datavorous/entrance-exam-dataset huggingface dataset:
Mitochondria and chloroplast are:
(i) Semi - autonomous organelles
(ii) Formed by the division of pre-existing organelles and they contain DNA but lack protein synthesizing machinery
Which one of the following option is correct?

Options:
A Both (i) and (ii) are correct
B (ii) is true but (i) is false
C (i) is true but (ii) is false
D Both (i) and (ii) are false

The correct answer is:
(i) is true but (ii) is false

Solution:
Mitochondria and chloroplast are semi-autonomous organelles and they have their own ribosomes with the help of which they can synthesize protein.

Topic: Biology, Cell - The Unit of Life, NEET, NEET 2016 (Phase 1)
Mitosis is also known as ____ division.

Options:
A Reductional
B Rare
C Equational
D Common

The correct answer is:
Equational

Solution:
Mitosis is also known as equational division

Topic: Biology, Cell Cycle and Cell Division, NEET
Mitosis is characterised by

Options:
A Reduction division
B Equal division
C Both reduction and equal division
D Pairing of homologous chromosomes

The correct answer is:
Equal division

Solution:
Mitosis is the most dramatic period of the cell cycle, involving a major reorganisation of virtually all components of the cell. Since the number of chromosomes in the parent and progeny cells is the same, it is also called as equational division.

Topic: Biology, Cell Cycle and Cell Division, NEET
Mitosis is important in the life of an organism because:

Options:
A It produces diploid daughter cells
B It produces haploid daughter cells
C It produces multicellular organisms
D It produces both diploid daughter cells and multicellular organisms

The correct answer is:
It produces both diploid daughter cells and multicellular organisms

Solution:
Mitosis usually results in the production of diploid daughter cells with identical genetic complement. The growth of multicellular organisms is due to mitosis.

Topic: Biology, Cell Cycle and Cell Division, NEET
Mitosis occurs in

Options:
A Haploid individuals
B Diploid individuals
C Both haploid individuals and diploid individuals
D In bacteria only

The correct answer is:
Both haploid individuals and diploid individuals

Solution:
Somatic cells of a multicellular organism arise from a single cell by mitotic divisions. Body growth of a multicellular organism and replacement of its lost cells is accomplished through mitosis.
Animals undergo "open" mitosis, where the nuclear envelope breaks down before the chromosomes separate, while fungi undergo "closed" mitosis, where chromosomes divide within an intact cell nucleus.

Topic: Biology, Cell Cycle and Cell Division, NEET
Mixture containing aqueous Li+, Na+, K+ ions are electrolysed. cations are discharged at cathode in the order : (easiest at the end)

M + aq + e - ⟶ M

Options:
A Li + , Na + , K +
B K + , Na + , Li +
C Li + , K + , Na +
D Na + , K + , Li +

The correct answer is:
Na + , K + , Li +

Solution:
E red o	Metal

-3.05V	Li

-2.71V	Na

-2.93V	K

Higher the value of E red o more preferably the ions is reduced at cathode that is Na+ > K+ > Li+

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Mixture of 1 g each of Na2CO3 and NaHCO3 is reacted with 0.1 N HCl. The quantity of 0.1 M HCl required to react completely with the above mixture is

Options:
A 15.78 mL
B 157.8 mL
C 198.4 mL
D 308 mL

The correct answer is:
308 mL

Solution:
Na 2 CO 3 + 2 HCl â 2 NaCl + H 2 O + CO 2 1 mol 2 mol
Na 2 CO 3 = 1 g= 1 106 mol.N a 2 C o 3 ≡ 2 106 mol.HCl
NaHCO 3 + HCl â NaCl + H 2 O + CO 2
NaHCO 3 = 1 g = 1 8 4 mol â¡ 1 8 4 mol HCl
Total HCl required = 1 5 3 + 1 8 4 mol HCl
Let volume of 0.1 N HCl = V mL
then, Moles = 0.1 Ã V 1 0 0 0 = V 1 0 0 0 0
â´ V 1 0 0 00 = 1 5 3 + 1 8 4
= 0.0308 mol
V = 0.0308 Ã 1 0 0 0 0
= 308 mL

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Mixture of chloroxylenol and terpineol acts as

Options:
A Antiseptic
B Antipyretic
C Antibiotic
D Analgesic

The correct answer is:
Antiseptic

Solution:
Mixture of Chloroxylenol and terpineol acts as Antiseptic. These are components of Dettol.

Topic: Chemistry, Chemistry in Everyday Life, NEET
Mixture of volatile components A and B has total vapour pressure (in torr)
P=254-119XA
where, XA is mole fraction of A in mixture. Hence, PAo and PBo are (in torr)

Options:
A 254, 119
B 119, 254
C 135, 254
D 154, 119

The correct answer is:
135, 254

Solution:
When XA=1,
P=PAo
So PAo=254-119=135torr
When XA=0,
P=PBo
So PBo=254 torr.

Topic: Chemistry, Solutions, NEET
$\left[\mathrm{Mn}_2(\mathrm{CO})_{10}\right]$ and $\left[\mathrm{Co}_2(\mathrm{CO})_8\right]$ structures have
A. Metal-Metal linkage
B. Terminal CO groups
C. Bridging CO groups
D. Metal in zero oxidation state
Choose the correct answer from the options given below

Options:
A Only A, B, C
B Only B, C, D
C Only A, C, D
D Only A, B, D

The correct answer is:
Only A, B, D

Solution:
A. Metal-Metal linkage present.
B. Terminal CO groups are present
C. In $\left[\mathrm{Mn}_2(\mathrm{CO})_{10}\right]$ bridging CO groups are not present.
D. Metal is in zero oxidation state.

Topic: Chemistry, Coordination Compounds, NEET, NEET 2024 (Re-NEET)
Mobility of free electrons in a conductor is

Options:
A Directly proportional to electron density
B Directly proportional to relaxation time
C Inversely proportional to electron density
D Inversely proportional to relaxation time

The correct answer is:
Directly proportional to relaxation time

Solution:
Electron mobility ∝ Drift velocity.
Mobility of free electron in a conductor is directly proportional to relaxation time.
u∝τ

Topic: Physics, Current Electricity, NEET
Mode of nutrition found in fungi

Options:
A Photosynthetic
B Chemosynthetic
C Saprophytic/parasitic
D Holozoic

The correct answer is:
Saprophytic/parasitic

Solution:
Fungi usually have saprophytic mode of nutrition, i.e. they secrete digestive juices to digest the organic matter and then absorb the digested form

Topic: Biology, Biological Classification, NEET
Modern detergents contain enzyme preparations of

Options:
A acidophiles
B alkaliphiles
C thermoacidophiles
D thermophiles

The correct answer is:
alkaliphiles

Solution:
Detergents represent the largest industrial application of enzymes amounting to $25-30 \%$ of total sales of enzyme. The enzymes used in detergents must be cost effective, safe to use, and be able to perform the task in the presence of anionic and non-ionic detergents, soaps, oxidants etc, at $\mathrm{pH}$ between $8-10.5 \%$. The chief enzymes used are proteases, $\alpha$-amylase and sometimes cellulase.

Topic: Biology, Biotechnology - Principles and Processes, NEET, NEET 2008 (Screening)
Modern Homo sapiens arose during ice age between

Options:
A 15,000–5,000 years ago
B 5 million years ago
C 15 million years ago
D 75,000–10,000 years ago

The correct answer is:
75,000–10,000 years ago

Solution:
Modern Homo sapiens arose in Africa during ice age 75,000â10,000 years ago, moved to different continents and developed into various races.

Topic: Biology, Evolution, NEET
Modification in the form of leaf spines and stem thorns is observed in

Options:
A watermelon and Australian babool
B pumpkin and cacti
C cacti and Citrus
D Citrus and cacti

The correct answer is:
cacti and Citrus

Solution:
Leaf spines are the modification of leaves. They reduce the loss of water and protect the plant. Stem thorns are the modification of stems. They are woody, strong and help in protection and climbing for woody climber plants.

Topic: Biology, Morphology of Flowering Plants, NEET
Modified polysaccharides acting as a ground substance is found in:

Options:
A Epithelial tissue
B Connective tissue
C Muscular tissue
D Neural tissue

The correct answer is:
Connective tissue

Solution:
In all connective tissues except blood, the cells secrete fibres of structural proteins called collagen or elastin. The fibres provide strength, elasticity and flexibility to the tissue. These cells also secrete modified polysaccharides, which accumulate between cells and fibres and act as matrix (ground substance).

Topic: Biology, Structural Organisation in Animals, NEET
MOET is method of:

Options:
A fish cultivation
B cloning in sheep
C hybridization in cattle
D birth control in humans

The correct answer is:
hybridization in cattle

Solution:
MOET (multiple ovulation embryo transfer) is a method of insemination where embryos (fertilised eggs) are transferred into the cow's uterus.

Topic: Biology, Strategies for Enhancement in Food Production, NEET
MOET means

Options:
A Multiple Ovulation Embryo Transfer Technology
B Mature Ovulation Embryo Transfer Technology
C Multiple Ovulation Embryo Transplant Technology
D Multiple Ovulation Energy Transfer Technology

The correct answer is:
Multiple Ovulation Embryo Transfer Technology

Solution:
An important aspect of animal husbandry is animal breeding which aims at improving the quality and yield of the produce. Breeding between animals of same breed is call inbreeding where as between animals of different breeds is called out breeding. The success rate of cross between male and female is improved using the technique of MOET (Multiple Ovulation Embryo Transfer Technology). Hormones having FSH like action are administered to the cow to induce follicular maturation and super ovulation i.e. release of multiple eggs in a single cycle. The animal is then either mated or artificially inseminated and the fertilized eggs are retrieved at the 8-32 celled stages and transferred into the surrogate mothers.

Topic: Biology, Strategies for Enhancement in Food Production, NEET
MOET (Multiple Ovulation Embryo Transfer) is a method of

Options:
A fish cultivation
B hybridisation of cattle
C birth control
D cloning of sheep

The correct answer is:
hybridisation of cattle

Solution:
MOET (Multiple Ovulation Embryo Transfer) is the method to improve the production of hybrids. In this technique, cattle are injected with hormones similar to FSH to enhance follicular development and this will result in superovulation. Due to this technique, more than one egg is ovulated. This animal is then mated with superior bull or sperms from such superior variety are inseminated into the female cattle's body. After fertilization, the eggs are recovered by non-surgical means and transferred to surrogate mothers. This is done so that the female cattle are again available for super ovulation. Thus this technique has been successfully used for the hybridization of cattle.

Topic: Biology, Strategies for Enhancement in Food Production, NEET
Moist cuticle is the respiratory organ in

Options:
A Insects
B Earthworms
C Aquatic arthropods and molluscs
D Amphibians like frogs

The correct answer is:
Earthworms

Solution:
Animals	Respiration
Lower invertebrates like sponges, coelenterates, flatworms	Entire / general body surface
Earthworms	Moist cuticle
Insects	Network of tubes (tracheal tubes)
Aquatic arthropods and molluscs	Gills (special vascularised structures)
Fishes	Gills
Amphibians like frogs	Lungs and moist skin
Reptiles, birds and mammals	Lungs

Topic: Biology, Breathing and Exchange of Gases, NEET
Molar conductance of an electrolyte increases with dilution according to the equation:
$\Lambda_{\mathrm{m}}=\Lambda_{\mathrm{m}}^{\circ}-\mathrm{A} \sqrt{\mathrm{c}}$
Which of the following statements are true?
(A) This equation applies to both strong and weak electrolytes.
(B) Value of the constant A depends upon the nature of the solvent.
(C) Value of constant $\mathrm{A}$ is same for both $\mathrm{BaCl}_2$ and $\mathrm{MgSO}_4$.
(D) Value of constant $A$ is same for both $\mathrm{BaCl}_2$ and $\mathrm{Mg}(\mathrm{OH})_2$.
Choose the most appropriate answer from the options given below.

Options:
A (B) and (C) only
B (B) and (D) only
C (A) and (B) only
D $(A),(B)$ and $(C)$ only

The correct answer is:
(B) and (D) only

Solution:
$\Lambda_m=\Lambda_m^{\circ}-A \sqrt{c}$
- For strong electrolytes, $\Lambda_{\mathrm{m}}$ increases slowly with dilution.
- The value of ' $A$ ' depends on the type of electrolyte.
- All electrolytes of particular type have the same value for 'A'
e.g. $\mathrm{BaCl}_2$ and $\mathrm{Mg}(\mathrm{OH})_2 \rightarrow 2-1$ electrolytes

Topic: Chemistry, Electrochemistry, NEET, NEET 2023 (Manipur)
Molar conductivity of a solution of an electrolyte AB3 is 150 Scm2mol-1 . If it ionizes as AB 3 → A 3+ +3 B − , its equivalent conductivity will be

Options:
A 150(in Scm2eq-1)
B 75(in Scm2eq-1)
C 50(in Scm2eq-1)
D 80(in Scm2eq-1 )

The correct answer is:
50(in Scm2eq-1)

Solution:
∧eq=1n+×Z+∧m
Where, ∧m= molar conductance
n+= number of cations
Z+= charge of cation
∧eq=11×3×150=50

Topic: Chemistry, Electrochemistry, NEET
Molar heat capacity at constant P for a substance is equal to

Options:
A (∂U/∂T)v
B (∂H/∂T)v
C (∂U/∂T)p
D (∂H/∂T)p

The correct answer is:
(∂H/∂T)p

Solution:
Cp=QpΔT=ΔHΔT
or ∂H∂Tp .

Topic: Chemistry, Thermodynamics (C), NEET
Molarity, normality and molality of the solution containing 22% of Al2(SO4)3{d=1.253 g/mL} by weight are

Options:
A 0.825 M,48.3 N,0.825 m
B 0.805 M,4.83 N,0.825 m
C 4.83 M,4.83 N,4.83 m
D None

The correct answer is:
0.805 M,4.83 N,0.825 m

Solution:
Molarity =%×10×dGMM=22×10×1.253342=0.805 M
Normality =%×10×dGEM =22×10×1.253342/6=4.83 N
Molality =22×1000342(100-22)=0.825 m

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Mole fraction of the solute in a 1.00 molal aqueous solution is

Options:
A 0.0177
B 0.0344
C 1.7700
D 0.1770

The correct answer is:
0.0177

Solution:
1.00 molal aqueous solution $=1.0$ mole in $100 \mathrm{~g}$ water $n_{\text {solute }}=1 ; W_{\text {solvent }}=1000 \mathrm{~g}$.
$$
\begin{aligned}
& n_{\text {solvent }}=\frac{1000}{18}=55.56 \\
& X_{\text {solute }}=\frac{1}{1+55.56}=0.0177
\end{aligned}
$$

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET, NEET 2011 (Screening)
Mole ratio of Fe in FeO,Fe2O3 and Fe3O4 samples of equal weights is

Options:
A 1 : 2 : 3
B 0.9 : 1 : 0.93
C 1 : 0.9 : 0.93
D 3 : 2 : 1

The correct answer is:
1 : 0.9 : 0.93

Solution:
As mole, n=wmolecular&nbspwt.
Moles of FeO : Fe2O3:Fe3O4
w72:w160:w232
moles of Fe=w72:2×w160:3&nbspw232
i.e., 1 : 0.9 : 0.93.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Molecular basis of organ differentiation depends on the modulation in transcription by:

Options:
A ribosome
B transcription factor
C anticodon
D RNA polymerase.

The correct answer is:
transcription factor

Solution:
The process of formation of protein sequence from DNA strand is called transcription which requires RNA polymerase chain. RNA polymerase chains are of three-types in eukaryotes:
(i) RNA polymerase-I
(ii) RNA polymerase II
(iii) RNA polymerase-III

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2007
Molecular hydrides are classified as electron deficient, electron precise and electron rich compounds. Explain each type with two examples.

Options:
A (i) Electron Deficient Boranes (ii) Electron Precise Methane (iii) Electron Rich Ammonia
B (i) Electron Deficient Water (ii) Electron Precise Ammonia (iii) Electron Rich Methane
C (i) Electron Deficient Methane (ii) Electron Precise Ammonia (iii) Electron Rich Boranes
D (i) Electron Deficient Boranes (ii) Electron Precise Ammonia (iii) Electron Rich Methane

The correct answer is:
(i) Electron Deficient Boranes (ii) Electron Precise Methane (iii) Electron Rich Ammonia

Solution:
Correct Option is : (A)
(i) Electron Deficient Boranes (ii) Electron Precise Methane (iii) Electron Rich Ammonia

Topic: Chemistry, Hydrogen, NEET
Molecular sizes of ICl and Br2 are nearly same but boiling point of ICl is about 40oC higher than Br2 . Because.

Options:
A I-Cl is weaker than Br - Br bond
B Ionisation energy of Br atom is less than I atom
C ICl is a polar where as Br2 atom is a non - polar molecule
D ICl is non - polar where as Br2 is polar

The correct answer is:
ICl is a polar where as Br2 atom is a non - polar molecule

Solution:
Br - Br is a non - polar whereas I - Cl is a polar bond because of electronegativity difference between I and Cl. Polarity in the bond increases the bond - energy and thus the boiling point.
B r 2 Î¼=0; ICl Î¼â 0
Strong intermolecular force of attractions amongst ICl molecules

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Molecular weight of an organic acid is given by:

Options:
A Equivalent weight Ã basicity
B EquivalentÂ WeightBasicity
C BasicityEquivalentÂ Weight
D EquivalentÂ weightÂ ÃValency

The correct answer is:
Equivalent weight Ã basicity

Solution:
Mol.mass of an acid=Equivalent wt.Ã basicity

Topic: Chemistry, General Organic Chemistry, NEET
Molecular weight of oxalic acid is 126. The weight of oxalic acid required to neutralise 100 cc of normal solution of NaOH is

Options:
A 6.3 gm
B 126 gm
C 530 gm
D 63 gm

The correct answer is:
6.3 gm

Solution:
no. of equivalent of acid = no of equivalent of Base
( Weight Molecularâweight Ã'n'factor ) Base =ââ ( NÃ V liter ) Acid
â´ n factor of NaOH = 1
â´ n factor of Oxalic acid = 1
1 = x Ã 100063 Ã 100 x= 6.3 gms

Topic: Chemistry, Redox Reactions, NEET
Molisch's test given by

Options:
A Carbohydrates
B Lipids
C Amino acid
D Proteins

The correct answer is:
Carbohydrates

Solution:
Molisch's testis used for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with two molecules of a phenol (usually α -naphthol, though other phenols such as resorcinol and thymol also give colored products), resulting in a violet ring.

Topic: Chemistry, Biomolecules, NEET
Molish test is given by :

Options:
A All carbohydratres
B Sucrose only
C Fructose only
D Glucose only

The correct answer is:
All carbohydratres

Solution:
Molisch test is a test for carbohydrate or compounds which can be dehydrated to furfural or furfural derivatives in the presence of the concentrated sulphuric acid (H2SO4).
All carbohydrates give Molisch test.

Topic: Chemistry, Biomolecules, NEET
Moll's Half leaf experiment proves that

Options:
A light is essential for photosynthesis
B CO2 is essential for photosynthesis
C O2 is released during photosynthesis
D chlorophyll is essential for photosynthesis

The correct answer is:
CO2 is essential for photosynthesis

Solution:
In Moll's half leaf experiment a part of the leaf was inserted in a flask using a split cork. The flask contains KOH which absorbs the CO2 present in the flask. Thus the part of leaf inside the flask cannot carry out synthesis of starch, indicating the CO2 is necessary for photosynthesis.

Topic: Biology, Photosynthesis in Higher Plants, NEET
Molten sodium chloride conducts electricity due to the presence of

Options:
A Free electrons
B Free ions
C Free molecules
D Atoms of sodium and chlorine

The correct answer is:
Free ions

Solution:
Molten sodium chloride conducts electricity due to the presence of Free ions as in molten sodium chloride ions become free to move and hence conduct electricity.

Topic: Chemistry, s Block Elements, NEET
Molybdenum is absorbed as -

Options:
A MoO4³⁺
B MoO2²⁺
C Mo(SO4)2
D MoO2³⁺

The correct answer is:
MoO2²⁺

Solution:
Plants obtain Molybdenum in the form of molybdate ions MoO2²⁺

Topic: Biology, Mineral Nutrition, NEET
Moment of inertia of a disc about diameter is I. Find the moment of inertia of disc about an axis perpendicular to its plane and passing through its rim.

Options:
A 6I
B 4I
C 2I
D 8I

The correct answer is:
6I

Solution:
Moment of inertia of a disc about a diameter is
14 MR2=I (given)
â´ MR2=4I
Now, required moment of inertia =32MR2
=324I=6I

Topic: Physics, Rotational Motion, NEET
Moment of inertia of a uniform quarter disc of radius R and mass M about an axis through its centre of mass and perpendicular to its plane is

Options:
A MR22-M4R3Ï2
B MR22-M24R3Ï2
C MR22-M4R2π2
D MR22+M24R3π2932π

The correct answer is:
MR22-M24R3π2

Solution:
Moment of Inertia of the object about O is MR22
By parallel axis theorem
MR22=Icm+M4R3Ï22
Icm=MR22-M24R3Ï2

Topic: Physics, Rotational Motion, NEET
Monascus purpureus is a yeast used commercially in the production of

Options:
A ethanol
B streptokinase for removing clots from the blood vessels
C citric acid
D blood cholesterol lowering statins

The correct answer is:
blood cholesterol lowering statins

Solution:
Monascus purpureus is a yeast used in the production of statins which are blood cholesterol lowering agents.

Topic: Biology, Microbes in Human Welfare, NEET, NEET 2012 (Screening)
Monascus purpureus is a yeast used commercially in the production of:

Options:
A Ethanol
B Streptokinase for removing clots from the blood vessels
C Citric acid
D Blood cholesterol lowering statins

The correct answer is:
Blood cholesterol lowering statins

Solution:
Monascus purpureus is used for commercial production of Statin which is used as a blood cholesterol-lowering agent by binding competitively to the enzyme responsible for the synthesis of cholesterol.

Topic: Biology, Microbes in Human Welfare, NEET
Monascus purpureus is the yeast used commercially in the production of

Options:
A streptokinase for removing clots from the blood vessels.
B citric acid.
C blood cholesterol-lowering statins.
D ethanol.

The correct answer is:
blood cholesterol-lowering statins.

Solution:
Red yeast rice (Monascus purpureus) is rice fermented with red yeast. This red yeast rice is used as a supplement for lowering the blood cholesterol levels. Streptokinase (fibrinolytic agent) is obtained from strain of Streptococcus haemolyticus. Citric acid and gluconic acid are produced by Aspergillus niger. Ethanol is formed by Saccharomyces cerevisiae.

Topic: Biology, Microbes in Human Welfare, NEET
Monascus purpureus is used commercially in the production of

Options:
A Citric acid
B Streptokinase
C Statins
D Cyclosporin A

The correct answer is:
Statins

Solution:
Monascus purpureus is the yeast used commercially in the production of blood-cholesterol-lowering statins. It is a species of mold that is purplish-red in color.

Topic: Biology, Microbes in Human Welfare, NEET
Monerans with both carbon and nitrogen reducing enzymes are

Options:
A	All photosynthetic bacteria
B Heterocystous BGA and some photosynthetic bacteria
C Heterocystous BGA but no eubacteria
D All photoautotrophic bacteria and some BGA

The correct answer is:
Heterocystous BGA and some photosynthetic bacteria

Solution:
Cyanobacteria or blue-green algae and photosynthetic bacteria (contain chlorophyll, are placed under kingdom Monera. Nitrogen fixing cyanobacteria need only nitrogen and carbon dioxide to live. The presenece of heterocysts, which contain the enzyme nitrogenase, vital for nitrogen fixation.

Topic: Biology, Biological Classification, NEET
Monochromatic light is refracted from air into a glass of refractive index Î¼. The ratio of the wavelength of the incident and refracted waves is

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

The correct answer is:
μ : 1

Solution:
Since the frequency μ of the light does not change as light travels from air into glass,
we have,
υ a = μ λ a and υ g = μ λ g
Therefore λ a λ g = υ a υ g = μ

Topic: Physics, Ray Optics, NEET
Monochromatic light of frequency $6.0 \times$ $10^{14} \mathrm{~Hz}$ is produced by a laser. The power emitted is $2 \times 10^{-3} \mathrm{~W}$. The number of photons emitted, on the average, by the source per second is:

Options:
A $5 \times 10^{16}$
B $5 \times 10^{17}$
C $5 \times 10^{14}$
D $5 \times 10^{15}$

The correct answer is:
$5 \times 10^{15}$

Solution:
$\eta=\frac{p}{m v}=\frac{2 \times 10^{-3}}{6.62 \times 10^{-34} \times 6 \times 10^{14}}$ $=5 \times 10^{15}$

Topic: Physics, Dual Nature of Matter, NEET, NEET 2007