datavorous/entrance-exam-dataset huggingface dataset:
What do you understand by the term" nonstoichiometric hydrides" ? Do you expect this type of the hydrides to be formed by alkali metals ? Justify your answer.

Options:

None

Solution:
Hydrides which are deficient in hydrogen and in which the ratio of the metal to hydrogen is fractional are called non-stoichiometric hydrides. Furthermore, this fractional ratio is not fixed but varies with the temperature and the pressure. These type of hydrides are formed by \(d\)-and \(f\) block elements. In these hydrides, the hydrogen atoms occupy holes in the metal lattice. Usually some holes always remain unoccupied and hence these metals form non-stoichiometric hydrides. Since alkali metals are highly reducing, they transfer their lone electron to the \(\mathrm{H}\) atom, thereby forming \(\mathrm{H}^{-}\)ions. In other words, alkali metal hydrides are ionic in which \(\mathrm{H}^{-}\)ions occupy holes in the lattice. Since a hydride ion is formed by complete transfer of an electron, therefore, the ratio of metal to hydrogen is always fixed and hence alkali metals form only stoichiometric hydrides. In other words, alkali metals do not form non-stoichiometric hydrides.

Topic: Chemistry, Hydrogen
What does a disturbance in genetic equilibrium indicate according to Hardy-WeinbergWeinberg principle?

Options:
A The population is in a state of balance
B The population is evolving
C The population is experiencing genetic drift
D The population is experiencing migration

The correct answer is:
The population is evolving

Solution:
Hardy-WeinbergWeinberg equilibrium states that the frequency of alleles in a population should remain constant unless acted upon by external forces. If the frequency of alleles deviates from the expected values, it indicates that the population is undergoing evolutionary change.

Topic: Biology, Evolution, NEET
What does an aqueous solution of sodium chloride mainly contain?

Options:
A Sodium ions and chloride ions
B Unionized sodium chloride molecules
C Acetate ions and hydronium ions
D Acetic acid molecules

The correct answer is:
Sodium ions and chloride ions

Solution:
The paragraph mentions that an aqueous solution of sodium chloride is comprised entirely of sodium ions and chloride ions.

Topic: Chemistry, Ionic Equilibrium, NEET
What does Charles' law state about the relationship between the volume of a gas and its temperature?

Options:
A Volume is inversely proportional to temperature.
B Volume is directly proportional to absolute temperature.
C Volume remains constant with temperature changes.
D Volume decreases as temperature decreases.

The correct answer is:
Volume is directly proportional to absolute temperature.

Solution:
Charles' law states that, with pressure remaining constant, the volume of a fixed mass of a gas is directly proportional to its absolute temperature.

Topic: Chemistry, States of Matter, NEET
What does genetic engineering involve?

Options:
A Altering the chemistry of genetic material
B Maintaining a sterile environment for microbe growth
C Sequencing DNA and R
D Mapping genomes

The correct answer is:
Altering the chemistry of genetic material

Solution:
Genetic engineering involves the techniques to alter the chemistry of genetic material (DNA and RNA) to introduce these into host organisms and thus change the phenotype of the host organism.

Topic: Biology, Biotechnology - Principles and Processes, NEET
What does Le Chatelier's principle state about the composition of the equilibrium mixture when the concentration of reactants or products is changed?

Options:
A The composition remains unchanged.
B The composition changes in a random manner.
C The composition changes to minimize the effect of concentration changes.
D The composition always shifts towards more reactants.

The correct answer is:
The composition changes to minimize the effect of concentration changes.

Solution:
Le Chatelier's principle states that the composition of the equilibrium mixture changes to minimize the effect of concentration changes.

Topic: Chemistry, Chemical Equilibrium, NEET
What does LH stimulate in females?

Options:
A Androgen synthesis and secretion
B Spermatogenesis
C Ovulation of mature follicles
D Glucocorticoids synthesis and secretion

The correct answer is:
Ovulation of mature follicles

Solution:
LH stimulates ovulation of fully mature follicles (graafian follicles) and maintains the corpus luteum, formed from the remnants of the graafian follicles after ovulation in females.

Topic: Biology, Chemical Coordination and Integration, NEET
What does not change in the field of central force

Options:
A Potential energy
B Kinetic energy
C Linear momentum
D Angular momentum

The correct answer is:
Angular momentum

Solution:
For central force, torque is zero.
$\tau=\frac{d L}{d t}=0 \quad \Rightarrow L=$ constant i.e. Angular momentum is constant.

Topic: Physics, Gravitation, JEE Main
What does phloem translocate in higher plants?

Options:
A Only water and mineral salts
B Organic and inorganic solutes
C Hormones from aerial parts to roots
D None of the above

The correct answer is:
Organic and inorganic solutes

Solution:
Phloem translocates a variety of organic and inorganic solutes, mainly from the leaves to other parts of the plants.

Topic: Biology, Transport in Plants, NEET
What does the dorsal portion of the midbrain mainly consist of?

Options:
A Corpora quadrigemina
B Fibre tracts
C Convoluted surface
D Respiratory centres

The correct answer is:
Corpora quadrigemina

Solution:
The dorsal portion of the midbrain consists mainly of four round swellings (lobes) called corpora quadrigemina.

Topic: Biology, Neural Control and Coordination, NEET
What does the filiform apparatus do at the entrance into ovule?

Options:
A It guides pollen tube from a synergid to egg
B It helps in the entry of pollen tube into a synergid
C It prevents entry of more than one pollen tube into the embryosac
D It brings about opening of the pollen tube

The correct answer is:
It helps in the entry of pollen tube into a synergid

Solution:
It helps in the entry of pollen tube into synergid : Filiform apparatus is present at the micropylar end in synergid. It is a mass of finger like projections. It releases certain chemical substances which direct the path of pollen tube inside the synergid through micropyle (chemotropic effect)

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET, NEET 2008 (Mains)
What does the Hardy-WeinbergWeinberg principle state about allele frequencies in a population?

Options:
A They are unstable and constantly changing from generation to generation.
B They are stable and remain constant from generation to generation.
C They are only present in certain generations and not others.
D They are only found in certain populations and not others.

The correct answer is:
They are stable and remain constant from generation to generation.

Solution:
The Hardy-WeinbergWeinberg principle states that allele frequencies in a population are stable and remain constant from generation to generation, meaning that the gene pool (total genes and their alleles in a population) remains constant.

Topic: Biology, Evolution, NEET
What does the Hardy-WeinbergWeinberg principle state about the gene pool in a population?

Options:
A It changes from generation to generation.
B It remains constant from generation to generation.
C It is only present in certain populations and not others.
D It is only present in certain generations and not others.

The correct answer is:
It remains constant from generation to generation.

Solution:
The Hardy-Weinberg principle states that the gene pool in a population remains constant from generation to generation, meaning that the allele frequencies in a population are stable.

Topic: Biology, Evolution, NEET
What does the modem do?

Options:
A Modulation
B Demodulation
C Both modulation and demodulation
D Neither modulation nor demodulation

The correct answer is:
Both modulation and demodulation

Solution:
Modem stands for modulation demodulation. Modem does both modulation and demodulation electrical signals sent through phone lines, coaxial cables, or other types of wiring. It can translate incoming analog signals back into digital data and convert the digital signal into analog as well.

Topic: Physics, Communication System, JEE Main
What does the study of fossils indicate about the history of life on Earth?

Options:
A That life:forms have remained unchanged throughout time
B That certain life forms are restricted to certain geological timespans
C That new forms of life have arisen at different times
D That fossils are only found in certain regions of the Earth

The correct answer is:
That certain life forms are restricted to certain geological timespans

Solution:
The study of fossils shows that certain life forms are restricted to certain geological timespans, and that new forms of life have arisen at different times in the history of Earth.

Topic: Biology, Evolution, NEET
What does the term "dynamic equilibrium" refer to in the context of chemical reactions?

Options:
A The point when the reaction just starts
B The point when reactants are completely consumed
C The point when reactant and product concentrations remain constant
D The point when reactants and products are rapidly changing

The correct answer is:
The point when reactant and product concentrations remain constant

Solution:
Dynamic equilibrium refers to the stage when the concentrations of reactants and products remain constant.

Topic: Chemistry, Chemical Equilibrium, NEET
What effect do the following processes have on the bond order in N2?

Options:
A Increase in B.O. of N2
B Decrease in B.O. of N2
C B.O. remains the same
D Cannot determine

The correct answer is:
Increase in B.O. of N2

Solution:
Correct Option is : (A)
Increase in B.O. of N2

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
What effect does the decomposition of ozone into oxygen have on entropy and enthalpy?

Options:
A Entropy increases, and enthalpy remains unchanged
B Both entropy and enthalpy increase
C Both entropy and enthalpy decrease
D Entropy increases, and enthalpy decreases

The correct answer is:
Both entropy and enthalpy increase

Solution:
The decomposition of ozone into oxygen results in an increase in entropy (∆S is positive) and liberation of heat (∆H is negative), which leads to both entropy and enthalpy increasing.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
What effect would occur if a 3 mm thick mica sheet (with a dielectric constant of 6) were inserted between the plates of a parallel plate capacitor with air between the plates, where each plate has an area of 6 × ${{10}^{-3}}$m² and the distance between the plates is 3 mm, while the voltage supply remained connected? Options:

Options:
A The capacitance would increase.
B The capacitance would decrease.
C The voltage across the plates would increase.
D The voltage across the plates would decrease.

The correct answer is:
The capacitance would increase.

Solution:
Correct Option is : (A)
The capacitance would increase.

Topic: Chemistry, Capacitance, NEET
What electronic transition in Li2+ produces the radiation of same wavelength as the first line in the Balmer's series of Hydrogen spectrum-

Options:
A n2=3 to n1=2
B n2=6 to n1=3
C n2=9 to n1=6
D n2=9 to n1=8

The correct answer is:
n2=9 to n1=6

Solution:
First line in balmer series means transition from n=3 to n=2. Now, 9th orbit of Li2+ has same energy as third orbit of ′H′ atom & 6th orbit of Li2+ has same energy as second orbit of ′H′ atom. So n=9 to n=6 transition in Li2+Â would have same wavelength as first line in balmer series of
H-spectrum.

Topic: Chemistry, Structure of Atom, JEE Main
What equal length of an iron wire and a copper-nickel alloy wire, each of 2 mm diameter connected parallel to give an equivalent resistance of 3 Ω?
(Given resistivities of iron and copper-nickel alloy wire are 12 μΩ cm and 51 μΩ cm respectively)

Options:
A 97 m
B 110 m
C 90 m
D 82 m

The correct answer is:
97 m

Solution:
R1R2R1+R2=3 Ω

ρ1ρ2ρ1+ρ2×ℓA=3 Ωℓ=3×A×ρ1+ρ2ρ1ρ2=3×π10−32×63×10−812×10-851×10−8ℓ≈97 m

Topic: Physics, Current Electricity, JEE Main, JEE Main 2021 (26 Aug Shift 1)
What final product will form when alcoholic KOH is treated with 1, 1-dichloroethane?

Options:
A Ethane-1, 2-diol
B Ethene
C Ethyne
D Acetaldehyde

The correct answer is:
Ethyne

Solution:

Topic: Chemistry, Haloalkanes and Haloarenes, JEE Main
What form does soap remain in after the saponification reaction?

Options:
A Liquid form
B Solid form
C Gaseous form
D Colloidal form

The correct answer is:
Colloidal form

Solution:
After the saponification reaction, soap remains in colloidal form.

Topic: Chemistry, Chemistry in Everyday Life, NEET
What generally happens to the rate of a reaction when the concentration of reactants increases?

Options:
A It remains constant
B It decreases
C It increases
D It becomes unpredictable

The correct answer is:
It increases

Solution:
Rates generally increase when reactant concentrations increase.

Topic: Chemistry, Chemical Kinetics, NEET
What gives aromatic character to the C60 molecule?

Options:
A Double bonds between carbon atoms
B Triple bonds between carbon atoms
C Delocalized electrons in molecular orbitals
D The presence of inert gases during formation

The correct answer is:
Delocalized electrons in molecular orbitals

Solution:
The remaining electron at each carbon in a C60 molecule is delocalized in molecular orbitals, which gives aromatic character to the molecule.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
What happened to the population of melanized moths in areas where industrialization did not occur?

Options:
A They increased in population size
B They decreased in population size
C They remained unchanged
D They became extinct

The correct answer is:
They decreased in population size

Solution:
In areas where industrialization did not occur e.g., in rural areas, the count of melanized moths was low.

Topic: Biology, Evolution, NEET
What happened when we inoculated Rhizobium in wheat field?

Options:
A No increase in production (nitrogen content of soil remains same)
B A lot of increase in production (nitrogen content of soil increases)
C Fertility of soil decreases
D Fertility of soil increases

The correct answer is:
No increase in production (nitrogen content of soil remains same)

Solution:
Rhizobium species is symbiotic nitrogen-fixing bacteria, which occurs in root nodules of legumes. When we inoculated Rhizobium in wheat field, there is no increase in production. Because wheat has no root nodules for fixing nitrogen content. Therefore, nitrogen content of soil will remain same.

Topic: Biology, Microbes in Human Welfare, JIPMER, JIPMER 2008
What happens after the rise in permeability to Na⁺ in a neuron?

Options:
A The permeability to K⁺ increases.
B The polarity of the membrane remains unchangeD)
C The resting potential of the membrane decreases
D The permeability to Na⁺ decreases

The correct answer is:
The permeability to K⁺ increases.

Solution:
The rise in permeability to Na⁺ is short-lived and is followed by a rise in permeability to K⁺. K⁺ diffuses outside the membrane, restoring the resting potential of the membrane.

Topic: Biology, Neural Control and Coordination, NEET
What happens during Anaphase 1 of meiosis?

Options:
A Bivalent chromosomes align on the equatorial plate.
B Homologous chromosomes separate.
C Sister chromatids remain associated at their centromeres.
D Microtubules from the opposite poles of the spindle attach to the kinetochore of homologous chromosomes.

The correct answer is:
Homologous chromosomes separate.

Solution:
During Anaphase 1, the homologous chromosomes separate, while sister chromatids remain associated at their centromeres.

Topic: Biology, Cell Cycle and Cell Division, NEET
What happens during fertilization in humans after many sperms reach close to the ovum?

Options:
A Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida
B All sperms except the one nearest to the ovum lose their tails
C Cells of corona radiata trap all the sperms except one
D Only two sperms nearest the ovum penetrate zona pellucida

The correct answer is:
Secretions of acrosome helps one sperm enter cytoplasm of ovum through zona pellucida

Solution:
The process of fusion of a sperm with an ovum is called fertilization. During fertilization, a sperm comes in contact with the zona pellucida layer of the ovum and induces changes in the membrane that blocks the entry of additional sperms. Thus, it ensures that only one sperm can fertilize an ovum. The secretions of the acrosome help the sperm enter into the cytoplasm of the ovum through the zona pellucida and the plasma membrane.

Topic: Biology, Human Reproduction, NEET, NEET 2011 (Mains)
What happens during Metaphase 1 of meiosis?

Options:
A Homologous chromosomes separate.
B Bivalent chromosomes align on the equatorial plate.
C Sister chromatids remain associated at their centromeres.
D Microtubules from the opposite poles of the spindle attach to the kinetochore of homologous chromosomes.

The correct answer is:
Bivalent chromosomes align on the equatorial plate.

Solution:
During Metaphase 1, the bivalent chromosomes align on the equatorial plate.

Topic: Biology, Cell Cycle and Cell Division, NEET
What happens during regulation action of a Zener diode?

Options:
A The current and voltage acorss the Zener remains fixed

B
The current through the serious Resistance $\left(\mathrm{R}_{\mathrm{s}}\right)$ changes

C
The Zener resistance is constant

D
The resistance offered by the Zener changes

The correct answers are:
The current through the serious Resistance $\left(\mathrm{R}_{\mathrm{s}}\right)$ changes
,
The resistance offered by the Zener changes

Solution:
During action of regulation of a Zener diode, the current through the $R_{\mathrm{s}}$ changes and resistance offered by the Zener diode changes the current through the zener charges but the voltage across the Zener remains constant.

Topic: Physics, Semiconductors
What happens if the female bee's colour patterns change during evolution?

Options:
A The orchid flower will co:evolve to maintain the resemblance of its petal to the female bee.
B The bee will stop 'pseudocopulating' with the orchid flower.
C The pollination success will increase.
D The pollination success will remain unchanged.

The correct answer is:
The orchid flower will co:evolve to maintain the resemblance of its petal to the female bee.

Solution:
If the female bee's colour patterns change during evolution, the pollination success will be reduced unless the orchid flower co:evolves to maintain the resemblance of its petal to the female bee.

Topic: Biology, Organisms and Populations, NEET
What happens if we increase temperature of a chemisorption process

Options:
A Rate of chemisorption increases
B Rate of chemisorption decreases
C Rate remains same
D Cannot say

The correct answer is:
Rate of chemisorption increases

Solution:
Correct Option is : 1
Rate of chemisorption increases

Topic: Chemistry, Surface Chemistry, NEET
What happens in the excited state of a Be atom to account for its bivalency?

Options:
A One 2s-electron is promoted to the 2p orbital.
B One 2s-electron is promoted to the 3s orbital.
C One 2s-electron is promoted to the 2d orbital.
D The 2s-electron remains in the same orbital.

The correct answer is:
One 2s-electron is promoted to the 2p orbital.

Solution:
In the excited state of a Be atom, one of the 2s-electrons is promoted to a vacant 2p orbital to account for its bivalency.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
What happens to a cell during M phase of cell cycle?

Options:
A Nucleocytoplasmic index decreases.
B Nucleocytoplasmic index increases.
C Nucleocytoplasmic index fluctuates.
D Nucleocytoplasmic index remains constant.

The correct answer is:
Nucleocytoplasmic index decreases.

Solution:
During $G_1$ phase, the cell is in resting state and the nucleocytoplasmic index is stable. During the $\mathrm{S}$ phase of the cell cycle, DNA replicates, consequently nucleocytoplasmic index increases due to increase in nuclear volume. During $G_2$ phase, the cell is again stable. During M phase, nucleocytoplasmic index decreases. After $M$ phase or mitosis when the cell divides, nucleoplasmic index returns to normal.

Topic: Biology, Cell Cycle and Cell Division, AIIMS, AIIMS 2019 (26 May)
What happens to a particle of total energy 1 J moving under the potential V(x) = (0.5 N/m^(-1))x^2/2 when it reaches x = ± 2 m?

Options:
A It will continue to move indefinitely in the same direction.
B It will come to a stop at x = ± 2 m and remain there.
C It will turn back when it reaches x = ± 2 m.
D It will accelerate when it reaches x = ± 2 m.

The correct answer is:
It will turn back when it reaches x = ± 2 m.

Solution:
Correct Option is : (C)
It will turn back when it reaches x = ± 2 m.

Topic: Chemistry, Work Power Energy, NEET
What happens to a plant cell in a hypertonic solution?

Options:
A The cell shrinks
B The cell swells
C The cell remains unchanged
D The cell plasmolyses

The correct answer is:
The cell shrinks

Solution:
In a hypertonic solution, the external solution is more concentrated than the cytoplasm, so water moves out of the cell causing it to shrink.

Topic: Biology, Transport in Plants, NEET
What happens to a plant cell in a hypotonic solution?

Options:
A The cell shrinks
B The cell swells
C The cell remains unchanged
D The cell plasmolyses

The correct answer is:
The cell swells

Solution:
In a hypotonic solution, the external solution is more dilute than the cytoplasm, so water moves into the cell causing it to swell.

Topic: Biology, Transport in Plants, NEET
What happens to a plant cell in a hypotonic solution?

Options:
A The cell shrinks
B The cell swells
C The cell remains unchanged
D The cell plasmolysed

The correct answer is:
The cell swells

Solution:
In a hypotonic solution, the external solution is more dilute than the cytoplasm. Therefore, water moves into the cell causing it to swell.

Topic: Biology, Transport in Plants, NEET
What happens to a plant cell in an isotonic solution?

Options:
A The cell shrinks
B The cell swells
C The cell remains unchanged
D The cell plasmolyses

The correct answer is:
The cell remains unchanged

Solution:
In an isotonic solution, the external solution balances the osmotic pressure of the cytoplasm, so there is no net flow of water towards the inside or outside, and the cell remains unchanged.

Topic: Biology, Transport in Plants, NEET
What happens to a sharp glass edge when heated up to its melting point in a flame?

Options:
A It becomes even sharper.
B It remains unchanged.
C It becomes smoother.
D It becomes brittle.

The correct answer is:
It becomes smoother.

Solution:
Correct Option is : (C)
It becomes smoother.

Topic: Chemistry, States of Matter, NEET
What happens to a system at equilibrium when the concentration of one or more reacting substances is changed?

Options:
A The system remains at equilibrium.
B The system shifts to a new equilibrium.
C The system is no longer at equilibrium, and a net reaction occurs.
D The system becomes highly unstable.

The correct answer is:
The system is no longer at equilibrium, and a net reaction occurs.

Solution:
When the concentration of one or more reacting substances in a system at equilibrium is changed, the system is no longer at equilibrium, and a net reaction takes place.

Topic: Chemistry, Chemical Equilibrium, NEET
What happens to alkaline earth metal nitrates when they are heated?

Options:
A They form water
B They decompose to give the respective metal oxide
C They produce nitrogen gas
D They remain unchanged

The correct answer is:
They decompose to give the respective metal oxide

Solution:
Upon heating, alkaline earth metal nitrates decompose to give the respective metal oxide and nitrogen dioxide gas.

Topic: Chemistry, s Block Elements, NEET