datavorous/entrance-exam-dataset huggingface dataset:
The y co-ordinate of the centre of mass of the system of three rods of length 2a and two rods of length a as shown in the figure is (Assume all rods to be of uniform density)

Options:
A 9a83
B 9a163
C zero
D 8a3

The correct answer is:
9a163

Solution:
Since all the rods are of same, uniform density we can treat them as point masses placed at their centres

hence the y co-ordinate of centre of mass is
yCM=m1y1+m2y2+m3y3+m4y4+m5y5m1+m2+m3+m4+m5
=2m32a+2m0+2m0+m34a+m34a8m=9a163

Topic: Physics, Center of Mass Momentum and Collision, NEET
The 'Y' in the following sequence of reactions
is

Options:
A propene
B propan-1-ol
C propan-2-ol
D propyne

The correct answer is:
propan-1-ol

Solution:

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
The Young's double-slit experiment is performed with blue and with the green light of wavelengths 4360 Aâ and 5460 Aâ respectively. If x is the distance of 4th maximum form the central maximum, then

Options:
A

x (blue) = x (green)

B x (blue) > x (green)
C x (blue) < x (green)
D x bluexgreen=54604360

The correct answer is:
x (blue) < x (green)

Solution:
Distance of nth maxima, x=nλDd∝λ
As λb<λg
∴ xblue<xgreen

Topic: Physics, Wave Optics, NEET
The Young's modulus of a wire of length L and radius r is Y. If the length and radius are reduced to L2 and r2, then its Young's modulus will be

Options:
A Y2
B Y
C 2Y
D 4Y

The correct answer is:
Y

Solution:
Young's modulus of wire does not vary with the dimensions of the wire. It is a property of the material.

Topic: Physics, Mechanical Properties of Solids, NEET
The Young's modulus of steel is twice that of brass. Two wires of same length and of same area of cross-section, one of steel and another of brass are suspended from the same roof. If we want the lower ends of the wires to be at the same level, then the weights added to the steel and brass wires must be in the ratio of:

Options:
A 2 : 1
B 4 : 1
C 1 : 1
D 1 : 2

The correct answer is:
2 : 1

Solution:
Y=WA×lΔl
So, Δl= WlAY
Δe1=Δe2

w1lAY1= w2lAY2
⇒w1w2= Y1Y2=2

Topic: Physics, Mechanical Properties of Solids, NEET, NEET 2015 (Phase 2)
The Young's modulus of the material of wire is 2Ã1010 N m-2. If the elongation strain is 1%, then the energy stored in the wire per unit volume in J m -3 is

Options:
A 106 J m-3
B 108 J m-3
C 2Ã106 J m-3
D 2Ã108 J m-3

The correct answer is:
106 J m-3

Solution:
Per unit volume energy stored
=12ÃYÃstrain2=12ÃYÃlL2
given l=LÃ1%
or l=L100
Thus per unit volume energy stored =12Ã2Ã1010ÃL100L2
=106 J m-3

Topic: Physics, Mechanical Properties of Solids, NEET
The zone at the edge of a. lake or ocean which is alternatively exposed to air and immersed in water is called

Options:
A Pelagic zone
B Benthic zone
C Lentic one
D Littoral zone

The correct answer is:
Littoral zone

Solution:
The zone at the edge of a lake or ocean which is alternatively exposed to air and immersed in water is called a littoral zone.

Topic: Biology, Ecosystem, NEET
The zone of atmosphere in which the ozone layer is:

Options:
A Ionosphere
B Mesosphere
C Stratosphere
D Troposphere

The correct answer is:
Stratosphere

Solution:
Ozone is present in two regions of the atmosphere-troposphere and stratosphere. About 10% of atmospheric ozone is in the troposphere, and the large amount of ozone is present in the stratosphere region which is often referred to as the “good ozone layer.”

Topic: Biology, Environmental Issues, NEET, NEET 2014
The zygosity of an organism for a particular phenotype can be identified by crossing it with

Options:
A AaBb
B aabb
C aaBb
D Aabb

The correct answer is:
aabb

Solution:
A test cross is a process to examine and identify whether the organism is heterozygous or not. In it, the organisms are crossed with the recessive homozygous as it will ensure the expression of the dominant character in heterozygous form for F1 generation enabling us to know the zygosity.

Topic: Biology, Principles of Inheritance and Variation, NEET
Then salt ‘P’ in above reaction is

Options:
A Na2C r O4
B ZnSO4
C CuSO4
D AgNO3

The correct answer is:
CuSO4

Solution:
Here salt 'P' is CuSO4 and reactions are as follows

Topic: Chemistry, d and f Block Elements, NEET
Theory of inheritance of acquired characters was put forth by

Options:
A Lamarck
B Weismann
C Galton
D de Vries

The correct answer is:
Lamarck

Solution:
Jean Baptiste Lamarck (1744–1829), a French biologist putforth his views on the evolution of life as a theory of 'inheritance of acquired characters' in his book 'Philosophic Zoologique' (1809).

Topic: Biology, Evolution, NEET
Theory of origin of species by Darwin and Wallace doesn't explain all of these except

Options:
A arrival of the fittest.
B the development of vestigial organs
C over-specialization of some organs like tusk of elephants
D the cause of struggle for existence.

The correct answer is:
the cause of struggle for existence.

Solution:
Darwin's theory on origin of species states that over reproduction and lack of available resources causes struggle for existence. In the struggle for existence, nature will select those organisms with favourable variations (survival of the fittest). Continuous environmental changes along with natural selection leads to origin of species.

Topic: Biology, Evolution, NEET
There are 5 test tubes having a culture medium containing rough colonies of Streptococcus pneumoniae. The following substances were added in them. Which of these test tubes will show smooth colonies of Streptococcus pneumoniae on incubation for some time?

Test tube I: RNA from a heat-killed smooth strain of Streptococcus pneumoniae

Test tube II: DNA from a heat-killed smooth strain of Streptococcus pneumoniae

Test tube III: Protein from a heat-killed smooth strain of Streptococcus pneumoniae

Test tube IV: Carbohydrate from a heat-killed smooth strain of Streptococcus pneumoniae

Test tube V: Heat killed smooth strain of Streptococcus pneumoniae incubated with DNAse enzyme

Options:
A II and V
B II, III and IV
C I and II
D II

The correct answer is:
II

Solution:
This example is the basis of Avery, Mcleod and McCarty's experiment. They proved that DNA is the genetic material. That means only DNA from heat-killed smooth strain could enter rough strain and transform them into smooth colonies. In Test tube V, DNAse enzyme will destroy DNA in the smooth strain, and hence, it will not be able to transfer its DNA.

Topic: Biology, Molecular Basis of Inheritance, NEET
There are 10 flowers in one individual plant of Crotalaria. In each microsporangium of every stamen of all the flowers, there are 30 microspore mother cells. How many pollen grains are formed from that plant?

Options:
A 4,000
B 10,000
C 24,000
D 48,000

The correct answer is:
48,000

Solution:
The answer is 48000 because every flower of crotolaria would have 10 stamens, 10 stamens would have 10 anthers, 10 anthers would have 40 microsporangia, each microsporangia has 30 30 microspore mother cells so, 40 microsporangia would have 1200 microspore mother cells. Each microspore would produce 4 pollen grains, taking the number of pollen grains produced by a flower to 1200 X 4 = 4800. Since there are 10 flowers the answer would be 4800 X 10 = 48000 pollen grains.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
There are 11 pairs of ribs in a man

Options:
A True
B False
C Maybe false
D Cannot be defined

The correct answer is:
False

Solution:
There are 12 pairs of ribs in a man.

Topic: Biology, Locomotion and Movement, NEET
There are 20 different types of amino acids that help in the formation of proteins. They differ from each other in the structure because of their

Options:
A Carboxyl group
B Amine group
C Functional group as R
D Hydrogen's orientation

The correct answer is:
Functional group as R

Solution:
All amino acids which form proteins are alpha amino acids with COOH (carboxyl group), NH2 (amine group), H and a variable R group attached to a central carbon atom. They differ from each other in the orientation of R group, e.g., R group is 'H' in glycine, 'CH3 ' in alanine and 'CH2OH' in serine.

Topic: Chemistry, Biomolecules, NEET
There are certain sequences of DNA that are termed as mobile or jumping genes and are useful as vectors. Such sequences are called as

Options:
A YAC
B Plasmid
C Transposons
D Phasmid

The correct answer is:
Transposons

Solution:
Transposons are DNA sequences that have the ability to move within the genome. Such changes in the position can make or remove mutations even altering the genetic identity of the genome. This ability can be harnessed as a vector to insert genes of our choice into the host genome.

Topic: Biology, Biotechnology - Principles and Processes, NEET
There are Fibres of the tract that are covered with a myelin sheath. These fibres are known as

Options:
A Grey matter
B White matter
C Spinal Cord
D None of the above

The correct answer is:
White matter

Solution:
White matter – Fibres of the tract are covered with a myelin sheath.

Topic: Biology, Neural Control and Coordination, NEET
There are five alleles of a particular gene in a population. The total number of different genotypes (for this allele) in the population will be

Options:
A 5
B 15
C 25
D 30

The correct answer is:
15

Solution:
Consider the four alleles in the population to be A1, A2, A3, A4 and A5. An individual can have only two alleles at a time. So the various genotypes will be A1A1, A1A2, A1A3, A1A4, A1A5, A2A2, A2A3, A2A4, A2A5, A3A3, A3A4, A3A5, A4A4, A4A5, A5A5 (total 15). The general formula for types of genotypes is nn+1/2, where n is the number of alleles in the population.

Topic: Biology, Principles of Inheritance and Variation, NEET
There are four forces acting at a point P produced by strings as shown in Fig, which is at rest. Find the forces F1and F2.

Options:
A F1= $\frac{1}{\sqrt{2}}$, F2=$\frac{1}{\sqrt{2}}$
B F1= $\frac{\sqrt{3}}{2}$, F2=$\frac{\sqrt{3}}{2}$
C F1=$\frac{\sqrt{3}}{2}$ , F2=$\frac{1}{\sqrt{2}}$
D F1= $\frac{1}{\sqrt{2}}$, F2=$\frac{\sqrt{3}}{2}$

The correct answer is:
F1= $\frac{1}{\sqrt{2}}$, F2=$\frac{\sqrt{3}}{2}$

Solution:
Correct Option is : (D)
F1= $\frac{1}{\sqrt{2}}$, F2=$\frac{\sqrt{3}}{2}$

Topic: Chemistry, Laws of Motion, NEET
There are more than ________ species of ants, 3,00,000 species of _______, 28,000 species of ________ and nearly ________ species of orchids.

Options:
A 20,000; insects; fishes; 30,000
B 30,000; beetles; birds; 20,000
C 20,000; beetles; fishes; 20,000
D 40,000; fishes; beetles; 10,000

The correct answer is:
20,000; beetles; fishes; 20,000

Solution:
The enormous diversity of life that we would encounter with the rich variety of living organisms are enormous and there are more than 20,000 species of ants, 3,00,000 species of beetles, 28,000 species of fishes, and nearly 20,000 species of orchids.

Topic: Biology, Biodiversity and its Conservation, NEET
There are _______ pairs of ribs. Ribs is a ______ bone connected dorsally to the _________ and ventrally to the ________ .

Options:
A 22 pairs, thin flat bone, vertebral column and clavicle.
B 12 pairs, thin flat bone, clavicle and diaphragm.
C 22 pairs, thin circular bone, sternum and vertebral column.
D 12 pairs, thin flat bone, vertebral column and sternum.

The correct answer is:
12 pairs, thin flat bone, vertebral column and sternum.

Solution:
There are 12 pairs of ribs. Each rib is a thin flat bone connected dorsally to the vertebral column and ventrally to the sternum. It has two articulation surfaces and is hence called bicephalic. The first seven pairs of ribs are called true ribs. Dorsally, they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage. The 8th, 9th and 10th pairs of ribs do not articulate directly with the sternum but join the seventh rib with the help of hyaline cartilage. These are called vertebrochondral (false) ribs. The last 2 pairs (11th and 12th) of ribs are not connected ventrally and are, therefore, called floating ribs. Thoracic vertebrae, ribs and sternum together form the rib cage

Topic: Biology, Locomotion and Movement, NEET
There are the alleles that are able to express themselves independently when found together in a heterozygote are called ___.

Options:
A Codominance
B Incomplete dominance
C Point mutation
D None of the above

The correct answer is:
Codominance

Solution:
There are the alleles that are able to express themselves independently when found together in a heterozygote are called codominance.

Topic: Biology, Principles of Inheritance and Variation, NEET
There are three canonical structures of naphthalene. Examine them and find the correct statement among the following:

Options:
A All C-C bonds are of some length
B C1-C2 bond is shorter than C2-C3 bond.
C C1-C2 bond is longer than C2-C3 bond.
D None

The correct answer is:
C1-C2 bond is shorter than C2-C3 bond.

Solution:
C 1 - C 2 Bond has more double bond character whereas
C 2 - C 3 Bond has more single bond character

Topic: Chemistry, General Organic Chemistry, NEET
There are three endocrine glands involved in carbohydrate metabolism, mark the correct set.

Options:
A Pancreas, neurohypophysis and adrenal
B Pancreas, adenohypophysis and thyroid
C Pancreas, pituitary and liver
D Pancreas, adenohypophysis and thymus

The correct answer is:
Pancreas, adenohypophysis and thyroid

Solution:
The pancreas secretes insulin which is hypoglycemic affecting glycogenesis; pituitary controls the carbohydrate metabolism indirectly through ACTH and thyroid stimulates the absorption of monosaccharides from the intestine and stimulates glycogenolysis.

Topic: Biology, Digestion and Absorption, NEET
There are three genes $\mathrm{a}, \mathrm{b}$ and $\mathrm{c}$. The percentage of crossing over between $a$ and $b$ is $20 \%, b$ and $c$ is $28 \%$ and $a$ and $c$ is $8 \%$. What is the sequence of genes on chromosome?

Options:
A $b, a, c$
B $a, b, c$
C $a, c, b$
D None

The correct answer is:
$b, a, c$

Solution:
The sequence of $a, b, c$ gene is $b, a, c$

Topic: Biology, Principles of Inheritance and Variation, NEET, NEET 2002
There are two charged metallic spheres S 1 and S 2 of radii R 1 and R 2 respectively. The electric fields E 1 and E 2 on their surfaces are such that E 1 / E 2 = R 1 / R 2 . Then the ratio V1/V2 of their electrostatic potentials on each sphere is

Options:
A R1R23
B R1R2
C R2R1
D R1R22

The correct answer is:
R1R22

Solution:
E1E2=R1R2V1V2=E1R1E2R2=R1R2×R1R2=R1R22

Topic: Physics, Electrostatics, NEET
There are two different percentage solutions of phenol which are 0.2% and 1%. They will act as _____ and _____ respectively.

Options:
A antiseptic, disinfectant
B disinfectant, antiseptic
C analgesic
D antipyretic

The correct answer is:
antiseptic, disinfectant

Solution:
Antiseptics are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces.

Disinfectants are applied to inanimate objects such as floors, drainage system, instruments, etc.

Same substances can act as an antiseptic as well as disinfectant by varying the concentration. For example, 0.2 percent solution of phenol is an antiseptic while its one percent solution is disinfectant.

Topic: Chemistry, Chemistry in Everyday Life, NEET
There are two forces each having same magnitude 10 N. One is inclined at an angle of 30 o and other is inclined at an angle of 135 o to the positive direction of x -axis. The x and y components of the resultant are

Options:
A 1.59 Ni^ and 12.07 Nj^
B 10âNi^ and 10âNj^
C 1.59 Ni^ and 10 Nj^
D 1.59âNi^ and 2 Nj^

The correct answer is:
1.59 Ni^ and 12.07 Nj^

Solution:
After resolving forces in xy- direction, we get
Along x direction, net force;
F x =10 cos 30 o + âcos 45 o =10 3 2 â 1 2 =1.59 N
Along y direction, net force;
Fy=10sin30o+10â sin45o
F y =10( 1 2 + 1 2 )
=12.07âN
Thus forces in x and y direction are 1.59âN and 12.07âN respectively.

Topic: Physics, Mathematics in Physics, NEET
There are two identical balls of the same mass, one being solid and the other being hollow. How will you distinguish them without weighing?

Options:
A By spinning them using equal torques
B By determining their moment of inertia
C By rolling them down an inclined plane
D By any one of these methods

The correct answer is:
By any one of these methods

Solution:
Solid and hollow balls can be distinguished by any of the three methods.
Here we have, Ih>Is.
When torques are equal, angular acceleration α of hollow must be smaller than α of solid. Similarly, on rolling, solid ball will reach the bottom before the hollow ball

Topic: Physics, Rotational Motion, NEET
There are two identical small holes of an area of cross-section a on the opposite sides of a tank containing a liquid of density ρ . The difference in height between the holes is h. Tank is resting on a smooth horizontal surface. The horizontal force which will have to be applied on the tank to keep it in equilibrium is

Options:
A ghρa
B 2ghρa
C 2Ïagh
D ρgha

The correct answer is:
2ρagh

Solution:
Thrust force
F = F 1 - F 2 = Ï av 1 2 - Ï av 2 2
=aÏ2gh1-aÏ2gh2
=2Ïagh1-h2
=2Ïagh

Topic: Physics, Mechanical Properties of Fluids, NEET
There are two identical small holes of area of cross-section A on the opposite sides of a tank containing a liquid of density ρ. The difference in height between the holes is h. Tank is resting on a smooth horizontal surface, horizontal force which has to be applied on the tank to keep it in equilibrium is

Options:
A ρghA
B 2gh/ρA
C 2ÏghA
D ρgh/A

The correct answer is:
2ρghA

Solution:
Rate of change of momentum=dpdt
F=FQ-FP=dpQdt-dpPdt=dmdtQÃVQ-dmdtPÃVP
=AÏvQÃvQ-AÏvPÃvP
=AÏvQ2-vP2 ...(i)

PP+12ÏvP2+Ïgh=PQ+12ÏvQ2+0 âµPP=PQ
â12ÏvQ2-vP2=Ïgh
â´F=2AÏgh (from (i))

Topic: Physics, Mechanical Properties of Fluids, NEET
There are two identical small holes on the opposite side of a tank containing a liquid. The tank is open at the top. The difference in height of the two holes is h as shown in the figure. As the liquid comes out of the two holes, the tank will experience a net horizontal force proportional to :

Options:
A h1/2
B h
C h3/2
D h2

The correct answer is:
h

Solution:
F = v dm dt
= v Ï A dx dt
F = Ï A v 2
F net = F 1 - F 2
= Ï A v 1 2 - v 2 2
and from equation as speed of efflux
v 1 2 = v 2 2 + 2 gh
â v 1 2 - v 2 2 = 2 gh
F net = 2 Ï Agh Î± h

Topic: Physics, Mechanical Properties of Fluids, NEET
There are two identical springs each of spring constant k. Here springs, pulley and rods are massless and the block has mass m. What is the extension of each spring at equilibrium?

Options:
A 2mgk
B mg2k
C 3mg4k
D mgk

The correct answer is:
mgk

Solution:
Draw a free body diagram of above figure
FBD of lower rod
kx+kx=2 mg
â x=mgk

Topic: Physics, Oscillations, NEET
There are two opposing views about origin of modern man. According to one view Homo erectus in Asia were the ancestors of modern man. A study of variation in DNA, however suggested African origin of modern man. What kind of observation on DNA variation could suggest this?

Options:
A Greater variation in Asia than in Africa
B Greater variation in Africa than in Asia
C Similar variation in Africa and Asia
D Variation only in Asia and no variation in Africa

The correct answer is:
Greater variation in Africa than in Asia

Solution:
There is evidence that almost all of the Hominid evolution occurred in Africa and Asia and that the evolution of the human species took place in Africa. Several species belonging to the genus Homo can be recognized from the fossil record. For example, Homo habilis lived in Africa, about two million years ago and was characterized by having a larger brain than Australopithecus, used tools, and was bipedal. Another species, Homo erectus appeared about 1.7 million years ago, used fire, and is believed to have migrated to Asia and Europe. Fossils of the so-called 'Java man' and 'Peking man', belong to Homo erectus. Homo erectus was replaced by Homo sapiens. Homo erectus appears to have survived for another 250,000 years when it was finally replaced by Homo sapiens migrating from Africa.

Topic: Biology, Evolution, NEET
There are two plane mirrors placed at some angle θ with each other. A ray incident on the first mirror travels parallel to the second mirror after reflection and it travels parallel to the first mirror after two successive reflections. Find angle θ between the mirrors.

Options:
A 90°
B 60Â°
C 120°
D 30°

The correct answer is:
60°

Solution:
Î´=90+Î±-Î¸
90+Î±-Î¸=Î¸ and 90-Î±=Î¸
180-Î¸=2Î¸
Î¸=60Â°

Topic: Physics, Ray Optics, NEET
There are two plants A and B with respective critical photoperiod of 13 hours and 11 hours. When they are exposed to light for a period of 12 hours, it initiated flowering in both. Which of the following conclusions is most appropriate for these plants?

Options:
A Both plant A and B are long day plants
B Both plant A and B are short day plants
C Plant A is short day plant and plant B is long day plant
D Plant A is long day plant and plant B is short day plant

The correct answer is:
Plant A is short day plant and plant B is long day plant

Solution:
Plant A is a short-day plant (A plant that flowers only after being exposed to light periods shorter than a certain critical length.) and plant B is a long-day plant (A plant that flowers only after being exposed to light periods longer than a certain critical length).

Topic: Biology, Plant - Growth and Development, NEET
There are two radioactive substances A and B. Decay constant of B is two times that of A. Initially, both have an equal number of nuclei. After n half-lives of A, the rate of disintegration of both is equal. The value of n is

Options:
A 4
B 2
C 1
D 5

The correct answer is:
1

Solution:
Let Î»A=Î»â´Î»B=2Î»
If N0 is total number of atoms in A and B at t=0, then initial rate of disintegration of A=Î»N0, and initial rate of disintegration of B=2Î» N0
As Î»B=2Î»A
â´TB=12TA
ie, half-life of B is half the half-life of A.
After one half-life of A
-dNdtA=Î»N02
Equivalently, after two half lives of B
-dNdtB=2Î»N04=Î»N02
Clearly, -dNdtA=-dNdtB
after n=1 i.e., one half-life of A

Topic: Physics, Nuclear Physics, NEET
There are two radioactive substances A and B . Decay constant of B is two times that of A . Initially both have equal number of nuclei. After n half lives of A rate of disintegration of both are equal. The value of n is

Options:
A 1
B 2
C 4
D all of these

The correct answer is:
1

Solution:
Let λA=λ and λB=2λ
Initially rate of disintegration of A is λN0 and that of B is 2λN0 .
After one half-life of A , rate of disintegration of A will becomes λN02
and that of B would also be λN02 (half-life) of B=12 (half-life of A )
So, after one half-life of A or two half-lives of B .
-dNdtA
=-dNdtB
∴n=1

Topic: Physics, Nuclear Physics, NEET
There are two thin spheres A and B of the same material and same thickness. They behave like black bodies. The radius of A is double that of B and both have the same temperature T. When A and B are kept in a room of temperature T0 <T, the ratio of their rates of cooling is (assume negligible heat exchange between A and B)

Options:
A 2:1
B 1:1
C 4:1
D 8:1

The correct answer is:
1:1

Solution:
The rate of heat loss by a thin hollow sphere of thickness ∆x, mean radius r and made of density ρ is given by
mSdTdt=-eσ A T4-T04
ρ 4πr2 ∆x SdTdt=-eσ 4πr2 T4-T04
dTdt=-eσ T4-T04S ∆x is independent of radius
Hence the rate of cooling is same for both spheres.

Topic: Physics, Thermal Properties of Matter, NEET