
represent the change. Label the two
(c)Acoppervesselofmassl00gcontainsl50gofwaterat50oC.Howmuchicet4]
is needed to cool it to 5oC?
Given :
Specific heat capacity of
copper :
0'4
J g-t
Specific heat capacity of
water =
4'2
!
Specific latent heat of fusion of ice
=
f'r
og-t
og't
336 J g-'
Question 7
(a)(i)Writearelationshipber*.eenangleofincidenceandangleofrefractionfor
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a given Pair of media'
to another having different
when a ray of light enters from one medium
(ii)
phenomenon occur?
optical densities it bends' Why does this
(iii)Writeoneconditionwhereitdoesnotbendwhenenteringamediumof
different oPtical densitY'
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(b)Alensproducesavirtualimagebetweentheobjectandthelens.
(i)
Name the lens'
(ii) Draw a ray diagram
to show the formation of this image'
(c)Whatdoyouunderstandbytheterm.Scatteringoflight'?Whichcolourof
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white light is scattered the least and why?
Question 8
(a) (i)
(ii)
Name the waves used for echo depth sounding'
purpose'
Give one reason for their use for the above
(iii)
(b) (i)
(ii)
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to us?
Why are the waves mentioned by you not audible
What is an echo?
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place'
State two conditions for an echo to take
Turn Over
(c) (i)
(ii)
Name the phenomenon involved in tuning a radio set to a particular station.
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Define the phenomenon named by you in part (i) above.
(iiD What do you understand by loudness of sound?
(iv) In which units is the loudness of
sound measured?
Question 9
(a) (i)
Which particles are responsible fbr cun€nt in conductors?
(ii)
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To,which wire of a cable in a power circuit should the metal case of a
geyser be corinected?
(iii) To which wire shouldthe fuse be connected?
(b) (i)
Name the transformer used in the power transmiuing station of a power
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plant.
(ii)
What type of current is transmitted from the power station?
(iiD At what voltage is this
(c)
current available to our household?
A battery of emf lZY andintemal resisiance 2 O is connectgd with two resistors
A and B of resistance 4 Q and 6 O respectively joined in series.
40
6f)
Find:
(i)
Current in the circuit.
(ii)
The terminal voltage ofthe cell.
(iii)
The potential difference auoss 6Q Resistor.
(iv)
Electrical energy spent per minute in 4O Resistor.
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Question
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(a) Arrange c, B and T rays in ascending order
(i)
with respect to their
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Penetrating Power'
(iii) Biological effect'
(b) (i)
- the ftrnction of anode?'
In a cathode ray tube what is -- -
(ii)
tube'
taking place in a cathode ray
State the energy conversion
(iii)
tube'
Write one use of cathode ray
(c) (i)
when a p
nucleus of a radioactive element
Represent the change ln"the
(i,)Whatisthenamegiventoelementswithsarnemassnumberand
difTerent atomic number?
(iii)Underwhichconditionsdoesthenueleusofanatomtendtobe
radioactive?
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