datavorous/entrance-exam-dataset huggingface dataset:
When the voltage applied to an X-ray tube increased from V1=15.5 kV to V2=31 kV, the wavelength interval between the KÎ± line and the cut-off wavelength of the continuous X-ray spectrum increases by a factor of 1.3. Identify the element.

(Take: hc=1240 eV nm and R=1Ã107 N m-1)

Options:
A Iron
B Manganese
C Nickel
D Tin

The correct answer is:
Iron

Solution:
λth=hceVa
1λKα=Rz-12112-122
1310λKα-λth=λKα-λth2
310λKα=1310-12λth
3104×10-73Z-12=81012.4×10-715.5×103
⇒50008=Z-12
625=Z-12 ⇒Z=26

Topic: Physics, Dual Nature of Matter, NEET
When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be:

Options:
A 60 watt
B 180 watt
C 10 watt
D 20 watt

The correct answer is:
20 watt

Solution:
The resistance of each bulb is $\frac{V^2}{P}$ $=\frac{(200)^2}{60} \Omega$ when three bulbs are connected in series then equivalent resistance is $\frac{3 \bullet(200)^2}{60}$
$\therefore \quad$ Power $P=\frac{V^2}{R_{e q}}=20 \mathrm{~W}$

Topic: Physics, Current Electricity, NEET, NEET 2004
When to a copper sulphate solution, excess of ammonium hydroxide added then

Options:
A No change is observed
B Blue precipitate of copper hydroxide is obtained
C A deep blue solution is obtained
D Black precipitate of copper oxide is obtained

The correct answer is:
A deep blue solution is obtained

Solution:

Topic: Chemistry, d and f Block Elements, NEET
When transfer of pollen grains occurs over the surface of water, it is called

Options:
A Entomophily
B Epihydrophily
C Hypohydrophily
D Myrmecophily

The correct answer is:
Epihydrophily

Solution:
Entomophily is pollination by insects. Myrmecophily is pollination by ants. The pollination which takes place on the surface of water is called epihydrophily. The pollination which takes place inside the water is called hypohydrophily. In Vallisneria, the female flower reach the surface of water by the long stalk and the male flowers or pollen grains are released on to the surface of water. Thus it shows epihydrophily

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
When two atoms of hydrogen combine to form a molecule of hydrogen gas, the energy of the molecule is

Options:
A higher than that of the separate atoms
B equal to that of the separate atoms
C lower than that of the separate atoms
D sometimes lower and sometimes higher

The correct answer is:
lower than that of the separate atoms

Solution:
When two atoms of hydrogen combine to form a molecule of hydrogen gas, the energy of the molecule is lower than that of the separate atoms as a molecule is always more stable than the separate atoms, the energy of molecule is always less than that of separate atoms.

Topic: Chemistry, s Block Elements, NEET
When two different materials A and B having atomic number Z1 and Z2 are used as the target in Coolidge γ-ray tube at different operating voltage V1 and V2 respectively their spectrums are found as below.

The correct relation is

Options:
A V1>V2 and Z1>Z2
B V1<V2 and Z1<Z2
C V1<V2 and Z1>Z2
D V1>V2 and Z1<Z2

The correct answer is:
V1>V2 and Z1<Z2

Solution:
λ min=hceV
⇒ λ∝1V
âµ λ2> λ1 (see graph)
⇒ V1>V2
f=aZ-b Moseley's law
f ∝Z-12
⇒ λ ∝1Z-12 (âµf∝1λ)
λ1> λ2 (see graph for characteristic lines)
⇒ Z2> Z1

Topic: Physics, Electromagnetic Waves, NEET
When two displacements represented by y1=a sin⁡(ωt) and y2=bcos⁡ωt are superimposed the motion is:

Options:
A not a simple harmonic.
B simple harmonic with amplitude ab.
C simple harmonic with amplitude a2+b2.
D simple harmonic with amplitude a+b2.

The correct answer is:
simple harmonic with amplitude a2+b2.

Solution:
y1=asin⁡ωt
y2=bcos⁡ωt=bsin⁡ωt+π2
Amplitude A=a2+b2+2abcos⁡π2
A=a2+b2

Since the frequency for both motion are same, then the resultant motion will be SHM.

Topic: Physics, Oscillations, NEET, NEET 2015 (Phase 1)
When two half-cells of electrode potential of E1o and E2o are combined to form a cell of electrode potential E3o(n1,n2,n3 are the number of electrodes exchanged in first, second and third half-cell reactions), then

Options:
A E3o=E1o+E2o
B E3o=E2o-E1o
C E3o=n1E1o+n2E2on3
D E3o=n1E1o-n2E2on32

The correct answer is:
E3o=n1E1o+n2E2on3

Solution:
As E° is non additive but ΔG° is additive
ΔG3o=ΔG1o+ΔG2o
-n3FE3o=-nFE1o-n2FE2o
E3o=n1E1o+n2E2on3

Topic: Chemistry, Electrochemistry, NEET
When two identical solid balls, one made of ivory and the other of wet clay, are dropped from the same height onto the floor, which one will rise to a greater height after striking the floor and why?

Options:
A The ivory ball, as it is more elastic than the wet-clay ball.
B The wet-clay ball, as it has a higher density than the ivory ball.
C The wet-clay ball, as it absorbs more energy during the collision.
D The ivory ball, as it has a lower mass compared to the wet-clay ball.

The correct answer is:
The ivory ball, as it is more elastic than the wet-clay ball.

Solution:
Correct Option is : (A)
The ivory ball, as it is more elastic than the wet-clay ball.

Topic: Chemistry, Mechanical Properties of Solids, NEET
When two mercury droplets of radii 0.1 cm and 0.2 cm collapse into a single drop, what amount of energy is released? Given that the surface tension of mercury, T, is 435.5 × 10−3N m−1.

Options:
A 28 × 10−7J
B −32 × 10−7J
C 48 × 10−7J
D −52 × 10−7J

The correct answer is:
−32 × 10−7J

Solution:
Correct Option is : (B)
−32 × 10−7J

Topic: Chemistry, Mechanical Properties of Fluids, NEET
When two moles of hydrogen expands isothermally against a constant pressure of 1 atm, at 25℃ from 15 L to 50 L, the work done (in litre atm) will be-

Options:
A -17.5
B -35
C -51.5
D -70

The correct answer is:
-35

Solution:
p=1 atm
âV=50-15=35 L
â´ W=-p.âV=-1Ã35
=-35 Latm
Hence, work done by the system on the surroundings is equal to 35 L-atm.

Topic: Chemistry, Thermodynamics (C), NEET
When two monochromatic lights of frequency, ν and ν2 are incident on a photoelectric metal, their stopping potential becomes VS2 and Vs respectively. The threshold frequency for this metal is:

Options:
A 3ν
B 23ν
C 32ν
D 2ν

The correct answer is:
32ν

Solution:
Using Einstein's photoelectric equation we can write,

For first case:

hν=ϕ+eVS2 ...1

For second case:

hν2=ϕ+eVS ...2

Using value of eVS from equation(2) in equation(1), we can write,

hν=ϕ+12hν2-ϕ
⇒hν=ϕ+hν4-ϕ2
⇒ϕ2=3hν4
⇒ϕ=3hν2

As we know, ϕ=hν0

Therefore, ν0=3ν2

Topic: Physics, Dual Nature of Matter, NEET, NEET 2022 (Phase 1)
When two pure pea plants one having round seeds and the other having wrinkled seeds are crossed, their offsprings have

Options:
A Large starch grain
B Small starch grain
C Intermediate starch grain
D Large starch grain and intermediate starch grain is equal proportion

The correct answer is:
Intermediate starch grain

Solution:
The gene which controls starch synthesis in pea also controls the shape of the seeds. Thus, it is a pleiotropic gene. The dominant allele B and recessive allele is b.
BB: Round seeds with large starch grain
Bb: Round seeds with intermediate starch grain
bb: wrinkled seeds with small starch grain
Thus, if the shape of seed is considered as the phenotype, alleles show complete dominance, whereas for starch grain, it shows incomplete dominance. In the given example, BB x bb produces Bb which are all heterozygotes having round seeds with intermediate starch grain.

Topic: Biology, Principles of Inheritance and Variation, NEET
When two reactants A and B are mixed to give products C and D, the reaction quotient Q at the initial stage of the reaction is best described by-

Options:
A Is independent of time
B Increases with time
C Decreases with time
D Is zero

The correct answer is:
Increases with time

Solution:
Q = Reaction quotient Q ≠ K c
Q = Concentration of products x Concentration of reactant y
Initially concentration of products is low Q < KC and Q then increases with time till it becomes equal to KC

Topic: Chemistry, Chemical Equilibrium, NEET
When two resistances R1 and R2 are connected in series, they consume 12 W powers. When they are connected in parallel, they consume 50 W powers. What is the ratio of the powers of R1 and R2?

Options:
A 14
B 4
C 32
D 3

The correct answer is:
32

Solution:
In series,
Ps=P1 ÃP2P1+P2=12 W
In parallel, Pp=P1+P2=50 W
â´ P1P2=12Ã50=600
Now, P1-P22=P1+P22-4P1P2
=502-4Ã600
=2500-2400=100
â´ P1-P2=10
Or P1=30 W, P2=20 W
â´ P1P2=32

Topic: Physics, Current Electricity, NEET
When two species of different genealogy come to resemble each other as a result of adaptation, the phenomenon is termed:

Options:
A microevolution
B co-evolution
C convergent evolution
D divergent evolution.

The correct answer is:
convergent evolution

Solution:
The analogous organs show convergent evolution due to similar adaptions which do not support organic evolution. Divergent evolution occurs when two groups of the same species evolve different traits within those groups in order to accommodate for differing environmental and social pressures. Microevolution is the change in allele frequencies that occurs over a relatively short period of time within a population. This change is due to four different processes: mutation, selection, gene flow and genetic drift. Coevolution refers to the evolution of at least two species, which occurs in a mutually dependent manner.
Related Theory
As bat's wing and bird's wing have similar structure and origin i.e., they have bony structures hence, they are called homologous organs, showing divergent evolution. Bat's wing is analogous to the wing of an insect, because the wing of an insect does not have a bony structure, it has membranous wing. So bat's wing and insect's wing are analogous showing convergent evolution, because they have similar functions but do not have the same origin and structure.

Topic: Biology, Evolution, NEET, NEET 2007
When two unrelated individuals or lines are crossed, the performance of $F_1$ hybrid is often superior to both its parents. This phenomenon is called

Options:
A transformation
B splicing
C metamorphosis
D heterosis

The correct answer is:
heterosis

Solution:
The superiority of hybrids over either of the parents (dominante or recessive is called hybrid vigour (G. Shull). Heterosis is equivalent of hybrids vigour.

Topic: Biology, Principles of Inheritance and Variation, NEET, NEET 2011 (Screening)
When two unrelated individuals or lines are crossed, the performance of the F1 hybrid is often superior to both its parents. This phenomenon is called

Options:
A Transformation
B Splicing
C Metamorphosis
D Heterosis

The correct answer is:
Heterosis

Solution:
Superiority of hybrid over its parent is called as hybrid vigour or heterosis. The term was coined by Shull. It occurs due to heterozygosity of hybrids.

Topic: Biology, Principles of Inheritance and Variation, NEET
When U 238 nucleus, originally at rest, decays by emitting an alpha particle having a speed u, the recoil speed of the residual nucleus is

Options:
A 2u238
B 3u234
C 4u234
D 5u238

The correct answer is:
4u234

Solution:
Apply conservation of linear momentum
= 0 = 4 uâ¡ - 2 3 4 vâ¡
â vâ¡ = 4 uâ¡ 2 3 4
The residual nucleus will recoil with a velocity of 4 uâ¡ 2 3 4 unit
Recoil speed of residual nucleus is 4 uâ¡ 2 3 4

Topic: Physics, Nuclear Physics, NEET
When ultraviolet radiation is incident on a surface, no photoelectrons are emitted. If a second beam causes photoelectrons to be ejected, it may consist of

Options:
A Infra - red waves
B X - rays
C Visible light rays
D Radio waves

The correct answer is:
X - rays

Solution:
Energy of photon of X - rays is more than energy of photon of ultraviolet rays. Because frequency of x rays is more than ultraviolet rays.

Topic: Physics, Dual Nature of Matter, NEET
When ultraviolet rays incident on metal plate then the photoelectric effect does not occur, it occurs by incidence of:

Options:
A infrared rays
B X-rays
C radio wave
D light wave

The correct answer is:
X-rays

Solution:
When ultraviolet rays are incident on the metal plate and photoelectric effect does not occur, It means that the threshold frequency is greater than the frequency of ultra-violet rays. X-rays have extremely higher frequencies compared to that of ultra-violet rays. For photoelectric effect, the frequency of the incident light must be greater than the threshold frequency of the metal. Hence, when X-rays are incident, photoelectric emission happens. The correct option is B.

Topic: Physics, Dual Nature of Matter, NEET, NEET 2002
When unpolarised light beam is incident from air onto glass at polarising angle

Options:
A reflected light is polarised 100%
B reflected & refracted beams are partially polarized
C reflected & refracted beams are completely polarised
D refracted light is polarised 100%

The correct answer is:
reflected light is polarised 100%

Solution:
From Bragg's law when unpolarised light beam is incident from air onto glass at polarising angle
reflected light is 100% polarised.

Topic: Physics, Wave Optics, NEET
When unpolarized light beam is incident from air onto glass (n=1.5) at the polarising angle

Options:
A reflected beam is polarised 100 percent
B reflected and refracted beams are partially polarised
C the reason for reflected beam getting 100% polarised is that almost all the light is reflected
D all of the above

The correct answer is:
reflected beam is polarised 100 percent

Solution:
If unpolarised light is incident at polarising angle, then reflected light is completely, i.e. 100% polarised.

Topic: Physics, Wave Optics, NEET
When vapour condenses into liquid

Options:
A it absorbs heat
B it liberates heat
C its temperature increases
D its temperature decreases

The correct answer is:
it liberates heat

Solution:
In vapour to liquid phase transition, heat is liberated.

Topic: Physics, Thermal Properties of Matter, NEET
When was Crick made an F.R.S.?

Options:
A 1950
B 1953
C 1954
D 1959

The correct answer is:
1959

Solution:
Crick was made an F.R.S. in 1959.

Topic: Biology, Principles of Inheritance and Variation, NEET
When was Mendeleev's Periodic Table published?

Options:
A 1805
B 1869
C 1905
D 1920

The correct answer is:
1905

Solution:
Mendeleev's Periodic Table was published in 1905.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
When was the collection carried out that showed a reversal in the proportion of white:winged and dark-winged moths?

Options:
A 1850s
B 1920s
C 1980s
D 2000s

The correct answer is:
1920s

Solution:
The collection carried out after industrialisation, i.e., in 1920, showed a reversal in the proportion of white:winged and dark-winged moths.

Topic: Biology, Evolution, NEET
When was the discovery of nuclein made?

Options:
A At the same time as the proposition of principles of inheritance by Mendel
B Before the discovery of the principles of inheritance by Mendel
C After the discovery of the principles of inheritance by Mendel
D In the 20th century

The correct answer is:
At the same time as the proposition of principles of inheritance by Mendel

Solution:
The discovery of nuclein by Meischer and the proposition for principles of inheritance by Mendel were almost at the same time.

Topic: Biology, Molecular Basis of Inheritance, NEET
When was the question of what molecule was the genetic material answered?

Options:
A By 1926
B In 1928
C After 1928
D Not answered

The correct answer is:
Not answered

Solution:
The question of what molecule was actually the genetic material had not been answered by 1926.

Topic: Biology, Molecular Basis of Inheritance, NEET
When water is added to compound (A) of calcium, solution of compound (B) is formed. When carbon dioxide is passed into the solution, it turns milky due to the formation of compound (C). If excess of carbon dioxide is passed into the solution milkiness disappears due to the formation of compound (D). Identify the compounds A, B, C and D Which compounds correspond to A, B, C, and D in the following chemical reactions?

Options:
A A = Calcium hydroxide, B = Calcium hydroxide, C = Calcium bicarbonate, D = Calcium chloride
B A = Calcium oxide, B = Calcium sulfate, C = Calcium carbonate, D = Calcium chloride
C A = Calcium chloride, B = Calcium carbonate, C = Calcium chloride, D = Calcium bicarbonate
D A = Calcium sulfate, B = Calcium carbonate, C = Calcium bicarbonate, D = Calcium chloride

The correct answer is:
A = Calcium hydroxide, B = Calcium hydroxide, C = Calcium bicarbonate, D = Calcium chloride

Solution:
Correct Option is : (A)
A = Calcium hydroxide, B = Calcium hydroxide, C = Calcium bicarbonate, D = Calcium chloride

Topic: Chemistry, s Block Elements, NEET
When we homogenise any tissue in acid the acid-soluble pool represents

Options:
A Cytoplasm
B Cell membrane
C Nucleus
D Mitochondria

The correct answer is:
Cytoplasm

Solution:
When we homogenise any tissue in acid the acid-soluble pool represents Cytoplasm.

Topic: Biology, Biomolecules (B), NEET
When we homogenise any tissue in an acid, the acid-soluble pool represents:

Options:
A Cytoplasm
B Macromolecules
C Nucleus
D Mitochondria

The correct answer is:
Cytoplasm

Solution:
The acid soluble pool has a roughly similar composition as that of cytoplasm. Biomolecules with molecular weights in the range of 18 - 800 Daltons come in the acid- soluble fraction (with the exception of lipids). Though, the macromolecules from cytoplasm and organelles represent the acid-insoluble fraction.

Topic: Chemistry, Biomolecules, NEET
When we ligate a foreign DNA at the SalI site of pBR322, the ___a___ plasmid will lose tetracycline resistance due to the insertion of foreign DNA but can still be selected out from ___b___ ones by plating the ___c___ on ampicillin containing medium.

Options:
A A = Non-recombinant , B = Recombinant , C = Transformant
B A = Recombinant , B = Non-recombinant , C = Transformant
C A = Transformant , B = Non-recombinant , C = Recombinant
D A = Recombinant , B = Transformant , C = Non-recombinant

The correct answer is:
A = Recombinant , B = Non-recombinant , C = Transformant

Solution:
pBR322 is an E.coli plasmid that contains origin of replication, ampicillin-resistant gene, tetracycline resistance gene, and multiple cloning site. It is a highly studied plasmid vector. Because it has two resistance genes, transformed cells can be screened from non-transformed by process of insertional inactivation in which target DNA when inserted into tetracycline gene, disrupt the gene and making cell recombinant with resistance to ampicillin only. Hence, colonies formed on the ampicillin plate are those which contain target DNA.

Topic: Biology, Biotechnology - Principles and Processes, NEET
When we look at stars in a clear night sky, what are we doing?

Options:
A Looking into the future
B Looking into the present
C Looking back in time
D Seeing things that are not there

The correct answer is:
Looking back in time

Solution:
When we look at stars on a clear night sky, we are looking back in time because the light emitted by the stars began its journey millions of years ago.

Topic: Biology, Evolution, NEET
When were sea weeds and few plants existed?

Options:
A 500 million years ago
B 350 million years ago
C 320 million years ago
D 250 million years ago

The correct answer is:
320 million years ago

Solution:
Sea weeds and few plants existed probably around 320 million years ago.

Topic: Biology, Evolution, NEET
When will maximum work be obtained from a galvanic cell?

Options:
A When the cell is short-circuited.
B When the cell has reached equilibrium.
C When the cell voltage is zero.
D The maximum work can be obtained from a galvanic cell when the charge is passed reversibly.

The correct answer is:
The maximum work can be obtained from a galvanic cell when the charge is passed reversibly.

Solution:
Correct Option is : (D)
The maximum work can be obtained from a galvanic cell when the charge is passed reversibly.

Topic: Chemistry, Electrochemistry, NEET
When will the chloroplasts align with their flat surfaces parallel to the walls?

Options:
A When they are perpendicular to the incident light
B When they get the optimum quantity of incident light
C When the mesophyll cells align them along the walls
D When they are directly light driven

The correct answer is:
When they get the optimum quantity of incident light

Solution:
The chloroplasts align themselves along the walls of the mesophyll cells so that they receive the optimum amount of incident light.

Topic: Biology, Photosynthesis in Higher Plants, NEET
When will the motion of a simple pendulum be simple harmonic?

Options:
A When the length of the pendulum is small
B When the amplitude of oscillation is large
C When the restoring force is constant
D When the bob of the pendulum is displaced from the mean position so that sinθ ≅ θ

The correct answer is:
When the bob of the pendulum is displaced from the mean position so that sinθ ≅ θ

Solution:
Correct Option is : (D)
When the bob of the pendulum is displaced from the mean position so that sinθ ≅ θ

Topic: Chemistry, Oscillations, NEET
When will the population density increase, under special conditions?
When the number of :

Options:
A Deaths exceeds number of births and also number of emigrants equals number of immigrants.
B Births plus number of immigrants equals number of deaths plus number of emigrants.
C Births plus number of emigrants is more than the number of deaths plus number of immigrants.
D Births plus number of immigrants is more than the sum of number of deaths and number of emigrants.

The correct answer is:
Births plus number of immigrants is more than the sum of number of deaths and number of emigrants.

Solution:
$(\mathrm{N})$ is the population density at time t , then its density at time $\mathrm{t}+1$ is
$\mathrm{Nt}_{\mathrm{t}}+1=\mathrm{N}+[(B+\mathrm{I})-(\mathrm{D}+\mathrm{E})]$
Population density will increase if the number of births plus the number of immigrants $(\mathrm{B}+\mathrm{I})$ is more than the number of deaths plus the number of emigrants ( $D+E)$.

Topic: Biology, Organisms and Populations, NEET, NEET 2024 (Re-NEET)
When work is done on a system, how does it affect the internal energy of the system?

Options:
A Increases the internal energy
B Decreases the internal energy
C Has no effect on the internal energy
D Changes the composition of the internal energy

The correct answer is:
Increases the internal energy

Solution:
When work is done on a system, it increases the internal energy of the system.

Topic: Chemistry, Thermodynamics (C), NEET
When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?

Options:
A Falling O2 concentration
B Rising CO2 concentration
C Falling CO2 concentration
D Rising CO2 and falling O2 concentration

The correct answer is:
Rising CO2 concentration

Solution:
The rise in CO2 concentration stimulates chemoreceptors present in the aorta and carotid artery, which stimulates the respiratory centre. The respiratory centre is not directly sensitive to oxygen concentration & hence desire to breathe is induced by rising in CO2 the concentration of blood.

Topic: Biology, Breathing and Exchange of Gases, NEET, NEET 2015 (Phase 1)
When you take cells or tissue pieces and grind them with an acid in a mortar and pestle, all the small biomolecules dissolve in the acid. Proteins, polysaccharides and nucleic acids are insoluble in mineral acid and get precipitated. The acid-soluble compounds include amino acids, nucleosides, small sugars etc. When one adds a phosphate group to a nucleoside, one gets another acid-soluble biomolecule called

Options:
A Nitrogen base
B Adenine
C Sugar phosphate
D Nucleotide

The correct answer is:
Nucleotide

Solution:
When one adds a phosphate group to a nucleoside, one gets another acid-soluble biomolecule called Nucleotide.

Topic: Biology, Biomolecules (B), NEET
When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water, the sodium ions are exchanged with

Options:
A H+ions
B Ca2+ions
C Mg2+ions
D Both Ca2+ and Mg2+

The correct answer is:
Both Ca2+ and Mg2+

Solution:
Zeolite when treated with hard water exchange Ca+2 and Mg+2 ions (present in hard water) with Na+ ions.

Topic: Chemistry, s Block Elements, NEET