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RAO IIT ACADEMY / NSEJS / Code-JS512 / Solutions
National Standard Examination in Junior Science (NSEJS)
Date: 18 Nov 2018
1.
Di�iculty : Medium
Topics :
Biodiversity,
Archaeabacteria divided by binary fission or fragmentation, or by budding. Some of the archaeabacteria flagella.
They also have ether lipids in cell membranes.
They also have peptidoglycans in their cell wall.
2.
Di�iculty : Medium
Topics :
Biodiversity,
Platyhelminthis or flatworms have a blind sac body plan and thus are not eucoelomates.
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Solutions
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RAO IIT ACADEMY / NSEJS / Code-JS512 / Solutions
3.
Di�iculty : Medium
Topics :
CELL,
Acrosome vesicle is derived from the golgi apparatus during spermiogenisis.
4.
Di�iculty : Medium
Topics :
Health and Disease,
All are features of acquried immunity.
5.
Di�iculty : Medium
Topics :
Biology,
For paddy fields azolla and anabena are used.
6.
Di�iculty : Medium
Topics :
Nervous tissue,
During an anion potential enter the axon while exist the axon, thus the neuron is depolarised.
7. Di�iculty : Medium
Topics :
Genetic Disorders,
Mutant 2 was made to lypase the up, mutant 4 for mutant 2 for the sequence ofaddihired will be (D).
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8.
Di�iculty : Medium
Topics :
MOLECULAR BASIS OF INHERITANCE ,
as gene code is a triplet.
9.
Di�iculty : Di�icult
Topics :
Human Endocrine System,
Stimulation of anterior lobe of pitutary brings about secretion of TSH - thyroid stimulating hormone which brings aboutsecretion of thyroid hormone which helps in development of frog.
10.
Di�iculty : Medium
Topics :
Genetic and Heredity,
The color of coat here is an example of dominant epistatis, where oen gene makes the express of outer gene, here full color (C)(gene C) makes chinchilla , which inturn makes Himalayan and Agouti is recesive to all.
So to get all agothi color, we need a resumed phenotype CC, which will only be possible if both parents here C all etc, which isonly in option (C).
Chinchilla : Himalayan : Agout
11.
Di�iculty : Di�icult
Topics :
Biodiversity,
Bull shark and Alpine salmander.
Bull shark viviparous (odd)
Alpine salmander viviparous (odd)
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12. Di�iculty : Di�icult
Topics :
Health and Disease,
Guanfacine hypercholoride is use in hypertension. It is prescribed with osmotic diuretics
13.
Di�iculty : Medium
Topics :
MOLECULAR BASIS OF INHERITANCE ,
According to Charga�'s rule, amount of purine is equal to amount of pyrimidine.
bonds to T and thus A & T will be present in equal amount and universly C and G will be present equally so
T C A G
Strand I 348 X 650 1400
Strand II 650 1400 348 Y
and
Now in 1 standard number of
solving for
and
14.
Di�iculty : Medium
Topics :
Biotechnology ,
If brinjal was made to compact interaction by balloons (insects).
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15.
Di�iculty : Medium
Topics :
MOLECULAR BASIS OF INHERITANCE ,
Number of generations
So bacteria will have generations.
In generation bacteria growth
16.
Di�iculty : Medium
Topics :
Biodiversity,
(P) - has no membrane found cell organelles, thus is a bacteria.
(Q) - has all membrane organelles and also cell wall and chloroplast, thus is a plant.
(R) - Only genetic material is present so it is a virus.
(S) - No cell wall and no chloroplast, all other organelles are present, thus animal.
(T) - No centriole and no chloroplast is present, thus fungi.
17.
Di�iculty : Medium
Topics :
Genetic Code,
The darkly stained body is that of an extra X chromosome (barr body). For the body to be gain, the parents have to normal andfertile, thus are of and type. The child but su�ers from klinefelter's syndrome.
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18.
Di�iculty : Easy
Topics :
Genetic Code,
Using standard rotation
the product of allele
the product of allele
Now in Ramesh enzyme is present and present in the genotype then is
In Ali and both are formed so genotype
In Sophia, only is present at so
19.
Di�iculty : Easy
Topics :
BIODIVERSITY AND CONSERVATION ,
The highest number of endemic plants are present in and also the habitat lost is so, by defination area is willcovered by regetation.
20. Di�iculty : Easy
Topics :
MOLECULAR BASIS OF INHERITANCE ,
The child of Mary is Jim's. Because both DNA 1 and 5 are present in both Jim and Mary's child, but not in Lou child.
21.
Di�iculty : Easy
Topics :
Thermal expansion,
It's SI unit is
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22.
Di�iculty : Medium
Topics :
Ray Optics,
__________ (i)
__________ (ii)
Total deviation
____________ (iii)
(Using equation (i) and (ii))
Now from
____________ (iv)
From equation (iii) and (iv),
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23.
Di�iculty : Di�icult
Topics :
Sound wave,
Let and be the wavelengths of the two sound waves where
____________ (i)
The lower pitch sound is corresponding to higher wavelength.
So, it's frequency
Or,
We have (as musical interval is )
from ii,
( is speed of sound)
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24.
Di�iculty : Medium
Topics :
Ray Optics,
magnification
and
Given
(negative sign indicates that mirror is concave)
focal length is
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25.
Di�iculty : Di�icult
Topics :
Ray Optics,
It will be of the same size for any position of the point source on the line
26. Di�iculty : Medium
Topics :
Kinematics,
At time , is at a distance from and at a distance from
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27.
Di�iculty : Medium
Topics :
Kinematics,
Speed of the ball at the instant it touches the ground is given by
here and
For the motion inside the cake, let retardation be
then, we have,
using
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28.
Di�iculty : Medium
Topics :
Work ,Energy and power,
Electric energy generated per second = 25 kJ
heat energy consumed per second
heat energy consumed per hour
mass of the fuel consumed per hour
per kg of fuel burnt, electrical energy generated
for 1 ton of fuel burnt, electrical energy generated
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29.
Di�iculty : Medium
Topics :
Optics,
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30.
Di�iculty : Medium
Topics :
Oscillations and Waves,
Time period of one oscillation
For oscillations,
In Pulse
In Pulse
bradycardia
31.
Di�iculty : Medium
Topics :
ELECTRICITY,
For integer
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32.
Di�iculty : Medium
Topics :
Fluids,
Let be the volume of block
In case of floatation
...(1)
Let be the volume of block submerged in salt solution
Fraction of volume remains above the salt solution
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33.
Di�iculty : Easy
Topics :
Units,Dimensions & Error analysis,
34.
Di�iculty : Medium
Topics :
HEAT,
A good absorber is good emitter.
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35. Di�iculty : Di�icult
Topics :
ELECTRICITY,
of ball
...(i)
and ...(ii)
Now, (1)/(2)
from above expression, increases with decrease in .
will be maximum on Mercury.
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36.
Di�iculty : Di�icult
Topics :
SOUND,
at
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37.
Di�iculty : Medium
Topics :
ELECTRICITY,
38.
Di�iculty : Easy
Topics :
ELECTRICITY,
(i) Capacitance of hollow sphere = Capacitance of solid sphere,
for hollow and solid sphere, charge would be same.
(ii) A charged body can attract another uncharged body.
(iii) Electric lines of force never intersect.
39.
Di�iculty : Medium
Topics :
HEAT,
Water has maximum density at so if the water is heated above or cooled below density decreases i.e.,volume increases. In other words, it expands so it overflows in both the cases.
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40.
Di�iculty : Medium
Topics :
MAGNETISM,
In case I & IV
Magnetic moment and magnetic field are antiparallel to each other and this is the condition for maximum potential energy.
41.
Di�iculty : Easy
Topics :
Mole concept,
Ratio of moles of will determine simplest or empirical formula.
42. Di�iculty : Easy
Topics :
Periodic Table,
ratio or nuclear charge w.r.t electrons ratio for is lower than atom.
core electrons or inner shell electrons
experience same shielding force
(Ratio)
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43. Di�iculty : Medium
Topics :
Liquids and gases,
Surface tension is same on earth and space but the height of capillary column is inversely proportional to gravity, hence waterwill rise along its full length.
44.
Di�iculty : Easy
Topics :
Volumetric analysis,
45.
Di�iculty : Medium
Topics :
Volumetric analysis,
46.
Di�iculty : Easy
Topics :
Gaseous State,
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47.
Di�iculty : Medium
Topics :
Gaseous State,
If is constant, Avogadro's law is applicable
48.
Di�iculty : Medium
Topics :
Chemistry,Inorganic,
Topic : Sulphur Compounds,
is sparingly soluble in water and forms a weakly dibasic sulphurous acid.
49.
Di�iculty : Medium
Topics :
STOICHIOMETRY,
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50.
Di�iculty : Easy
Topics :
Ionic equilibrium,
Compounds Approx. Nature insolutionNeutral
BasicAcidicAcidic
Bobby who uses increase value to desirable range at it is salt of (strong base + weak acid)
51.
Di�iculty : Medium
Topics :
Mole concept,
52.
Di�iculty : Medium
Topics :
Chemical Bonding,
X and Z are s-block elements have tendency to form ionic crystals having high melting point.
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53.
Di�iculty : Medium
Topics :
Stoichiometric Calculations,
54.
Di�iculty : Easy
Topics :
Volumetric analysis,
55.
Di�iculty : Medium
Topics :
Redox reactions,
As per law of conservation of mass,
Mass of Iron used + Mass of = Mass of formed + Mass of (Assume )
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56.
Di�iculty : Medium
Topics :
Volumetric analysis,
Solutions (Q) is hydrated acid
(Molar mass = 126 g)
, which is 40 ppm concentration.
57.
Di�iculty : Easy
Topics :
Metallurgy,
Calamine is which is ore of Zinc and not of Aluminium metal.
58.
Di�iculty : Medium
Topics :
Hydrocarbon,
Higher the octane number, higher must be % by weight of iso-octane to give higher e�iciency of engine which means improvedquality of petrol.
59.
Di�iculty : Medium
Topics :
Balancing of redox reactions,
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60.
Di�iculty : Easy
Topics :
Ionic equilibrium,
solution is a basic solution which is going to turn universal indicator or litmus paper Red litmus Blue.
is a salt of
(Weak acid and Strong acid)
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61.
Di�iculty : Medium
Topics :
Circles,
The required circle is as shown with radius
Note that there are two more circles touching and as shown
with radius
with radius
We do not need to calculate because as it is not the largest radius. However, can be calculated as follows (shouldnot be done in the exam). In the following
We have
Solving for we get
Alternately use Stewart's theorem to get directly.
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62.
Di�iculty : Medium
Topics :
Mathematics,
Topic: Number Theory
Product of any four consecutive integers is divisible by and product of two consecutive numbers isdivisible by two. Hence
The above is always divisible by
63.
Di�iculty : Medium
Topics :
Permutations & Combinations,
Key: C or D
If a number appeared 3rd time only in the throw In first throws, 5 numbers appeared twice and one numberappeared once. Let the number appeared once be and the number appeared on throw as
Since and
The only possibility is or
Hence the least number appeared could be or
i.e. either he threw once, twice and thrice or
once, twice and thrice.
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64.
Di�iculty : Medium
Topics :
GEOMETRY,
is equilateral
Drop from to
Area of
65.
Di�iculty : Medium
Topics :
Permutations & Combinations,
Question does not make sence.
Under some assumption we can form three cuboids of the size which isnot in the option.
The question probably meant how many cuboids can be selected from this cube for which we have cuts in each dimensionsfor every cuboid selected there are cuts required in each dimensions giving for which option D is correct.
66.
Di�iculty : Medium
Topics :
Permutations & Combinations,
If has positive divisors, then must be of the form
or where
or
Number of divisors
Here it is assume that is not a multiple of Because if it is, then or or giving number of divisors of
or or as or or Hence is also a possible (but not always an answer)
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67.
Di�iculty : Medium
Topics :
ALGEBRA,
Rationalizing
Now
or
(Here it is assumed that )
Alternately
Applying
or
Applying once again
or
or
* Note that it is assumed for which we get answer as otherwise we will get
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68.
Di�iculty : Medium
Topics :
Permutations & Combinations,
Let and be no. of sides
no. of diagonals and
and
Subtracting we get
divisor of
and
of which only and satisfies
Note : We calculate number of diagonals of a polygon as follows. Let be no. of sides of polygon. Now for a diagonal, everyvertex can be joined with other vertices. This can be done in ways. But in this every diagonal is counted
twice, giving number of diagonals
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69.
Di�iculty : Easy
Topics :
GEOMETRY,
Using ptolemy's theorem in cyclic quadrilateral we get
but
... Note that this is true for any point on minor arc
diameter
Alternately we have equal chords subtend equal angle
as
Now is with
70.
Di�iculty : Easy
Topics :
LINEAR EQUATIONS IN TWO VARIABLES,
and
and
sum of digits
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71.
Di�iculty : Easy
Topics :
Sequence & Series,
Now
72.
Di�iculty : Medium
Topics :
Sequence & Series,GEOMETRY,
in A.P.
Sum of digits of
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73.
Di�iculty : Easy
Topics :
Quadratic Equations,
As
74.
Di�iculty : Medium
Topics :
Mathematics,
Topic : Number Theory
but
Total distinct integers.
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75.
Di�iculty : Medium
Topics :
GEOMETRY,
Take
Now
Note: Here it is assumed that m and n are co prime integers without which any answer is correct. For e.g. consider m=26/11and n=117/11 for which m/n=2/9 and m+n=13.
76.
Di�iculty : Easy
Topics :
Sequence & Series,
...(1)
...(2)
Product of terms =
* It is assumed that
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77.
Di�iculty : Medium
Topics :
Mathematics,
Topic : Number Theory
As is divisible by
is divisible by can't be divisible by
or
Now if is divisible by as well
can be anything from possibilities
If then must be divisible by as isn't divisible by
No. of pairs
No option matching
78.
Di�iculty : Medium
Topics :
GEOMETRY,
Draw parallel from to meeting in
Now let
Alternately, apply Menelau's theorem in with as transversal
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79.
Di�iculty : Medium
Topics :
Mathematics,
Topic : Number Theory
and
80.
Di�iculty : Medium
Topics :
GEOMETRY,
As and have same height and sum of parallel sides, they have same area say
Let
Now
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