datavorous/entrance-exam-dataset huggingface dataset:
If ' + ' sign is assigned to beneficial interaction, ' – ' sign to detrimental and ' 0 ' sign to neutral interaction, then the population interaction represented by '+' '-' refers to

Options:
A Mutualism
B Amensalism
C Commensalism
D Parasitism

The correct answer is:
Parasitism

Solution:
Name of interaction	Species A	Species B

Mutualism	+	+

Protocooperation	+	+

Amensalism	-	0

Commensalism	+	0

Competition	-	-

Parasitism	+	-

Predation	+	-

Topic: Biology, Organisms and Populations, NEET, NEET 2016 (Phase 2)
If silver crystallizes in an fcc lattice with an edge length of 4.07 × 10–8cm and a density of 10.5 g/cm³, what is the atomic mass of silver?

Options:
A 107.87 g/mol
B 122.45 g/mol
C 134.47 g/mol
D 167.97 g/mol

The correct answer is:
107.87 g/mol

Solution:
Correct Option is : (A)
107.87 g/mol

Topic: Chemistry, Solid State, NEET
If soap has high alkali content it irritates skin. How can the amount of excess alkali be determined? What can be the source of excess alkali?

Options:
A The amount of excess alkali can be determined by taste.
B The amount of excess alkali can be determined by the soap's color.
C Acid-base titration can be used to determine the excess amount of alkali in soap. The excess alkali left after hydrolysis of oil can be the source of alkalinity in soap.
D The source of excess alkali is usually natural oils in the soap.

The correct answer is:
Acid-base titration can be used to determine the excess amount of alkali in soap. The excess alkali left after hydrolysis of oil can be the source of alkalinity in soap.

Solution:
Correct Option is : (C)
Acid-base titration can be used to determine the excess amount of alkali in soap. The excess alkali left after hydrolysis of oil can be the source of alkalinity in soap.

Topic: Chemistry, Chemistry in Everyday Life, NEET
If specific heat of a substance is infinite, it means

Options:
A heat is given out
B heat is taken in
C no change in temperature takes place whether heat is taken in or given out
D all of these

The correct answer is:
no change in temperature takes place whether heat is taken in or given out

Solution:
Specific heat of a substance is infinite, therefore no change in temperature takes place whether heat is taken in or given out
C=ΔQnΔT
If C→∞
∴ΔT→0

Topic: Physics, Thermodynamics, NEET
If specific heat of a substance is infinite, it means

Options:
A heat is given out
B heat is taken in
C no change in temperature takes place whether heat is taken in or given out
D all of the above

The correct answer is:
no change in temperature takes place whether heat is taken in or given out

Solution:
We know that
Q=mc·Δθ
⇒Δθ=Qm·c ;
When c=∞,
⇒Δθ=0
⇒Q=0

Topic: Physics, Thermal Properties of Matter, NEET
If temperature of an object is 140 Â°F, then its temperature in centigrade is

Options:
A 105 °C
B 32 °C
C 140 °C
D 60 °C

The correct answer is:
60 °C

Solution:
Relation between °C and °F,
C5=F-329
⇒ C5=140-329
⇒C=60 °C

Topic: Physics, Thermal Properties of Matter, NEET
If the air of weight w is filled in an empty balloon which weighs w1, the weight of the balloon will become w2. Suppose the density of the air inside and outside the balloon is same, then

Options:
A w2=w1+w
B w2=w1w
C w2=w1
D w2=w1-w

The correct answer is:
w2=w1

Solution:
The apparent weight of the balloon =w2
Apparent weight = real weight - upthrust
∴ w2= real weight −w
But Real weight =w1+w
w2=w1+w−w=w1
w2=w1

Topic: Physics, Mechanical Properties of Fluids, NEET
If the angle between the vector $\vec{A}$ and $(\vec{B} \times \vec{A}) \cdot \vec{A}$ is $\theta$, the value of the product $(\vec{B} \times \vec{A}) \cdot \vec{A}$ is equal to:

Options:
A $B A^2 \sin \theta$
B $B A^2 \cos \theta$
C $B A^2 \sin \theta \cos \theta$
D zero

The correct answer is:
zero

Solution:
$(\vec{B} \times \vec{B}) \vec{A}=(B A \sin \theta)(\vec{n} \cdot \vec{A})=0$
Since $n$ is perpendicular to both $\vec{A}$ and $\vec{B}$.

Topic: Physics, Mathematics in Physics, NEET, NEET 2005
If the angle of minimum deviation is of 60° for an equilateral prism, then the refractive index of the material of the prism is

Options:
A 1.41
B 1.5
C 1.6
D 1.73

The correct answer is:
1.73

Solution:
μ=sin⁡A+δm2sin⁡A2
For equilateral prism, ∠A=60°
μ=sin⁡60°+60°2sin⁡60°2=sin⁡60°sin⁡30°=3212=3=1.73

Topic: Physics, Ray Optics, NEET
If the assumption that there is no force of attraction between the molecules of a gas is correct, what will be the consequences?

Options:
A All gases will be ideal gases
B the gases will never liquefy when cooled and compressed
C Gases will have definite volume
D Gases will occupy a definite space

The correct answer is:
the gases will never liquefy when cooled and compressed

Solution:
It means thegas molecules will never come closer under any conditions. Thus they will never liquefy when cooled and compressed.

Topic: Chemistry, States of Matter, NEET
If the balance length corresponding to points B and C is 40 cm on the potentiometer wire, the balance length corresponding to points C and D is

Options:
A 25 cm
B 32 cm
C 40 cm
D 64 cm

The correct answer is:
32 cm

Solution:
VB-VC=I×5=ϕ×40 .... (1)
∴ VC-VD=I×4=ϕ×l .... (2)
eq.1eq.2=54=40l
∴ l=40×45=32 cm

Topic: Physics, Current Electricity, NEET
If the balance length corresponding to points B and C is 40 cm on the potentiometer wire, the balance length corresponding to points C and D is

Options:
A 25Â cm
B 32 cm
C 50 cm
D 64Â cm

The correct answer is:
32 cm

Solution:
According to the question
VB â VC=I Ã 5 =Ï Ã 40 ....(1)
â´ VC â VD=I Ã 4 =Ï Ãl ....(2)
from (1) and (2)
â54=40lâ´l =40Ã45= 32 cm

Topic: Physics, Current Electricity, NEET
If the base sequence in one chain of DNA is GCATG, what shall be the sequence in the replicated complementary strand

Options:
A GCATG
B CGTAC
C ATGCG
D GCATC

The correct answer is:
CGTAC

Solution:
The replicated complementary strand will have sequence CGTAC because A binds with T and G binds with C.

Topic: Biology, Molecular Basis of Inheritance, NEET
If the B–Cl bond has a dipole moment, explain why the BCl₃ molecule has a zero dipole moment.

Options:
A The three B–Cl bonds in BCl₃ are arranged symmetrically around the boron atom, canceling out any individual dipole moments and resulting in a net zero dipole moment for the molecule.
B The boron atom in BCl₃ is less electronegative than chlorine, leading to a net dipole moment of zero for the molecule.
C The dipole moments of the individual B–Cl bonds in BCl₃ cancel each other out due to their equal magnitudes and opposite directions.
D The lone pair of electrons on boron in BCl₃ causes a cancellation of dipole moments.

The correct answer is:
The boron atom in BCl₃ is less electronegative than chlorine, leading to a net dipole moment of zero for the molecule.

Solution:
Correct Option is : (B)
The boron atom in BCl₃ is less electronegative than chlorine, leading to a net dipole moment of zero for the molecule.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
If the binding energy per nucleon in 3Li7 and 2He4 nuclei are respectively 5.60 MeV and 7.06 MeV, then the energy of the proton in the reaction 3Li+pâ22He 4 is

Options:
A 19.6 MeV

B 2.4 MeV

C 8.4 MeV

D 17.3 MeV

The correct answer is:
17.3 MeV

Solution:
Applying principle of energy conservation.
Energy of proton = total BE of 2 Î±-energy of Li7
=8Ã7.06-7Ã5.6
=56.48-39.2=17.28 MeV

Topic: Physics, Nuclear Physics, NEET
If the bio-resource of an organization is accessed without authorization, it will come under -

Options:
A Biopiracy
B Biopatent
C Exploitation
D Traditional piracy

The correct answer is:
Biopiracy

Solution:
The unauthorized use or reproduction of work done of an individual or organization by some other will be deemed as piracy. When this piracy is done in regards to biological resources, it is termed as biopiracy. Many nations are taking steps to prevent the biopiracy and exploitation of traditional knowledge by other rich multinational companies.

Topic: Biology, Biotechnology and Its Applications, NEET
If the birth rate is 100, the death rate is 10 and the number of individuals in a population group is 1000, then what will be the intrinsic rate of natural increase of the population?

Options:
A 900
B 90
C 1090
D 890

The correct answer is:
90

Solution:
The increase in the number of individuals in a particular time period is termed as ‘birth rate’ or ‘natality’, while the individuals dying over a time period are known as ‘mortality’ or ‘death rate’.
Birth rate = 100
Death rate = 10
Number of individuals in a population = 1000
The intrinsic rate of natural increase is = 100 – 10 = 90

Topic: Biology, Organisms and Populations, NEET
If the bond energies of H-H, Br-Br, and H-Br are 433, 192 and 364 kJ mol-1 respectively, the âHo for the reaction H2g+Br2gâ2HBrg is

Options:
A -261Â kJ
B +103Â kJ
C +261Â kJ
D -103 kJ

The correct answer is:
-103 kJ

Solution:
H2g+Br2gâ2HBrg
Enthalpy change for this reaction will equal to the difference in the energy consumed for breaking bonds of reactants and energy released when bonds of products are made
Enthalpy = Sum of bond energies broken - sum of bond energies formed
âHo=B Ereactant-B Eproduct
=433+192-2Ã364
=625-728=-103 kJ

Topic: Chemistry, Thermodynamics (C), NEET
If the bond energies of $\mathrm{H}-\mathrm{H}, \mathrm{Br}-\mathrm{Br}$, and $\mathrm{H}-\mathrm{Br}$ are 433,192 and $364 \mathrm{~kJ} /\mathrm{mol}^{-1}$ respectively, the $\Delta \mathrm{H}^{\circ}$ for the reaction $\mathrm{H}_{2(g)}+\mathrm{Br}_{2(g)} \rightarrow 2 \mathrm{HBr}_{(g)}$ is:

Options:
A $-261 \mathrm{~kJ}$
B $+103 \mathrm{~kJ}$
C $+261 \mathrm{~kJ}$
D $-103 \mathrm{~kJ}$

The correct answer is:
$-103 \mathrm{~kJ}$

Solution:
$\mathrm{H}-\mathrm{H}+\mathrm{Br}-\mathrm{Br} \rightarrow 2 \mathrm{H}-\mathrm{Br}$
$$
\begin{array}{rrr}
433+192 & 2 & \times 364 \\
=625 & =728
\end{array}
$$
Energy absorbed Energy released
Net energy released $=\Sigma \mathrm{H}_{\mathrm{R}}-\Sigma \mathrm{H}_{\mathrm{p}}$ $=625-728=-103 \mathrm{~kJ}$.
Related Theory
Fluorine has high bond energy because it is smallest among these molecules so it is tightly bonded to other atoms due to greater nuclear charge.

Topic: Chemistry, Thermodynamics (C), NEET, NEET 2004
If the bulk modulus of water is 2100 MPa, then speed of sound in water is (take density of water, Ï=1000 kg/m3)

Options:
A 1320 m/s
B 1450 m/s
C 1580 m/s
D 1630 m/s

The correct answer is:
1450 m/s

Solution:
Speed of sound in water is given by,

v=Bρ
∴ v = 2100 × 10 6 1000 = 2.1 × 10 6
or v=1.45×103=1450 m/s

Topic: Physics, Waves and Sound, NEET
If the cell is placed in a hypertonic solution, what will happen?

Options:
A Endosmosis
B Exosmosis
C Deplasmolysis
D No change

The correct answer is:
Exosmosis

Solution:
Osmosis is the process which takes place due to difference in the concentration of solutions. The movement of molecules always takes place from a solution of less concentration to a solution of high concentration. Hypertonic solution is one which has a higher concentration of solute as compared to the other solution, therefore if a cell is placed in a hypertonic solution it will lose water due to exosmosis ( transfer of molecules outside the cell) and become a plasmolysed cell(shrinking of the cell).

Topic: Biology, Transport in Plants, NEET
If the change in the value of g at a height h above the surface of the earth is the same as at a depth x below it. When both x and h are much smaller than the radius of the earth. Then

Options:
A x=h
B x=2h
C x=h2
D x=h2

The correct answer is:
x=2h

Solution:
At height h ,acceleration due to gravity gh=g1-2hR
At depth d ,acceleration due to gravity gd=g1-dR=g1-xR
Comparing gh=gx
⇒2h=x

Topic: Physics, Gravitation, NEET
If the chromosome number in the root cell of Zea mays is 20, then what would be the chromosome number in the cell of (i) radicle, (ii) hypocotyls, (iii) epiblast, (iv) aleurone layer and (v) scutellum, respectively?

(i)	(ii)	(iii)	(iv)	(v)

1	20	30	20	30	20

2	20	20	20	30	20

3	20	30	30	30	20

4	20	20	20	20	20

Options:
A 1
B 2
C 3
D 4

The correct answer is:
2

Solution:
Maize, Zea mays, is a monocotyledonous plant under the group of Angiosperm. It displays double fertilization, where a 2n zygote forms in first fertilization and a 3n primary endosperm nucleus forms in second fertilization which results in formation of aleurone layer.
Given maize plant has 20 chromosomes in root cell which is diploid. 2n=20; n=10 .
Radicle, hypocityle, scutellum, epiblast are derivatives of embryo and will have 2n=20 chromosomes each.
Aleurone layer is 3n, thus, it will have 30 chromosomes.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
If the coefficient of friction between the wedge A and block B shown in the figure is Î¼, then the maximum possible horizontal acceleration of A for which B doesn't slip is [angle of inclination of wedge = 45Â°]

Options:
A μg
B g1+μ1-μ
C gμ
D g1-μ1+μ

The correct answer is:
g1+μ1-μ

Solution:
FBD of block B w.r.t. wedge A, for maximum 'a':

Perpendicular to wedge:
Σfy=(mgcosθ+masinθ-N)=0
and Σfx=mgsinθ+μN-macosθ=0 (for maximum a)
⇒ mgsinθ+μ(mgcosθ+masinθ)-macosθ=0
⇒ a=(gsinθ+μgcosθ)cosθ-μsinθ

for θ=45°

a=gtan45°+μcot45°-μ; a=g1+μ1-μ

Topic: Physics, Laws of Motion, NEET
If the coils of a transformer are made up of thick wire, then

Options:
A eddy current losses will be more
B magnetic flux leakage is reduced
C Joule heating loss is increased
D Joule heating loss is reduced

The correct answer is:
Joule heating loss is reduced

Solution:
When the wire is thick, its resistance decreases. Therefore, joule heating losses are reduced.

Topic: Physics, Alternating Current, NEET
If the cold junction of thermocouple is kept at $0^{\circ} \mathrm{C}$ and the hot junction is kept at $T^{\circ} \mathrm{C}$, then the relation between neutral temperature $\left(T_n\right)$ and temperature of inversion $(T)$.

Options:
A $T_n=2 T$
B $T_n=T_i-T$
C $T_n=T_i+T$
D $T_n=\frac{T}{2}$

The correct answer is:
$T_n=\frac{T}{2}$

Solution:
$\because T_n=\frac{T_C+T_1}{2}$ and $T_C=0^{\circ} \mathrm{C}$ $\therefore T_n=\frac{T_1}{2}$

Topic: Physics, Thermal Properties of Matter, NEET, NEET 2007
If the combustion of 1g of graphite produces 20.7 kJ of heat, what will be molar enthalpy change? Give the significance of sign also.

Options:
A ∆H = – 2.48 × 103kJmol–1, Negative value of ∆H ⇒ exothermic rxn
B ∆H = – 2.48 × 102kJmol–1, Negative value of ∆H ⇒ exothermic reaction
C ∆H = – 2.48 × 102kJmol–1, Negative value of ∆H ⇒ endothermic reaction
D ∆H = – 3.67 × 102kJmol–1, Negative value of ∆H ⇒ exothermic reaction

The correct answer is:
∆H = – 2.48 × 102kJmol–1, Negative value of ∆H ⇒ exothermic reaction

Solution:
Correct Option is : (B)
∆H = – 2.48 × 102kJmol–1, Negative value of ∆H ⇒ exothermic reaction

Topic: Chemistry, Thermodynamics (C), NEET
If the compressibility of water is σ per unit atmospheric pressure, then the decrease in volume V due to atmospheric pressure P will be -

Options:
A σP/V
B σPV
C σ/PV
D σV/P

The correct answer is:
σPV

Solution:
K=PΔVV or 1K=ΔV/VP
or σ=ΔVPV or ΔV=σPV.

Topic: Physics, Mechanical Properties of Solids, NEET
If the concentration of $\mathrm{OH}^{-}$ions in the reaction $\mathrm{Fe}(\mathrm{OH})_3(s) \rightleftharpoons \mathrm{Fe}^{3+}(a q)+3 \mathrm{OH}(a q)$ is decreased by $\frac{1}{4}$ times, then equilibrium concentration of $\mathrm{Fe}^{3+}$ will increase by

Options:
A 8 times
B 16 times
C 64 times
D 4 times

The correct answer is:
64 times

Solution:
Key Idea : The concentration of solids taken to be unity.
$\begin{aligned}
& \mathrm{Fe}(\mathrm{OH})_3(s) \rightleftharpoons \mathrm{Fe}^{3+}(a q)+3 \mathrm{OH}^{-}(a q) \\
& \therefore \quad K=\left[\mathrm{Fe}^{3+}\right]\left[\mathrm{OH}^{-}\right]^3
\end{aligned}$
Hence, if $\mathrm{OH}^{-}$ion concentration is decreased by $\frac{1}{4}$ times, then equilibrium concentration of $\mathrm{Fe}^{3+}$ will increase by 64 times.

Topic: Chemistry, Chemical Equilibrium, NEET, NEET 2008 (Screening)
If the critical angle for total internal reflection from a medium to vacuum is 30° , the velocity of light in the medium is

Options:
A 3×108 m s-1
B 1.5Ã108 m s-1
C 6×108 m s-1
D 3×108 m s-1

The correct answer is:
1.5Ã108 m s-1

Solution:
The relative refractive index of denser medium with respect to the rarer medium is

μdr=μdμr

sin⁡ic=1μdr=μrμd=vdvr
sin⁡30o=Vd3×108
⇒ vd=1.5×108 m s-1

Topic: Physics, Ray Optics, NEET
If the critical angle for total internal reflection from a medium to vacuum is 45°, then velocity of light in the medium is,

Options:
A 1.5×108 m s-1
B 32×108 m s-1
C 2×108 m s-1
D 3×108 m s-1

The correct answer is:
32×108 m s-1

Solution:
Use the concept of critical angle in terms of the refractive index of a medium with respect to another medium, sinθC=1μ,

⇒μ=1sinθC=1sin45°=1(1/2)=2, now we know that the ratio of the speed of light in vacuum and speed of light in a medium is called the refractive index of the medium, μ=cv⇒v=cμ=3×1082 m s-1.

Topic: Physics, Ray Optics, NEET, NEET 2020 (Phase 2)
If the current in the toroidal solenoid increases uniformly from zero to 6.0 A in 3.0 Î¼s. Self-inductance of the toroidal solenoid is 40 Î¼H. The magnitude of self-induced emf is

Options:
A 80  V
B 160  V
C 24  V
D 48  V

The correct answer is:
80  V

Solution:
Current in toroidal solenoid increases uniformly from 0 to 6.0 A in 3.0 Î¼s.
Magnitude of self-induced emf is given by
Îµ=Ldidt [Symbols have usual meanings]
=40Ã10-66-03.0Ã10-6=80 V

Topic: Physics, Electromagnetic Induction, NEET
If the current through an inductor of 2 H is given by I=tsint A, then the voltage across the inductor is

Options:
A cost+tsint
B 2tcost+2sint
C tcost+sint
D 2tsint+2cost

The correct answer is:
2tcost+2sint

Solution:
eL=Ldidt
=Ltcos⁡t+sin⁡t L=2 H
=2tcos⁡t+2sin⁡t

Topic: Physics, Alternating Current, NEET
If the cyclotron oscillator frequency is 16 MHz , then what should be the operating magnetic field for accelerating the proton of mass 1.67Ã10-27 kg ?

Options:
A 0.334π T
B 3.34π T
C 33.4π T
D 334π T

The correct answer is:
0.334π T

Solution:
Given,
Frequency of cyclotron oscillator =16 MHz
v=16×106 Hz
Mass of proton, mp=1.67×10-27
The cyclotron frequency,
v=Bq2πm
Where B= Required magnetic field
B=v×2πmq
=16×106×2×π×1.67×10-271.6×10-19=0.334π T

Topic: Physics, Magnetic Effects of Current, NEET
If the de-Broglie wavelength is Î»0 for protons accelerated through 100 V, then the de-Broglie wavelength for alpha particles accelerated through the same voltage will be

Options:
A λ0
B λ02
C λ022
D none of these

The correct answer is:
λ022

Solution:
De-Broglie wavelength is Î»=h2mK=h2mqV
Therefore, de-Broglie wavelength for protons.
Î»0=h2mpeV0
and de-Broglie wavelength for alpha particles
Î»′=h24mp2eV0
Î»0Î»′=8=22
Î»′=Î»022

Topic: Physics, Atomic Physics, NEET
If the de-Broglie wavelength of a proton is 10-13 m, the electric potential through which it must have been accelerated is

Options:
A 4 . 0 7 × 1 0 4 V
B 8 . 2 × 1 0 4 V
C 8 . 2 × 1 0 3 V
D 4 . 0 7 × 1 0 5 V

The correct answer is:
8 . 2 × 1 0 4 V

Solution:
λ = h&ApplyFunction; 2 mq V&ApplyFunction;
1 0 - 1 3 2 = 6 . 6 × 1 0 - 3 4 2 2 × 1 . 6 7 × 1 0 2 7 × 1 . 6 × 1 0 - 1 9 V&ApplyFunction;
V&ApplyFunction; = 8 . 2 × 1 0 4 volt

Topic: Physics, Dual Nature of Matter, NEET
If the degree of freedom of a gas molecule is f, then the ratio of two specific heats is given by

Options:
A 2f+1
B 1-2f
C 1+1f
D 1-1f

The correct answer is:
2f+1

Solution:
η=CpCv=1+2n=1+2f

Topic: Physics, Kinetic Theory of Gases, NEET
If the density of a planet is constant, then the curve between the value of g on its surface and its radius r will be -

Options:
A
B
C
D

The correct answer is:

Solution:
We know that g=GMR2=Gρ43πR3R2=43πGρR
this mean g increases linearly with increase in R, keeping density constant, hence graph is straight line

Topic: Physics, Gravitation, NEET
If the density of methanol is 0.793 kg L–1, what is its volume needed for making 2.5 L of its 0.25 M solution?

Options:
A 27.65 mL
B 25.22 mL
C 23.45 mL
D 21.74 mL

The correct answer is:
25.22 mL

Solution:
Correct Option is : (B)
25.22 mL

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
If the density of some lake water is 1.25g mL–1and contains 92 g of Na+ions per kg of water, Calculate the molarity of Na+ions in the lake.

Options:
A 5 M
B 7.5 M
C 3.2 M
D 9 M

The correct answer is:
5 M

Solution:
Correct Option is : (A)
5 M

Topic: Chemistry, Solutions, NEET
If the diameter of a carbon atom is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across length of scale of length 20 cm long

Options:
A 2.11 × 109
B 2.56 × 109
C 1.33 × 109
D 0.45 × 109

The correct answer is:
1.33 × 109

Solution:
Correct Option is : (C)
1.33 × 109

Topic: Chemistry, Structure of Atom, NEET
If the diameter of a cylinder is 12.6Â±0.1 cm and its height is 34.2Â±0.1 cm, then find the volume of the cylinder to the nearest significant figure.

Options:
A 4264.4Â±81Â cm3
B 4260Â±81Â cm3
C 4300Â±80Â cm3
D 4260Â±80 cm3

The correct answer is:
4260Â±80 cm3

Solution:
V=πd2h4=π412.6234.2 cm3
dVV=2ddd+dhh
Converting to errors,
∆VV=2∆dd+∆hh
∆V4260=20.112.6+0.134.2
⇒∆V=80 cm3
V=4260±80 cm3

Topic: Physics, Units and Dimensions, NEET
If the diameter of the afferent renal arteriole is decreased and that of the efferent renal arteriole is increased, the ultrafiltration will

Options:
A be faster
B be slower
C not takes place
D takes place with the same speed

The correct answer is:
be slower

Solution:
During ultrafiltration in the nephrons, the diameter of the afferent (incoming) arteriole will be greater than that of the efferent (outgoing) arteriole. This increases the glomerulus blood pressure and helps to force the components of the blood get out of the glomerular capillaries.
If the diameter of the afferent renal arteriole is decreased and that of efferent renal arteriole is increased, the process of ultrafiltration gets hampered and will be slower. The actual pressure gradient will not be observed, and the filtration of all the components will not be possible.

Topic: Biology, Excretory Products and their Elimination, NEET
If the dimensions of a physical quantity are given by $\mathrm{M}^{\mathrm{a}} \mathrm{L}^{\mathrm{b}} \mathrm{T}^c$, then the physical quantity will be

Options:
A pressure if $\mathrm{a}=1, \mathrm{~b}=-1, \mathrm{c}=-2$
B velocity if $a=1, b=0, c=-1$
C acceleration if a $=1, b=1, c=-2$
D force if $\mathrm{a}=0, \mathrm{~b}=-1, \mathrm{c}=-2$

The correct answer is:
pressure if $\mathrm{a}=1, \mathrm{~b}=-1, \mathrm{c}=-2$

Solution:
(i) Dimensions of velocity $=\left[\mathrm{M}^0 \mathrm{~L}^1 \mathrm{~T}^{-1}\right]$ Here, $a=0, b=1, c=-1$
(ii) Dimensions of acceleration $=\left[\mathrm{M}^0 \mathrm{~L}^1 \mathrm{~T}^{-2}\right]$
Here, $\quad a=0, b=1, c=-2$
(iii) Dimensions of force $=\left[\mathrm{M}^1 \mathrm{~L}^1 \mathrm{~T}^{-2}\right]$
Here, $a=1, b=1, T=-2$
(iv) Dimensions of pressure $=\left[\mathrm{M}^1 \mathrm{~L}^{-1} \mathrm{~T}^{-2}\right]$
$\therefore$ Here, $\quad \mathrm{a}=1, \mathrm{~b}=-1, \mathrm{c}=-2$
$\therefore$ The physical quantity is pressure.

Topic: Physics, Units and Dimensions, NEET, NEET 2009 (Screening)
If the diploid chromosome number in a flowering plant is 12, then which one of the following will have only 6 chromosomes?

Options:
A Endosperm
B Leaf cells
C Cotyledons
D Synergids

The correct answer is:
Synergids

Solution:
Synergids are formed by megaspore, which is a haploid structure. Thus, synergids are haploid and possess 6 chromosomes.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
If the dipole moment of AB molecule is given by 1.6 D and A–B the bond length is 1 A o then % covalent character of the bond is

Options:
A 25
B 33.33
C 66.66
D 75

The correct answer is:
33.33

Solution:
Î¼Cal=4.8Ã10-10e.s.uÃ10-8cm
4.8× 10 −18  esu × cm
=4.8D
Hence, % ionic character =  1.6 4.8  × 100
=33.33%

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET