datavorous/entrance-exam-dataset huggingface dataset:
The volume of blood pumped out by each ventricle per cardiac cycle is called ____X_____ which is about _____Y_____ . Select the correct option for X and Y .

Options:
A X- Stroke Volume; Y-70 ml
B X- Cardiac output; Y-50 ml
C X- Isovolumetric Systole; Y-50Â ml
D X- Isovolumetric Diastole; Y-30Â ml

The correct answer is:
X- Stroke Volume; Y-70 ml

Solution:
The volume of blood pumped from the heart (left ventricle) into the systemic aorta in one minute is called the cardiac output. It is also called minute volume. It is calculated as the product of stroke volume (amount of blood pumped by left ventricle each time it contracts) and rate of heartbeat, i.e.,
Cardiac output = Stroke volume x Rate of heart beat = 70 ml x 75 times/minute = 5250 ml/minute or 5.25 litres/minute.

Topic: Biology, Body Fluids and Circulation, NEET
The volume of brick is 2.197 L . The submerged brick is balanced by a 2.54 kg mass on the beam scale. The weight of the brick is

Options:
A 46 N
B 50 N
C 56 N
D 72 N

The correct answer is:
46 N

Solution:
T+FB-W=0
W=T+FB=2.54×9.8+103×2.197×10-3×10
W=46.43 N

Topic: Physics, Mechanical Properties of Fluids, NEET
The volume percentage of Cl2 at equilibrium in the dissociation of PCl5 under a total pressure of 1.5atm is (Kp=0.202) ,

Options:
A 74.5
B 36.5
C 63.5
D 26.6

The correct answer is:
26.6

Solution:
PCl5âPCl3+Cl2
1-x x x
Total moles =1-x+x+x=1+x
k p = P PCl 3 â PCl 2 P PCl 5 = x 1+x P 1âx 1+x P x 1+x P
kP=x2P1-x2 1-x2=1
kP=x2P
x=kpP=0.2021.5=0.134=0.366
Mole â volume at constant P&T
Volume percentage =mole of Cl2totalmolesÃ100
=0.3661.366Ã100=26.86%

Topic: Chemistry, Chemical Equilibrium, NEET
The volume ratio of 6N and 2N HCl required to prepare 100 mL of 5N HCl is

Options:
A 3 : 1
B 1 : 3
C 4 : 1
D 1 : 4

The correct answer is:
3 : 1

Solution:
Let a mL of 6N and 100−a  mL of 2N are mixed
So 6a+2(100-a)=100Ã5
aâ=â75âmL, 100â1 â=â25âmL

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
The Volume V of a monoatomic gas varies with its temperature T, as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a change from state A to state B, is

Options:
A 13
B 23
C 25
D 27

The correct answer is:
25

Solution:
VâT
â Isobaric process
W=PâV=nRâT
âQ=nCPâT
For mono atomic gas f = 3
CP=f2R+R=52R
So WâQ=nRâTnCPâT=25

Topic: Physics, Thermodynamics, NEET, NEET 2018
The walking fern is named so because

Options:
A Its spores are able to walk
B It is dispersed through the agency of walking animals
C It propagates vegetatively by its leaf tips
D It known how to walk by itself

The correct answer is:
It propagates vegetatively by its leaf tips

Solution:
Adiantum caudatum is commonly called walking fern because its leaf tips when coming in contact with soil, form new plants as adventitious buds develop at leaf tips. This helps in the spread of fern over a large soil surface and thus, the name walking fern is derived.

Topic: Biology, Plant Kingdom, NEET
The wall of bacteria consists of

Options:
A N-acetylglucosamine
B N-acetyl muramic acid
C Both (a) and (b)
D Cellulose

The correct answer is:
Both (a) and (b)

Solution:
The bacterial cell wall contains peptidoglycan or mucopeptide or murein with diaminopimelic acid, lipid and protein. Chemically, peptidoglycan is composed of N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM).

Topic: Biology, Biological Classification, NEET
The waste products produced in man are

Options:
A Carbon dioxide
B Urea and salts
C Excess of water
D All of these

The correct answer is:
All of these

Solution:
Animals accumulate ammonia, urea, uric acid, carbon dioxide, water and ions like Na+, K+, Cl–, phosphate, sulphate, etc., either by metabolic activities or by other means like excess ingestion. These substances have to be removed totally or partially. Excretion is the elimination of metabolic wastes from the body. Carbon dioxide is removed through the respiration process and other substances like mineral, salts, urea, water, pigments etc., are removed by excretion.

Topic: Biology, Excretory Products and their Elimination, NEET
The water channels are made up of how many different types of aquaporins?

Options:
A 4
B 8
C 5
D 7

The correct answer is:
8

Solution:
The transport protein then rotates and releases the molecule inside the cell, e.g., water channels – made up of eight different types of aquaporins.

Topic: Biology, Transport in Plants, NEET
The water gas (CO+H2) at 673 K and 300 atmosphere in presence of the catalyst Cr2O3/ZnO is used for the manufacture of

Options:
A CH3OH
B HCOOH
C HCHO
D CH3COOH

The correct answer is:
CH3OH

Solution:
(CO+ H 2 ) →   Cr 2 O 3 /ZnO  CH 3 OH

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
The water potential and osmotic potential of pure water is

Options:
A Zero and zero
B 100 and 100
C Zero and 100
D 100 and zero

The correct answer is:
Zero and zero

Solution:
Osmotic potential is the potential of a solution to cause water movement into it across a semipermeable membrane. Water potential is the tendency of water to leave a system, which is zero for pure water.

Topic: Biology, Transport in Plants, NEET
The water potential of pure water is

Options:
A Zero
B Less than zero
C More than zero but less than one
D More than one

The correct answer is:
Zero

Solution:
Water potential is the chemical potential of water. When the solute is added to the pure water, this chemical potential drops and the water potential also falls. The water potential of pure water in an open container is zero because there is no solute and the pressure in the container is zero. Water potential cannot be in positive, and when solute is added, it falls from less negative to more negative.

Topic: Biology, Transport in Plants, NEET, NEET 2017
The wave nature of electrons was experimentally verified by,

Options:
A de Broglie
B Hertz
C Einstein
D Davisson and Germer

The correct answer is:
Davisson and Germer

Solution:
In the Davison Germer experiment, the light scattered by the surface of a crystal showed a diffraction pattern. And hence, it experimentally provided evidence for the wave nature of photons.

Topic: Physics, Electromagnetic Waves, NEET, NEET 2020 (Phase 2)
The wavelength corresponding to the maximum energy, released during an atomic explosion was 2.93×10-10 m. Given that the wien's constant is b=2.93×10-3 mK, then the maximum temperature attained must be of the order of

Options:
A 10-7Â K
B 107 K
C 10-3 K
D 5.86Ã107 K

The correct answer is:
107 K

Solution:
Wien's displacement law is given by
Î»mT=constant (say b)
Given, b= Wien's constant =2.93Ã10-3 m-K
Î»m=2.93Ã10-10m
Substituting the values, we obtain
T=bÎ»m
=2.93Ã10-32.93Ã10-10=107 K

Topic: Physics, Thermal Properties of Matter, NEET
The wavelength $\lambda_e$ of an electron and $\lambda_p$ of a photon of same energy $E$ are related by

Options:
A $\lambda_p \propto \lambda_e^2$
B $\lambda_p \propto \lambda_e$
C $\lambda_p \propto \sqrt{\lambda_e}$
D $\lambda_\rho \propto \frac{1}{\sqrt{\lambda_e}}$

The correct answer is:
$\lambda_p \propto \lambda_e^2$

Solution:
Wavelength of electron,
$$
\begin{aligned}
& \lambda_e=\frac{h}{\sqrt{2 m E}} \\
& \text { and proton } \lambda_p=\frac{h c}{E} \\
& \Rightarrow \quad \lambda_e^2=\frac{h^2}{2 m E} \text { or } E=\frac{h c}{\lambda_p} \\
& \therefore \quad \lambda_e^2=\frac{h^2}{2 m \cdot \frac{h c}{\lambda_p}} \Rightarrow \lambda_e^2=\frac{h^2}{2 m h C} \lambda_p \\
& \Rightarrow \quad \lambda_e^2 \propto \lambda_p
\end{aligned}
$$

Topic: Physics, Dual Nature of Matter, NEET, NEET 2013 (All India)
The wavelength Î»m=5.5Ã10-7 m when the temperature of the sun is 5500 K. If the furnace has a wavelength Î»m equal to 11Ã10-7 m, then the temperature of the furnace is

Options:
A 5000 K

B 1750 K

C 3750 K

D 2750 K

The correct answer is:
2750 K

Solution:
According to Wien's displacement law,
λmT=b or λm ∝1T
Where b is Wien's constant whose value is 29×10-3 m K
λmSλmF= TFTS
Or TF=TS×λmSλmF = 5500 K × (5.5×10-7 m)(11×10-7 m)
= 2750 K

Topic: Physics, Thermal Properties of Matter, NEET
The wavelength of a 1 keV photon is 1.24×10-9m. What is the frequency of 1 MeV photon?

Options:
A 2.5×1015Hz
B 2.5×1020Hz
C 1.24×1015Hz
D 1.24×1020Hz

The correct answer is:
2.5×1020Hz

Solution:
hcλ=1000 eV

hv=106 eV

⇒λνc=1000 eV
⇒v=3×108×10001.2×10-9=2.5×1020 Hz

Topic: Physics, Dual Nature of Matter, NEET
The wavelength of de-Broglie wave is 2 Î¼m then its momentum is
(h=6.63Ã 10-34 J s)

Options:
A 3.315Ã10-28 kg m s-1
B 1.66Ã10-28 kg m s-1
C 4.97Ã10-28 kg m s-1
D 9.9Ã10-28 kg m s-1

The correct answer is:
3.315Ã10-28 kg m s-1

Solution:
According to de-Broglie hypothesis
Î»=hp
Where, h is Planck's constant.
â p=hÎ»
Given, h=6.63Ã10-34 J-s
Î»=2 Î¼m=2Ã10-6 m
â´ p=6.63Ã10-342Ã10-6
= 3.315Ã10-28 kg m s-1

Topic: Physics, Dual Nature of Matter, NEET
The wavelength of HÎ± line in the hydrogen spectrum is found to be 6563 â« in the laboratory. If the velocity of the milky way is 1.05Ã106 m s-1, then the wavelength of HÎ± line in the spectrum of milky way will be

Options:
A 6457Â â«
B 6586 â«
C 7123Â â«
D 7349Â â«

The correct answer is:
6586 â«

Solution:
As λ=∆λ×cv or ∆λ=λ×vc
∆λ=6563×1.05×1063×108Å=2297×10-2
=22.97 Å≈23 Å
∴ New wavelength is 6563+23 Å
=6586 Å

Topic: Physics, Wave Optics, NEET
The wavelength of light absorbed by $\mathrm{P}_r$ form of phytochrome:

Options:
A $680 \mathrm{~nm}$
B $720 \mathrm{~nm}$
C $620 \mathrm{~nm}$
D $640 \mathrm{~nm}$

The correct answer is:
$680 \mathrm{~nm}$

Solution:
Light acts as a signal to initiate and regulate photoperiodism and photomorphogenesis. There are two light-sensing systems involved in these responses, the blue light-sensitive system and the red light-sensitive or phytochrome system. The action spectrum of the light needed for \(\mathrm{P}_{\mathrm{r}}\) responses is at about 680 nm.
So, the correct answer is '680 nm'

Topic: Biology, Photosynthesis in Higher Plants, NEET, NEET 2007
The wavelength of light emitted from the second orbit to the first orbit in a hydrogen atom is

Options:
A 6563 A∘
B 4102 A∘
C 4861 A∘
D 1215 Aâ

The correct answer is:
1215 Aâ

Solution:
1λ=R112-122
⇒ 1λ=1.097 ×107×34
∴ λ =1.215 ×10-7 m = 1215 A∘

Topic: Physics, Atomic Physics, NEET
The wavelength of light from the spectral emission line of sodium is 589 nm. The kinetic energy at which a neutron would have the same de Broglie wavelength is

Options:
A 3.81 x 10-28 J
B 3.81 x 10-25 J
C 4.81 x 10-28 J
D 4.81 x 10-30 J

The correct answer is:
3.81 x 10-28 J

Solution:
Given, wavelength of light = 589 nm = 589 x 10-9 m
Mass of electron me = 9.1 x 10-31 kg
Mass of neutron mn = 1.67 x 10-27 kg
Planck's constant h = 6.62 x 10-34 J - s
Kinetic energy of neutron
KE n = h 2 2 λ 2 m n
= 6 . 6 3 × 1 0 - 3 4 2 2 × 5 8 9 × 1 0 - 9 2 × 1 . 6 6 × 1 0 - 2 7
= 3 . 8 1 × 1 0 - 2 8 J .

Topic: Physics, Atomic Physics, NEET
The wavelength of line emitted when an electron jumps from an outer orbit to inner orbit which possess an energy difference of 3 eV will be:

Options:
A 3660 Å
B 3620 Å
C 4140 â«
D 4560 Å

The correct answer is:
4140 â«

Solution:
Use E = hc/λ
Or E(ev) =  12420 λ(Å)
⇒λ(Å) =  12420 3  = 4140 Å

Topic: Chemistry, Structure of Atom, NEET
The wavelength of Lyman series of hydrogen atom appears in

Options:
A Ultraviolet region
B Infrared region
C Visible region
D Far infrared region

The correct answer is:
Ultraviolet region

Solution:
The wavelength of Lyman series of hydrogen atom appears in Ultraviolet region.

Topic: Physics, Atomic Physics, NEET, NEET 2023 (Manipur)
The wavelength of the de-Broglie wave associated with a thermal neutron of mass m at absolute temperature T is given by (Here, k is the Boltzmann constant)

Options:
A h2mkT
B hmkT
C h3kmT
D h2mkT

The correct answer is:
h3kmT

Solution:
KE of thermal neutron, 12mv2=32kT
or mv=3kmT; So, λ=hp=h3kmT

Topic: Physics, Dual Nature of Matter, NEET
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number $Z$ of hydrogen like ion is

Options:
A 4
B 1
C 2
D 3

The correct answer is:
2

Solution:
Lyman series for $\mathrm{H}$-ion
$$
\frac{h c}{\lambda}=R h c\left(\frac{1}{1^2}-\frac{1}{2^2}\right)
$$
And for H-like ion
$$
\begin{aligned}
\frac{h c}{\lambda} & =Z^2 R h c\left(\frac{1}{2^2}-\frac{1}{4^2}\right) \\
\therefore \quad\left(\frac{1}{1^2}-\frac{1}{2^2}\right) & =Z^2\left(\frac{1}{4}-\frac{1}{16}\right) \\
\left(1-\frac{1}{4}\right) & =Z^2\left(\frac{1}{4}-\frac{1}{16}\right) \\
Z & =2
\end{aligned}
$$

Topic: Physics, Atomic Physics, NEET, NEET 2011 (Screening)
The wavelength of the K α line for an element of atomic number 43 is λ . Then the wavelength of the Kα line for an element of atomic number 29 is

Options:
A 4329λ
B 4228λ
C 94λ
D 49λ

The correct answer is:
49λ

Solution:
ν∝(Z-1)2
or cλ∝(Z-1)2
For atomic number 43
1λ∝(43-1)2
For atomic number 29
1λ1∝(29-1)2
So λ1=(42)2(28)2×λ=94λ .

Topic: Chemistry, Structure of Atom, NEET
The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant =1.097×107 m-1 )

Options:
A 192 nm
B 4.6 nm
C 9.1×10-8 nm
D 91 nm

The correct answer is:
91 nm

Solution:
1Î»=vÂ¯H=RÂ¯H1n12-1n22
=1.097Ã107112-1â2
Î»=11.097Ã107 m=9.11Ã10-8 m
=91.1Ã10-9 m
=91.1 nm(As 1 nm=10-9 m)

Topic: Chemistry, Structure of Atom, NEET
The wavelength range of the visible spectrum extends from violet (400 nm) to red (750 nm). What is these wavelength range in terms of frequencies(Hz)? (1nm = 10–9m)

Options:
A 1.7 × 1014Hz to 5.0 × 1014Hz
B 6.0 × 1014Hz to 9.5 × 1014Hz
C 4.0 × 1014Hz to 7.5 × 1014Hz
D 4.0 × 1014Hz to 8.5 × 1014Hz

The correct answer is:
4.0 × 1014Hz to 7.5 × 1014Hz

Solution:
Correct Option is : (C)
4.0 × 1014Hz to 7.5 × 1014Hz

Topic: Chemistry, Structure of Atom, NEET
The wavelength will be minimum for which of the following electronic transition in an unielectron species?

Options:
A n = 6 to n = 4
B n = 4 to n = 2
C n = 3 to n = 1
D n = 2 to n = 1

The correct answer is:
n = 3 to n = 1

Solution:
E 3 − E 1  >  E 2 − E 1  >  E 4 − E 2  >  E 6 − E 4
ΔE =  E n 2 − E n 1 =13.6 ×  Z 2 1 n 1 2 − 1 n 2 2
ΔE = 1 n 1 2 − 1 n 2 2
Greater is the energy lesser is the wavelength.
Thus, λ for n3 to n1 will minimum.

Topic: Chemistry, Structure of Atom, NEET
The wavelengths involved in the spectrum of deuterium ( 1 2 D ) are slightly different from that of hydrogen spectrum, because-

Options:
A Sizes of the two nuclei are different
B Nuclear forces are different in the two cases
C Masses of the two nuclei are different
D Attraction between the electron and the nucleus is different in the two cases

The correct answer is:
Masses of the two nuclei are different

Solution:
Wavelength involved in the spectrum also depends on mass of nuclei apart from nuclear charge.

Topic: Physics, Atomic Physics, NEET
The wavelengths of K Î± X-rays of two metals A and B are 41875R and 1675R respectively, where R is Rydberg constant. The number of elements lying between A and B according to their atomic numbers is

Options:
A 3
B 6
C 5
D 4

The correct answer is:
4

Solution:
1λ=RZ-12×1-14⇒1875 R4=RZ1-1234⇒Z1=26
and 675R=RZ2-12·34⇒Z2=31
Hence the number of elements = 4

Topic: Physics, Atomic Physics, NEET
The wavelengths of two notes in the air are 36195 m and 36193 m. Each note produces 10 beats per second separately with a third note of fixed frequency. The velocity of sound in air in m s-1 is

Options:
A 330
B 340
C 350
D 360

The correct answer is:
360

Solution:
Beat frequency=v1~v2
Let the frequency of third note be n.
Then,
195v36-n=10 …i
And
n-193v36=10 …ii
Adding Eqs. (i) and (ii)
v18=20
⟹ v=360 m s-1

Topic: Physics, Waves and Sound, NEET
The weight of a body at earth's surface is W. At a depth halfway to the centre of the earth, it will be (assuming uniform density in the earth) -

Options:
A W
B W2
C W4
D W8

The correct answer is:
W2

Solution:
Due to depth gâ²=g 1-dReâ´ d=Re/2
so gâ²=g 1-Re/2Re=g/2
Now gâ² is half so weight is also half.

Topic: Physics, Gravitation, NEET
The weight of a body at the centre of earth is

Options:
A 9.8 m s-2
B 0
C 4.9Â m s-2
D 10Â m s-2

The correct answer is:
0

Solution:
We know that, on going below the earth surface, g decreases, which is given by
gâ²=g1-dRe .....(i)
where, d= depth
Re= Radius of earth.
At the centre of earth, d=Re [ â´ from Equation (i)]
gâ²=g1-ReRe
gâ²=0
Hence, weight of the body at the centre,
w=mgâ²
=mÃ0
=0

Topic: Physics, Gravitation, NEET
The weight of a body at the centre of the earth is

Options:
A 9.8 m s-2
B 0
C 4.9Â m s-2
D 10Â m s-2

The correct answer is:
0

Solution:
We know that, on going below the earth surface, g decreases, which is given by
gâ²=g1-dRe .....(i)
where, d= depth
Re= Radius of earth.
At the centre of earth, d=Re [ â´ from Equation (i)]
gâ²=g1-ReRe
gâ²=0
Hence, weight of the body at the centre,
w=mgâ²
=mÃ0
=0

Topic: Physics, Gravitation, NEET
The weight of a body on the surface of the earth is 12.6 N. When it is raised to a height half the radius of earth its weight will be

Options:
A 2.8 N

B 5.6 N

C 12.5 N

D 25.2 N

The correct answer is:
5.6 N

Solution:
Weight of body on the surface of earth mg=12.6 N
At height h, the value of gâ² is given by
gâ²=gR2(R+h)2
Now, h=R2
Weight at height h=mg49
=12.6Ã49=5.6 N

Topic: Physics, Gravitation, NEET
The weight of ethyl alcohol which must be added to 1.0 L of water so that the solution will freeze at 14°F is ( Kf of water = 1.86 K kg mol-1 )

Options:
A 263.11 g
B 247.31 g
C 236.11 g
D 281.01 g

The correct answer is:
247.31 g

Solution:
o C= o F-32 ×5 9
14°F=-10°C
So ΔT=10
ΔT=Kf×wB×1000MB×wA
10=1.86×wB×100046×1000
wB=247.31 g.

Topic: Chemistry, Solutions, NEET
The weight of silver (at wt. =108 ) displaced by a quantity of electricity which displaces 560 mL of O2 at STP will be
(Volume of 1 mole of gas at STP is 22.4 L)

Options:
A 54.9 g
B 5.4 g
C 10.8 g
D 108.0 g

The correct answer is:
10.8 g

Solution:
According to faraday's 2nd law wAgEAg=wO2EO2
wAg108=56022400Ã328
â´ wAg=10.8 g

Topic: Chemistry, Electrochemistry, NEET
The weight of silver (at.wt. =108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be

Options:
A 5.4 g
B 10.8 g
C 54.0 g
D 108.0 g

The correct answer is:
108.0 g

Solution:
nO2=560022400=14
WAg108×1=WO2MO2×42H2O→O2+4H++4e-
WAg108=14×4
WAg=108 g

Topic: Chemistry, Electrochemistry, NEET, NEET 2014
The Western Ghats have a greater amphibian diversity than the Eastern Ghats. This is an example of __________.

Options:
A Genetic diversity
B Delta diversity
C Ecosystem diversity
D Species diversity

The correct answer is:
Species diversity

Solution:
Species diversity: The diversity at the species level, for example, the Western Ghats have a greater amphibian species diversity than the Eastern Ghats. Ecological diversity: At the ecosystem level, India, for instance, with its deserts, rain forests, mangroves, coral reefs, wetlands, estuaries, and alpine meadows has a great ecological diversity.

Topic: Biology, Biodiversity and its Conservation, NEET
The wettability of a surface by a liquid depends primarily on

Options:
A viscosity
B surface tension
C density
D angle of contact between the surface and the liquid

The correct answer is:
angle of contact between the surface and the liquid

Solution:
The value of angle of contact determines whether a liquid will spread on the surface.

Topic: Physics, Mechanical Properties of Fluids, NEET, NEET 2013 (All India)
The wheel of a toy car rotates about an axis on the rough surface. Its angular frequency slows down from 400 rps to 200 rps in 2 s. Then its angular retardation in rad s-2 is

Options:
A 200 π
B 100 π
C 400 π
D None of these

The correct answer is:
200 π

Solution:
Given, Ï1=2ÏÃ(400) rad s-1
Ï2=2ÏÃ(200) rad s-1
Î± = 2 Ï 4 0 0 - 2 0 0 2 = 2 0 0 Ï radions Î± is the retardation.

Topic: Physics, Laws of Motion, NEET
The wheels on the old-time bicycle shown in diagram have radii of 60.0 cm. and 10.0 cm. If the larger wheel is rotating at 12.0 rad s-1, what is the angular speed of the smaller wheel?

Options:
A 12.0 rad s-1
B 60.0 rad s-1
C 72.0 rad s-1
D 2.0 rad s-1

The correct answer is:
72.0 rad s-1

Solution:
The linear velocity of both wheels will be the same
6 0 × 1 2 = 1 0 × ω
ω=72 rad s-1

Topic: Physics, Rotational Motion, NEET
The white fibres are chemically formed of

Options:
A Collagen
B Elastin
C Myosin
D Reticulin

The correct answer is:
Collagen

Solution:
White fibrous connective tissue are formed of collagen protein which changes to gelatin protein by boiling. It gives tensile strength.

Topic: Biology, Structural Organisation in Animals, NEET
The Wien's displacement law expresses the relation between:

Options:
A wavelength corresponding to maximum energy and temperature
B relation energy and wavelength
C temperature and wavelength
D colour of light and temperature

The correct answer is:
wavelength corresponding to maximum energy and temperature

Solution:
Using Wein's displacement law : the wavelength corresponding to maximum energy is inversely proportional to the abolute temperature of the body. i.e.
$\lambda_m \propto \frac{d}{T} \Rightarrow \lambda_m T=\text { constant }$

Topic: Physics, Thermal Properties of Matter, NEET, NEET 2002
The wild type E. coli cells are growing in a normal medium with glucose. They are transferred to a medium containing only lactose as sugar. Which of the following changes takes place?

Options:
A The lac operon is repressed
B All operons are induced
C The lac operon is induced
D E.coli cells stop dividing

The correct answer is:
The lac operon is induced

Solution:
If Escherichia coli bacteria grow in normal glucose medium and when transferred to a medium containing lactose, the lac operon is induced.

Topic: Biology, Molecular Basis of Inheritance, NEET
The wings of a bird and the wings of an insect are:

Options:
A Analogous structures and represent convergent evolution
B Phylogenetic structures and represent divergent evolution
C Homologous structures and represent convergent evolution
D Homologous structures and represent divergent evolution

The correct answer is:
Analogous structures and represent convergent evolution

Solution:
The structures in different organisms which are not similar anatomically though they perform similar functions are called as analogous organs. Morphologically they may or may not be similar which means that analogous structures may or may not look alike externally. The property of bearing analogous structures is called analogy. The analogous structures do not exhibit common origin. Unlike homology which indicates common ancestry, the analogy does not indicate common ancestry.

The wings of butterfly and of birds. Butterflies are the invertebrates whereas birds are vertebrates. The wings in both of them perform the common function of flying but the internal designs and components of these two types of wings are very different from one another. The wings look alike externally because they have a common use of flying. It is an example of convergent evolution.

Topic: Biology, Evolution, NEET, NEET 2015 (Phase 2)
The wings of pigeon, butterfly and bat show

Options:
A Divergent evolution
B Atavism
C Convergent evolution
D All of these

The correct answer is:
Convergent evolution

Solution:
The wings of pigeon, mosquito and bats are analogous structures i.e., these organs are anatomically different but functionally similar and are adapted for flying. Thus, they give evidence of convergent evolution.

Topic: Biology, Evolution, NEET
The wire of length l is bent into a circular loop of a single turn and is suspended in a magnetic field of induction B. When a current I is passed through the loop, the maximum torque experienced by it is

Options:
A 14ÏBIl2
B 14πBI2l
C 14ÏBIl
D 14ÏB2Il

The correct answer is:
14πBIl2

Solution:
When the wire of length l is bent into circular loop of radius R
l=2Ïrâr=l2Ï
When current I is passed through the loop, the torque acting on the loop.
Ï=nIAB
Ï=IÃBÃÏr2
=IB Ïl2Ï2=IBl24Ï=14ÏBIl2

Topic: Physics, Magnetic Effects of Current, NEET