datavorous/entrance-exam-dataset huggingface dataset:
The number of contrasting characters studied by Mendel for his experiments was:

Options:
A 14
B 4
C 2
D 7

The correct answer is:
7

Solution:
Mendel conducted his historical experiments with Pisum sativum (garden pea) in the monastery garden between 1856-1864 and presented his work in the "Annual Proceedings of the Natural History Society of Brunn" in 1865. His paper was published next year in 1866. The characters studied by Mendel are:

Sr. No.	Character	Dominant trait	Recessive trait

1.	Seed shape	Round	Wrinkled

2.	Seed colour	Yellow	Green

3.	Flower colour	Violet/Red	White

4.	Pod shape	Full/Inflated	Constricted

5.	Pod colour	Green	Yellow

6.	Flower position	Axial	Terminal

7.	Stem height	Tall	Dwarf

Topic: Biology, Principles of Inheritance and Variation, NEET, NEET 2020 (Phase 2)
The number of d-electrons in Fe2+ (Z=26) is not equal to the number of electrons in which one of the following?

Options:
A s-electrons in Mg Z=12
B p-electrons in Cl Z=17
C d-electrons in Fe Z=26
D p-electrons in Ne Z=10

The correct answer is:
p-electrons in Cl Z=17

Solution:
26Fe2+⇒18Ar 3d6 ; 6 d-electrons
17Cl⇒1s2 2s2 2p6 3s2 3p5 ; 11 p-electrons
Mg=1s22s22p63s2 ; 6 s-electrons
d-electrons in Fe= 18Ar3d6=6
p-electrons in Ne=1s22s22p6=6

Topic: Chemistry, Structure of Atom, NEET, NEET 2015 (Phase 1)
The number of death and birth in the last stage of sigmoid growth curve of a population will be

Options:
A Similar to lag phase
B Unequal with more deaths
C Unequal with less deaths
D Equal

The correct answer is:
Equal

Solution:
The last stage of sigmoid growth curve is called the stationary phase or asymptote phase. It is observed on reaching the carrying capacity, where birth rate becomes equal to death rate.

Topic: Biology, Organisms and Populations, NEET
The number of d-electrons in Fe2+ (Z = 26) is not equal to the number of electrons in which one of the following?

Options:
A p-electrons in Cl (Z = 17)
B d-electrons in Fe (Z= 26)
C p-electrons in Ne (Z = 10)
D s-electrons in Mg (Z = 12)

The correct answer is:
p-electrons in Cl (Z = 17)

Solution:
Fe2+=3d6 (number of 'd' electrons = 6)
In Cl =1s22s22p62s23p5 (number of 'p' electrons = 12)
In Fe (number of 'd' electrons = 6) and in Mg ((number of 's' electrons = 6)

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
The number of electrons delivered at the cathode, during electrolysis by a current of 1 ampere in 60 seconds is (charge on electron =1.60×10-19 C)

Options:
A 6×1023
B 6×1020
C 3.75×1020
D 7.48×1023

The correct answer is:
3.75×1020

Solution:
Q=I×t
=1A×60s
=60 C
∴ Number of electrons =601.602×10-19
=3.75×1020

Topic: Chemistry, Electrochemistry, NEET, NEET 2016 (Phase 2)
The number of electrons donated from substance(s) getting oxidized to the substance(s) getting reduced in the chemical equation for the following reaction is:
Cr 2 O 7 2 - + Fe 2 + + C 2 O 4 2 - â Cr 3 + + Fe 3 + + CO 2 (Unbalanced)

Options:
A 6
B 5
C 3
D 4

The correct answer is:
6

Solution:
Writing the balanced oxidation and reduction half-reactions, making the number of electrons same in them and adding both half-reactions gives us the final balanced equation:

[Fe2++C2O42−  →  Fe3++2CO2+3e−]×2 (oxidation)

Cr2O72−+14H++6e−  →  2Cr3++7H2O (reduction)

On adding both the reactions, we get,

Cr2O72−+2Fe2++2C2O42−+14H+→2Cr3++2Fe3++4CO2+7H2O

Thus, 6 electrons are donated from oxidized substances to the reduced substance.

Topic: Chemistry, Redox Reactions, NEET
The number of electrons in Cl- ion are:

Options:
A 19
B 20
C 18
D 35

The correct answer is:
18

Solution:
The atomic number of chlorine is 17 and in Cl- ion, one extra electron is present. Thus, total no. of electrons=18.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
The number of electrons involve in the equation CrO42-→Cr2O72- is x . Then value of x is equal to

Options:
A 0
B 1
C 3
D 5

The correct answer is:
0

Solution:
C*rO42- C*r2O72-
x+[(-2)×4]=-2 2x+(-2)×7=-2
x=8-2=+6 2x=14-2=12 ,
x=122=+6
In this reaction oxidation and reduction are not involved because there is no change in oxidation number.

Topic: Chemistry, Redox Reactions, NEET
The number of electrons, protons and neutrons in a species are equal to 18, 16 and 16 respectively. What is the proper symbol to the species?

Options:
A (32S16)2-
B (32S16)4-
C (36S17)2-
D (36S18)2-

The correct answer is:
(32S16)2-

Solution:
Correct Option is : (A)
(32S16)2-

Topic: Chemistry, Structure of Atom, NEET
The number of ‘ends’ in a glycogen molecule would be

Options:
A Equal to the number of branches plus one
B Equal to the number of branch points
C One
D Two, one on the left side and another on the right side

The correct answer is:
Two, one on the left side and another on the right side

Solution:
The number of ‘ends’ in a glycogen molecule would be two, one on the left side and another on the right side.

Topic: Biology, Biomolecules (B), NEET
The number of Faradays required to reduce 4 g equivalent of Cu2+ to Cu metal will be

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

The correct answer is:
4

Solution:
Cu2+1mol+2e-2F→Cu
1 mole Cu2+=2 equivalent of Cu2+
or 2 equivalent of Cu2+ requires = 2F
So 4 equivalent of Cu2+ will require = 4 F

Topic: Chemistry, Electrochemistry, NEET
The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca=40 g mol–1) is

Options:
A 2
B 3
C 4
D 1

The correct answer is:
1

Solution:
Ca+2+2e-→Cas
Valency Factor =2
As per Faraday's 1st law, Charge passed in Faraday = Number of gram equivalent of product.
=2040×2=1F

Topic: Chemistry, Electrochemistry, NEET, NEET 2020 (Phase 1)
The number of genes on chromosome 1 is:

Options:
A 231
B 14
C 2968
D 3000

The correct answer is:
2968

Solution:
Chromosome 1 has most genes (2968), and the Y has the fewest (231).

Topic: Biology, Molecular Basis of Inheritance, NEET
The number of geometric isomers that can exist for square planar PtClpyNH3NH2OH+ is (py = pyridine):

Options:
A 6
B 2
C 3
D 4

The correct answer is:
3

Solution:
Complex with general formula [Mabcd]+ square planar complex can have three isomers.

Topic: Chemistry, Coordination Compounds, NEET
The number of gram molecules of oxygen in 6.02âÃâ 10 24 âCO molecules is

Options:
A

5 gm molecules

B

10 gm molecules

C

1 gm molecules

D

0.5 gm molecules

The correct answer is:

5 gm molecules

Solution:
6.02âÃâ 10 23 âmolecules of âCOâ=â1â mole of âCO
6.02âÃâ 10 24 âCOâmoleculesâ=â10â mole ofâCO
=â10âgâatoms ofâOâ=â5âgâ molecules of â O 2

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The number of hydrogen bonded water molecule(s) associated with $\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}$ is

Options:
A 3
B 1
C 2
D 5

The correct answer is:
1

Solution:
$\mathrm{Cu}^{2+}$ ion has 17 electrons in its outermost orbital. $4 \mathrm{H}_2 \mathrm{O}$ molecules donate 4 pairs of electrons for coordinate covalent sharing. The one $\mathrm{H}_2 \mathrm{O}$ molecule is attached to the sulphate ion by hydrogen bonding, the oxygen being oriented to the hydrated cupirc ion.
Thus, the number of hydrogen bonded water molecule associated with $\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}$ is 1 .

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET, NEET 2019 (Odisha)
The number of individuals of the population who left the habitat and gone elsewhere during the time period is called:

Options:
A immigration
B emigration
C migration
D all of these

The correct answer is:
emigration

Solution:
Mortality is the measure of death rate in a population whereas natality is the measure of birth rate for a given population.
The number of individual people who have entered a new population group from outside for a particular period of time is called immigration.
The number of individuals of the population who left the habitat and gone elsewhere during the time period is called emigration.

Topic: Biology, Organisms and Populations, NEET
The number of iodine atoms present in 1cm3 of its 0.1 M solution is

Options:
A 12.04×1023
B 6.02×1022
C 12.04×1019
D 6.02×1020

The correct answer is:
12.04×1019

Solution:
1000  cm 3  of 0.1 M solution≡0.1 mol  I 2
So 1  cm 3  of solution ≡ 0.1× 10 −3  mol  I 2
Hence 1 mol  I 2 contains =6.02× 10 23   I 2 molecules
So 0.1× 10 −3  mol  I 2 contains
=6.02× 10 23 ×0.1× 10 −3   I 2 molecules
=12.04× 10 19   I 2 atoms.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The number of isomers for the compound with molecular formula C 2 BrClFI is

Options:
A 3
B 4
C 5
D 6

The correct answer is:
6

Solution:

Topic: Chemistry, General Organic Chemistry, NEET
The number of isomers (including stereo) for the compound with molecular formula C2BrClFI is

Options:
A 2
B 4
C 6
D 8

The correct answer is:
6

Solution:
The compound with molecular formula C2BrClFI has following Six geometrical (E, Z type) isomer.

Topic: Chemistry, General Organic Chemistry, NEET
The number of isomers (including stereoisomers) of C5H10 are

Options:
A 10
B 11
C 12
D 13

The correct answer is:
13

Solution:

Topic: Chemistry, General Organic Chemistry, NEET
The number of isomers of the aromatic compound C8H10 is:

Options:
A 3
B 4
C 2
D 5

The correct answer is:
4

Solution:
(i) D.U=C+1−( H 2 )=8+1−( 10 2 )
=4
Total number of aromatic isomers = 4.

Topic: Chemistry, General Organic Chemistry, NEET
The number of linkage groups present in a diploid animal is

Options:
A equal to the total number of chromosomes
B half of the total number of chromosomes
C a quarter of the total number of chromosomes
D two- thirds of the total number of chromosomes

The correct answer is:
half of the total number of chromosomes

Solution:
The tendency of genes present on the same chromosome to be inherited together is called linkage. All the genes on a chromosome are said to be linked to one another and belong to the same linkage group. Number of linkage groups of a particular species corresponds to its haploid number of chromosomes or number of pairs of chromosomes. E.g. Pisum has 14 chromosomes thus it has seven linkage groups.

Topic: Biology, Principles of Inheritance and Variation, NEET
The number of manganese ions in tetrahedral and octahedral sites respectively in Mn3O4 are

Options:
A one Mn2+ and two Mn3+ ions
B one Mn3+ and two Mn2+ ions
C two Mn3+ and two Mn2+ ions
D two Mn2+ and one Mn3+ ions

The correct answer is:
one Mn2+ and two Mn3+ ions

Solution:
The number of manganese ions in tetrahedral and octahedral sites, respectively in Mn3O4 are one Mn2+ and two Mn3+ ions.
Mn3O4 has spinal type structure in which Mn2+ occupy 1/8 T.V. and Mn3+ occupy half of O.V.
Oxide ion has ccp arrangement (corner + face).

Topic: Chemistry, Solid State, NEET
The number of meso form of the given compound (A) is

Options:
A 2
B 3
C 4
D 8

The correct answer is:
2

Solution:
Number of meso form 2 ( nâ1 2 ) when compound is divisible into two identical halves and has odd number of chiral carbons.
m= 2 ( 3−1 2 )
=21=2 .

Topic: Chemistry, General Organic Chemistry, NEET
The number of metabolic steps required for the oxidation of glucose to form lactic acid

Options:
A 8
B 9
C 10
D 11

The correct answer is:
11

Solution:
Glucose first enter glycolysis to form pyruvic acid, this occurs in cytoplasm by most common pathway called EMP pathway. It is a 10 step pathway. Than pyruvic acid undergoes oxidation to form lactic acid in one step reaction. Thus total 11 steps occur for oxidation of glucose to form lactic acid.

Topic: Biology, Respiration in Plants, NEET
The number of mitotic generations required to form a mature embryo sac in most of the flowering plants is:

Options:
A One
B Two
C Three
D Four

The correct answer is:
Three

Solution:
From a single megaspore there is formation of 8 nucleate and 7 celled takes place, to start from single cell to 8 nucleate 7 celled there is three cycles of mitosis happens. This step result in the formation of the female gametophyte.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
The number of molecules in 100ml of 0.02 N H2SO4 is

Options:
A 6.02×1020
B 6.02×1016
C 6.02×1022
D 6.02×1021

The correct answer is:
6.02×1020

Solution:
Normality = Molarity × valency factor (n)
0.02=M×2
Molarity =No.ofmolesVolumeinlitre
0.01=n0.1=n=0.001
1 mole of H2SO4 contains 6.023×1023 molecules.
So, 0.001 mole contains 6.023×1020 molecules.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The number of moles $\mathrm{KMnO}_4$ that will be needed to react with one mole of sulphite ion in acidic solution is:

Options:
A $4 / 5$
B $2 / 5$
C 1
D $3 / 5$

The correct answer is:
$2 / 5$

Solution:
The balanced chemical equation is:
$2 \mathrm{MnO}_4^{-}+ 6 \mathrm{H}^{+}+5 \mathrm{SO}_3^{--} \longrightarrow 2 \mathrm{Mn}^{++}+5 \mathrm{SO}_4^{--}+3 \mathrm{H}_2 \mathrm{O}$
From the equation it is clear that
Moles of $\mathrm{MnO}_4^{-}$ require to oxidise 5 moles of $\mathrm{SO}_3^{--}$are 2
Moles of $\mathrm{MnO}_4^{-}$ require to oxidise 1 mole of $\mathrm{SO}_3^{--}$are $2 / 5$.

Topic: Chemistry, Redox Reactions, NEET, NEET 2007
The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber’s process is:

Options:
A 10
B 20
C 30
D 40

The correct answer is:
30

Solution:
Haber’s process N2g+3H2g⇌2NH3g

According to the reaction,

2 moles of ammonia are produced from 3 moles of H2

i.e., 1 mole of ammonia is produced from 32 moles of H2

Thus, 20 moles of ammonia =32×20=30 moles of H2

Hence, 30 moles is the correct option.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET, NEET 2019 (All India)
The number of moles of KMnO4 that will be needed to react with one mole of sulphite ion in acidic solution is

Options:
A 2/5
B 3/5
C 4/5
D 1

The correct answer is:
2/5

Solution:
2MnO4-+5SO32-+6H+â2Mn2++5SO42-+3H2O
As 5 moles sulphite ion reacts with 2 moles of MnO4-. So, 1 mole will reacts with 2/5 moles of MnO 4 â .

Topic: Chemistry, d and f Block Elements, NEET
The number of moles of KMnO4 that will be needed to react with one mole of sulphite ion in acidic solution is

Options:
A 25
B 1
C 45
D 35

The correct answer is:
25

Solution:
2MnO4-+6H++5SO32-→2Mn2++5SO42-+3H2O
5 mol SO32- require MnO4-=2 mol
1 mol S32- ions require MnO4-=25 mol.

Topic: Chemistry, d and f Block Elements, NEET
The number of moles of $\mathrm{KMnO}_4$ reduced by one mole of $\mathrm{KI}$ is alkaline medium is:

Options:
A one
B two
C five
D one fifth

The correct answer is:
two

Solution:
In alkaline medium:
Related Theory
In acidic medium: $\mathrm{MnO}_4^{-}+8 \mathrm{H}^{+}+5 e^{-} \longrightarrow$ $\mathrm{Mn}_2+4 \mathrm{H}_2 \mathrm{O}$
In basic medium: $\mathrm{MnO}_4^{-}+e^{-} \rightarrow \mathrm{MnO}_4^{2-}$
In neutral medium: $\mathrm{MnO}_4^{-}+4 \mathrm{H}^{+}+3 e^{-} \longrightarrow$ $\mathrm{MnO}_2+2 \mathrm{H}_2 \mathrm{O}$

Topic: Chemistry, Redox Reactions, NEET, NEET 2005
The number of N-CH2-N bonds in urotropine is

Options:
A 2
B 4
C 6
D 5

The correct answer is:
6

Solution:
Urotropine is hexamethylene tetramine (CH2)6N4 and have 6 N-CH2-N bonds.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
The number of nephrons present in a human being is about

Options:
A one lakh
B two lakhs
C ten lakhs
D twenty lakhs

The correct answer is:
twenty lakhs

Solution:
Nephrons are structural and functional units of the kidneys and humans have 2 kidneys. The studies show that the average number of the nephron is approximately 900,000 to 1 million per kidney. Hence, the numbers for nephrons present in an individual range from approximately 2,000,000 to >2.5 million.

Topic: Biology, Excretory Products and their Elimination, NEET
The number of nodal planes in a px orbital is

Options:
A One
B Two
C Three
D Zero

The correct answer is:
One

Solution:
Nodal plane is an imaginary plane on which probability of finding an electron is minimum. Every p-orbital has one nodal plane:

Topic: Chemistry, Structure of Atom, NEET
The number of nuclei of two radioactive substances is the same and their half-lives are 1 year and 2 years respectively. The ratio of their activities after 6 years will be

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

The correct answer is:
1 : 4

Solution:
N1=N01261=N064
N2=N01262=N08
A1A2=λ1N1λ2N2=T2T1.N1N2
A1A2=21×N064N08
A1A2=14

Topic: Physics, Nuclear Physics, NEET
The number of nucleotides present in the restriction sequence of the first restriction endonuclease is

Options:
A 6
B 8
C 12
D 16

The correct answer is:
12

Solution:
The first restriction endonuclease was HindII. It has a restriction site with 6 base pairs. Thus, it has 12 nucleotides.

Topic: Biology, Biotechnology - Principles and Processes, NEET
The number of occipital condyles in man is/are

Options:
A One
B Two
C Three
D Four

The correct answer is:
Two

Solution:
The skull region articulates with the superior region of the vertebral column with the help of two occipital condyles (dicondylic skull).

Topic: Biology, Locomotion and Movement, NEET
The number of octahedral void $(s)$ per atom present in a cubic close-packed structure is

Options:
A 1
B 3
C 2
D 4

The correct answer is:
1

Solution:
Number of octahedral voids $=$ number of atoms in the close packed structure.
Since, number of atoms $=1$
So, number of octahedral void $=1$

Topic: Chemistry, Solid State, NEET, NEET 2012 (Screening)
The number of orbitals associated with quantum numbers n=5,ms=+12 is

Options:
A 16
B 55
C 14
D 25

The correct answer is:
25

Solution:
Total 25 orbitals are possible

Topic: Chemistry, Structure of Atom, NEET
The number of oxygen atoms attached to each phosphorus atom in P4O10, is

Options:
A 2
B 2.5
C 3
D 4

The correct answer is:
4

Solution:
Structure of P4O10 is

Each phosphorus is attached to 4 oxygen atoms.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
The number of oxygen atoms in 4.4 g of CO2 is

Options:
A 1.2×1023
B 6×1022
C 6×1023
D 12×1023

The correct answer is:
1.2×1023

Solution:
Molar mass of CO2=12+32=44
âµ WM=Number of molecules NA for CO2
4.444=Number of molecules6Ã1023
â´ Number of molecules in C O 2 =4.4Ã6Ã102344
=0.1Ã6Ã1023=6Ã1022
Number of oxygen atoms =2 times of 6Ã1022
( âµ Each CO2 contains two oxygen atoms)
â´Number of oxygen atom =2Ã6Ã1022=1.2Ã1023

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The number of oxygen atoms in 4.4 of C O 2 is
(Given that atomic mass C and O are 12 and 16 g/mol )

Options:
A 1.2×10 23
B 1.2×10 24
C 6×10 22
D 6×10 23

The correct answer is:
1.2×10 23

Solution:
1âmolâ=6.023Ã 10 23 ââmolecules
4.4âgâC O 2 â=â 4.4 44 â=â0.1âmolâC O 2
(Mol. wt. of C O 2 â=â44â)
0.1âmolâ=6.023Ã 10 23 Ã0.1âmolecules
=â6âÃâ 10 22 âmolecules
=â2âÃâ6âÃâ 10 22 âatomsâofâO
= 1.2Ã10 23

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The number of parents involved in Apomixis and Amphimixis, respectively, are

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

The correct answer is:
1, 2

Solution:
Apomixis is the production of seeds without fertilization. It is a type of asexual reproduction which takes place when an organism produces its offsprings without exchanging any genetic details with another organism. There is no fusion taking place, so therefore only one parent gives rise to a new cell or organism resembling them in characteristics. Amphimixis involves fusion of gametes. This is a type of sexual reproduction which involves two different sexes which unite or fuse to form a new individual, who inherits the genes from both the parents.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
The number of peptide bond(s) in the following molecule is

Options:
A 3
B 2
C 1
D 0

The correct answer is:
2

Solution:
This compound has 2 peptide bonds.

Topic: Chemistry, Biomolecules, NEET
The number of phalanges in each limb of a human is ___.

Options:
A Ten
B Eleven
C Thirteen
D Fourteen

The correct answer is:
Fourteen

Solution:
The number of phalanges in each limb of a human is fourteen

Topic: Biology, Locomotion and Movement, NEET
The number of photoelectrons emitted for light of a frequency $v$ (higher than the threshold frequency $v_0$ ) is proportional to

Options:
A $v-v_0$
B threshold frequency $\left(v_0\right)$
C intensity of light
D frequency of light ( $v$ )

The correct answer is:
intensity of light

Solution:
The number of photoelectrons emitted is directly proportional to the intensity of light.

Topic: Physics, Dual Nature of Matter, NEET, NEET 2009 (Screening)
The number of photoelectrons emitted for the light of frequency υ (higher than the threshold frequency υ0) is proportional to

Options:
A threshold frequency (Ï0)
B intensity of light
C frequency of light (Ï)
D υ-υ0

The correct answer is:
intensity of light

Solution:
The number of photoelectrons decide the photocurrent. Assuming that the number of electrons emitted depends on the number of photons incident, the number of photoelectrons depend on the intensity of light.

Topic: Physics, Dual Nature of Matter, NEET
The number of photons falling per second on a completely darkened plate to produce a force of 6.62Ã10-5 N is n. If the wavelength of the light falling is 5Ã10-7 m, then n=â¦Ã1022.h=6.62Ã10-34 J-s

Options:
A 1
B 5
C 0.2
D 3.3

The correct answer is:
5

Solution:
Energy carried by n photons per second
P=n.hcÎ»
As photons get absorbed by dark plate, force experienced by the plate
F= 1 C .ân he Î»
Or FÃc=n.hcÎ» as power P=forceÃspeed
=FÃc
Or n=FÎ»h=6.62Ã10-5Ã5Ã10-76.62Ã10-34=5Ã1022

Topic: Physics, Dual Nature of Matter, NEET
The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of 3.3×10-3 W will be :h=6.6×10-34 J s

Options:
A 1018
B 1017
C 1016
D 1015

The correct answer is:
1016

Solution:
Energy of each photon, E=hcλ

⇒E=6.6×10-34×3×108600×10-9

⇒E=3.3×10-19 J

Number of photons emitted per second, N=PE

⇒N=3.3×10-33.3×10-19

⇒N=1016

Topic: Physics, Dual Nature of Matter, NEET, NEET 2021
The number of possible enantiomer pairs that can be produced during monochlorination of 2- methylbutane is

Options:
A 2
B 3
C 4
D 1

The correct answer is:
2

Solution:
No. of possible enantiomers

Topic: Chemistry, General Organic Chemistry, NEET
The number of possible optical isomers for the complexes MA2B2 with sp3 and dsp2 hybridized metal atom, respectively, is
Note: A and B are unidentate neutral and unidentate monoanionic ligands, respectively.

Options:
A 2 and 2
B 0 and 0
C 0 and 2
D 0 and 1

The correct answer is:
0 and 0

Solution:
As in MA2B2 tetrahedral structure which is sp3 hybridised, the central metal is not chiral hence it does not show optical isomers.
In the case of square planar that is dsp2 hybridised, two geometrical isomers will form but not optical isomers.

Topic: Chemistry, General Organic Chemistry, NEET
The number of possible organobromine compounds which can be obtained in the allylic bromination of 1-butene with N-bromosuccinimide is

Options:
A 1
B 2
C 3
D 4

The correct answer is:
4

Solution:
NBS (N-Bromosuccinimide) does allylic bromination through free radical substitution.
So total 4 isomers (2 geometrical and 2 optical) are possible.

Topic: Chemistry, General Organic Chemistry, NEET
The number of possible structural and configurational isomers of a bromo compound, formed by the addition of 1 mole of HBr to 2-pentyne respectively, are â

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

The correct answer is:
2 and 4

Solution:
If the two atoms or groups attached to each carbon atom are different, they can be represented by YXC = CXY like structure.
It can be represented in space in the following two ways.
(a) in which two identical atoms or groups lie on the same side of the double bond is called cis-isomer,
(b) in which identical atoms or groups lie on the opposite sides of the double bond is called trans-isomer.
They are known as Geometrical isomers.
C H 3 âCâ¡CâC H 2 C H 3 +HBrâ
Therefore, two structural and four configurational isomers.

Topic: Chemistry, Hydrocarbons, NEET