datavorous/entrance-exam-dataset huggingface dataset:
If the solubility product of CuS is 6 × 10–16, what is the maximum molarity of CuS in aqueous solution?

Options:
A 9.36 x 10-8M
B 5.64 x 10-8M
C 2.45 x 10-8M
D 7.75 x 10-8M

The correct answer is:
2.45 x 10-8M

Solution:
Correct Option is : (C)
2.45 x 10-8M

Topic: Chemistry, Solutions, NEET
If the speed of light is 3.0 × 108m s–1, calculate the distance covered by light in 2.00 ns.

Options:
A 0.745m
B 0.549m
C 0.645m
D 0.600m

The correct answer is:
0.600m

Solution:
Correct Option is : (D)
0.600m

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
If the spin-only magnetic moment of [MnBr4]2–is 5.9 BM. Predict the geometry of the complex Ion?

Options:
A Tetrahedral
B Octahedral
C Square Planar
D Linear

The correct answer is:
Tetrahedral

Solution:
Correct Option is : (A)
Tetrahedral

Topic: Chemistry, Coordination Compounds, NEET
If the stock contains 48 chromosomes and the scion contains 30 chromosomes, then how many chromosomes are present in the root and egg cell of the resultant plant, respectively?

Options:
A 48 and 15
B 15 and 48
C 30 and 24
D 24 and 15

The correct answer is:
48 and 15

Solution:
Grafting is an artificial propagation technique where two different plants are grafted together. One plants rooted stock is joined with the non-rooted stem of the other plant(scion). The cambium content must be compatible in this process to get a successful graft. The two parts of plant grow and develop completely without any mixing or hybridization.
The stock part having 48 chromosomes will show 48 chromosomes in the root cell. The scion will develop flower and gametic cells which will have half the genetic content. Since, scion part has 30 chromosomes, the egg cell will have 15 chromosomes in it.

Topic: Biology, Reproduction in Organisms, NEET
If the stroke volume of an athlete is 100 ml and the heart beat rate is 82/min, what will be the cardiac output?

Options:
A 8.5 L
B 8 L
C 8.3 L
D 8.2 L

The correct answer is:
8.2 L

Solution:
Cardiac output (CO): It is the amount of blood that each ventricle pumps during one minute.
Cardiac output (CO) = Stroke volume (SV) × Heart beat rate (HR)
= 100 ml × 82/min.
= 8200 ml (8.2 litre).

Topic: Biology, Body Fluids and Circulation, NEET
If the sugar level of blood is too high, it can be reduced immediately by

Options:
A oral insulin
B oral glucagon
C intravenous insulin
D intravenous glucagon

The correct answer is:
intravenous insulin

Solution:
Insulin and Glucagon are pancreatic hormones that control sugar metabolism. Insulin is responsible for lowering the blood sugar level as it increases cellular uptake of glucose. Thus it transports glucose from the blood into the cells. In IDDM (Insulin dependent diabetes mellitus) the insulin production is impaired due to which glucose accumulates in the blood. This will increase the viscosity of blood and will hamper the blood flow. This condition can be corrected by intravenous insulin and thus insulin will directly enter the blood and thus reduce the blood sugar. Insulin cannot be given orally because insulin is proteinaceous hormone and proteins easily dissolve in the stomach.

Topic: Biology, Chemical Coordination and Integration, NEET
If the temperature of the sink of a Carnot engine having an efficiency 16 is reduced by 62Â°C,then its efficiency is doubled. Find the temperatures of the sink and source respectively.

Options:
A 124°C,62°C
B 99°C,37°C
C 37Â°C,99Â°C
D 62°C,124°C

The correct answer is:
37°C,99°C

Solution:
TC= Temperature of sink

TH = Temperature of source

16=1-TCTH

TCTH=1-TC-(62)TH=1-TCTH+(62)TH

13=16+62TH

62TH=16 TH=372K

16=1-TC372

Tc372=56

TC=5×3726=310K

Topic: Physics, Thermodynamics, NEET
If the temperature of the sun were to increase from T to 2T and its radius from R to 2R, the ratio of radiant energy received on earth to what it was previously, will be

Options:
A 4
B 16
C 32
D 64

The correct answer is:
64

Solution:
From Stefan law, the energy radiated by sun is given by. P=ÏeAT4, assuming e = 1 for sun.
In Ist case, P1=ÏeÃ4ÏR2ÃT4
In 2nd case, P2=ÏeÃ4Ï2R2Ã(2T4)
= ÏeÃ4ÏR2ÃT4Ã64=64P1
The rate at which energy is received by earth is,
E=P4ÏRSE2ÃAE
where AE = area of earth
RSE = distance between sun and earth
So, In Ist case, E1= P14ÏRSE2ÃAE
E2=P24ÏRSE2ÃAE=64E1

Topic: Physics, Thermal Properties of Matter, NEET
If the temperature, volume, and pressure of a fixed amount of gas change from T1, V1, and p1 to T2, V2, and p2, what can be written based on the ideal gas equation?

Options:
A p1V1/T1 = p2V2/T2
B p1T1/V1 = p2T2/V2
C p1V1 = p2V2
D T1V1/p1 = T2V2/p2

The correct answer is:
p1V1/T1 = p2V2/T2

Solution:
The ideal gas equation can be written as p1V1/T1 = p2V2/T2 when the temperature, volume, and pressure of a fixed amount of gas change.

Topic: Chemistry, States of Matter, NEET
If the total amount of adenine and thymine in a double-stranded DNA is 60% then, the amount of guanine in this DNA will be

Options:
A 15%
B 20%
C 30%
D 40%

The correct answer is:
20%

Solution:
If the amount of adenine+ thymine = 60%, then the amount of guanine + cytosine will be 40%. So, the amount of guanine in this DNA will be = 20%

Topic: Biology, Molecular Basis of Inheritance, NEET
If the total energy of a simple harmonic oscillator is E, then its potential energy, when it is halfway to its endpoint will be

Options:
A 23E
B 18E
C 14E
D 12E

The correct answer is:
14E

Solution:
The potential energy of a simple harmonic oscillator
=12mÏ2y2
For y=a2, P.E.=12mÏ2a24
âP.E.=1412mÏ2a2=E4

Topic: Physics, Oscillations, NEET
If the two genes are having % of recombination less than 50%, then the progeny of F2 generation will show

Options:
A higher number of the recombinant types
B segregation in the expected 9 : 3 : 3 : 1 ratio
C segregation in 3 : 1 ratio
D higher number of the parental types

The correct answer is:
higher number of the parental types

Solution:
If the % of recombination is less than 50%, then the genes are said to be linked. If two genes are present close on the chromosomal linkage map than they show strong linkage as a result frequency of crossing over between the genes decreases. As a result number of parental types is more than the recombinant type. The strength of linkage is inversely proportional to the distance between two genes present on the same chromosome. Linked genes can not show independent assortment.

Topic: Biology, Principles of Inheritance and Variation, NEET
If the uncertainty in the position of an electron is 10-10 m, then what be the value of uncertainty in its momentum in kg m s-1? h=6.62Ã10-34 J s

Options:
A 1.05Ã10-24
B 1.01Ã10-24
C 1.09×10-24
D 1.07Ã10-24

The correct answer is:
1.05×10-24

Solution:
ΔxΔP≥h2π
⇒ ΔP≥6.62×10-342×3.14×10-10
ΔP≥1.05×10-24
=1.0536×10-24 kg m s-1

Topic: Physics, Dual Nature of Matter, NEET
If the value of an equilibrium constant for a particular reaction is 1.6×1012, then at equilibrium the system will contain:

Options:
A All reactants
B Mostly reactants
C Mostly products
D Similar amounts of reactants and products

The correct answer is:
Mostly products

Solution:
For any reaction of equilibrium
K=ProductxReactant y if K is 1.6×1012 (very high)
Then equilibrium mixture shall mostly contain products.

Topic: Chemistry, Chemical Equilibrium, NEET, NEET 2015 (Phase 1)
If the value of an equilibrium constant for a particular reaction is 1.8×1012, then at equilibrium the system will contain

Options:
A mostly reactants
B mostly products
C similar amounts of reactants products
D all reactants

The correct answer is:
mostly products

Solution:
The value of equilibrium constant for reaction K=1.8×1012
As the value of K is very high so the system will contain mostly products at equilibrium because the reaction will be near completion.

Topic: Chemistry, Chemical Equilibrium, NEET
If the value of g acceleration due to gravity at the earth surface is 10 m s-2. Its value in m s-2 at the centre of the earth, which is assumed to be a sphere of radius R metre and uniform mass density is

Options:
A 5
B Zero
C 10
D 1

The correct answer is:
Zero

Solution:
The value of g decreases gradually towards the center of the earth and becomes zero at the center.

The value of g at center of earth = 0 m/s2

Topic: Physics, Gravitation, NEET
If the vapour pressure of pure water at 25Â°C is 23.8 mmHg, then calculate the vapour pressure lowering caused by the addition of 100 g of sucrose (molecular mass =342 g/mol ) to 1000 g of water

Options:
A 00.12 mmHg
B 0.125 mmHg
C 1.15 mmHg
D 1.25 mmHg

The correct answer is:
0.125 mmHg

Solution:
Given molecular mass of sucrose =342
Moles of sucrose =100342=0.292 mole
Moles of water N=100018=55.5 moles and
Vapour pressure of pure water P0=23.8 mmHg
According to Raoultâs law ÎPP0=nn+NâÎP23.8=0.2920.292+55.5
ÎP=23.8Ã0.29255.792=0.125 mmHg .

Topic: Chemistry, Solutions, NEET
If the velocity of a particle is υ=At+Bt2, where A and B are constants, then the distance travelled by it between 1  s and 2  s is:

Options:
A 32A+4B
B 3A+7B
C 32A+73B
D A2+B3

The correct answer is:
32A+73B

Solution:
V=At+Bt2
X= ∫ 0 t Vdt ⇒ X=At22+Bt33
t=1
X1=A2+B3
t=2
X2=2A+8B3
X2-X1=3A2+7B3

Topic: Physics, Motion In One Dimension, NEET, NEET 2016 (Phase 1)
If the velocity of the electron in Bohr’s first orbit is 2.19 × 106ms–1, calculate the de Broglie wavelength associated with it.

Options:
A 430 pm
B 652 pm
C 332 pm
D 774 pm

The correct answer is:
332 pm

Solution:
Correct Option is : (C)
332 pm

Topic: Chemistry, Structure of Atom, NEET
If the velocity v of a particle moving along a straight line decreases linearly with its displacement S is 20 m s-1 to a value approaching to zero at S= 30 m, then the acceleration of the particle at S=15 m, is

Options:
A 2 3 m s −2
B − 2 3 m s −2
C 20 3 m s −2
D â 20 3 m s â2

The correct answer is:
â 20 3 m s â2

Solution:
Slope of line = - 2 3
Equation of line is v - 2 0 = - 2 3 S - 0
â V = 2 0 - 2 3 S â¦ i
Velocity at S = 15 m,
i.e.,v=20-2315=10 m s-1
a=vdvds=vÃslope
a=10-23
=â 20 3 m s â2

Topic: Physics, Motion In One Dimension, NEET
If the vertical component of earth's magnetic field at a place is 3 times the horizontal component, then the value of dip at that place is

Options:
A 60°
B 45°
C 30°
D 15°

The correct answer is:
60°

Solution:
Here, BV=3 BH
We know that, angle of dip, Î¸=tan-1â¡BVBH
âÎ¸=tan-1â¡3 BHBH=tan-1â¡3=60Â°
â´ Angle of dip, Î¸=60Â°

Topic: Physics, Magnetic Properties of Matter, NEET
If the voltage across 500 Î© is 5 V. Then R2 is

Options:
A 400Â Î©
B 200Â Î©
C 300 Î©
D 500Â Î©

The correct answer is:
300 Î©

Solution:
Current through R4 (as well as R3) is i1=VR=5500=10 mA
Potential drop across 400 Ω is
V400=18-10×10-3×600
=12 V
Current through battery,
I=12400=30 mA
∴ Current through R2, i2=30-10=20 mA
∴R2=620×10-3=300 Ω

Topic: Physics, Current Electricity, NEET
If the volume of the vessel in which the reaction 2NO+O2→2NO2 is occurring is diminished to 1/3 rd of its initial volume. The rate of the reaction will be increased by

Options:
A 5 times
B 8 times
C 27 times
D 35 times

The correct answer is:
27 times

Solution:
For a given reaction 2NOg+O2g⇌2NO2g
Rate of reaction =k[NO]2[O2]
Rate of reaction is directly proportional to concentration of the compound or inversely proportional to the volume of the vessel.
i.e.,
C∝nV
If volume of vessel is reduced by 1/3 rd of its initial value, then concentration of compound is increased by 3 times and consequently the rate of reaction increases by 27 times.

Topic: Chemistry, Chemical Kinetics, NEET
If the wavelength of light coming from a distant galaxy is found to be 0.5% more than that coming from a source on earth. Then the velocity of the galaxy will be

Options:
A 3×1010 m s-1
B 1.5×1010 m s-1
C 1.5×108 m s-1
D 1.5×106 m s-1

The correct answer is:
1.5×106 m s-1

Solution:
dλλ=+0.5%=0.5100
dλλ=ac or a=cdλλ
=3×108×0.5100=1.5×106 m s-1

Topic: Physics, Wave Optics, NEET
If the wavelength of light used is 6000 â«. The angular resolution of telescope of objective lens having diameter 10 cm is ______ rad.

Options:
A 7.55×10-6
B 6.10×10-6
C 6.55×10-6
D 7.32×10-6

The correct answer is:
7.32×10-6

Solution:
Limit of resolution sin⁡θ=θ=1.22λD
Putting values we get option 7.32×10-6

Topic: Physics, Wave Optics, NEET
If the wavelength of maximum intensity of radiation emitted by sun and moon are 0.5Ã10-6 m and 10-4 m respectively, the ratio of their temperature is

Options:
A 1 : 100
B 1 : 200
C 200 : 1
D 400 : 1

The correct answer is:
200 : 1

Solution:
T1T2=n=λm2λm1= 10-40.5×10-6=200

Topic: Physics, Thermal Properties of Matter, NEET
If the work done in blowing a bubble of volume V is W, then the work done in blowing the bubble of volume 2V from the same soap solution will be

Options:
A W
B 2 W
C 2 3 W
D 4 3 W

The correct answer is:
4 3 W

Solution:
As volume of the bubble
v= 4 3 π R 3 ⇒ R = 3 4 π 1 / 3 V 1 / 3 ⇒ R 2 = 3 4 π 2 / 4 V 2 / 3
⇒ R 2 α V 2 / 3
Work done in blowing a soap bubble
W = 8 π R 2 T ⇒ W ∝ R 2 ∝ V 2 / 3
∴ W 2 W 1 = V 2 V 1 2 / 3 = 2 V V 2 / 3 = 2 2 / 3 = 4 1 / 3 ⇒ W 2 = 4 3 W

Topic: Physics, Mechanical Properties of Fluids, NEET
If the work function for a certain metal is 3.2Ã10-19 J and it is illuminated with light of frequency Î½=8Ã1014 Hz, the maximum kinetic energy of the photoelectron would be

Options:
A 2.1Ã10-19 J
B 3.2Ã10-19 J
C 5.3Ã10-19 J
D 8.5Ã10-19 J

The correct answer is:
2.1Ã10-19 J

Solution:
Maximum KE =hv-Ï0
=6.63Ã10-34Ã8Ã1014-3.2Ã10-19
=2.1Ã10-19 J

Topic: Physics, Dual Nature of Matter, NEET
If there are 99 bases in an mRNA that codes for a protein with 33 amino acids and the base at position 30 undergo nonsense mutation, then what will be the length of polypeptide formed?

Options:
A 11 amino acid long
B 30 amino acid long
C 9 amino acid long
D 29 amino acid long

The correct answer is:
9 amino acid long

Solution:
99 bases long mRNA chain can specify 33 amino acid, if nonsense mutation occurs and 30 position than 10th codon becomes stop codon, as a results the new mRNA can code for a protein with only 9 amino acid as the 10th codon becomes stop codon.

Topic: Biology, Molecular Basis of Inheritance, NEET
If there are 250 snails in a pond, and within a year their number increases to 2500 by reproduction. What should be their birth rate per snail per year?

Options:
A $25$
B $15$
C $10$
D $9$

The correct answer is:
$9$

Solution:
Birth rate $=\frac{\Delta \mathrm{N}}{\mathrm{N} \Delta \mathrm{t}}$
Here, $\quad N=250$
$\Delta t=1$ year
$\Delta N=2500-250$
$=2250$
Birth rate $=\frac{2250}{250 \times 1}$
$=9$

Topic: Biology, Organisms and Populations, NEET, NEET 2023 (Manipur)
If there are 999 bases in an RNA that codes for a protein with 333 amino acids, and the base at position 901 is deleted such that the length of the RNA becomes 998 bases, how many codons will be altered?

Options:
A 1
B 11
C 33
D 333

The correct answer is:
33

Solution:
33 codons will be altered if the 901st base is deleted and RNA has only 998 bases instead of 999 bases
Total bases present in RNA = 999
Bases left after deletion of 901st base
In RNA = 999 - 901 = 98
3 codon= 1 amino acid
Therefore 98/3= approx 33
A number of codons present in 98 bases= 33 (Approximately as three codons code for one amino acid).

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2017
If there are no heat losses, the heat released by the condensation of x gram of steam at 100Â°C into the water at 100Â°C can be used to convert y gram of ice at 0Â°C into the water at 100Â°C. Then the ratio of y:x is nearly

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

The correct answer is:
3:1

Solution:
y×80+y×1×100=x×540
⇒180y=540x
⇒ yx=3
⇒ y:x=3:1

Topic: Physics, Thermal Properties of Matter, NEET
If there is a major deficiency of antibodies in a person to which of the following can be analysed?

Options:
A Serum globulins
B Fibrinogen in the plasma
C Haemocytes
D Serum albumins

The correct answer is:
Serum globulins

Solution:
Serum globulins → It makes 2 to 3% of plasma proteins. The α and β -globulin sent with the hormones to transport them the γ -globulin form antibodies.

Topic: Biology, Human Health and Diseases, NEET
If there is no greenhouse effect, then the average temperature of the earth will be

Options:
A -18oC
B 0oC
C -10oC
D 15oC

The correct answer is:
-18oC

Solution:
The greenhouse effect is beneficial for life on Earth. If there were no greenhouse effect, the Earth's average surface temperature would be very chilly, -18°C (0°F) instead of 15°C (59°F).

Topic: Biology, Environmental Issues, NEET
If there is no rotation of plane light by a compound in a specific solvent, though to be chiral, it may mean that:

Options:
A the compound is certainly meso
B there is no compound in the solvent
C the compound may be a racemic mixture
D the compound is certainly a chiral

The correct answer is:
the compound is certainly meso

Solution:
Meso compound like meso tartaric acid is optically inactive due to the presence of planar molecular symmetry.
Related Theory
Meso compounds are molecules having multiple stereocenters, but their mirror images are superimposable. Meso compounds have an identical mirror image whereas enantiomers have a non-superimposable mirror image.

Topic: Chemistry, General Organic Chemistry, NEET, NEET 2007
If there is no rotation of plane polarised light by a compound in a specific solvent, though it is chiral, it may mean that

Options:
A the compound is certainly meso
B there is no compound in the solvent
C the compound may be a racemic mixture
D the compound is certainly a chiral

The correct answer is:
the compound is certainly meso

Solution:
Meso compound does not rotate plane polarised light. Compound which contains tetrahedral atoms with four different groups but the whole molecule is achiral, is known as meso compound. It possesses a plane of symmetry and is optical inactive. One of the asymmetric carbon atoms turns the plane of polarised light to the right and other to the left and to the same extent so that the rotation due to upper half is compensated by the lower half, i.e., internally compensated, and finally there is no rotation of plane polarised light.

Topic: Chemistry, General Organic Chemistry, NEET
If there is zero absorption in the polaroid and if the intensity of plane-polarized light coming out of polaroid is A2, then the intensity of the incident beam will be

Options:
A A2
B A22
C 2A2
D None of these

The correct answer is:
2A2

Solution:
Due to polarization, intensity of unpolarised light will reduce to half of its value.

Topic: Physics, Wave Optics, NEET
If three unit vectors are inclined at an angle of 60Â° with each other, then the magnitude of their resultant vector will be

Options:
A zero
B 6
C 3
D 9

The correct answer is:
6

Solution:
We assume a^+b^+c^=R→
R→⋅R→=a^+b^+c^⋅a^+b^+c^
R2=1+1+1+cos⁡60+cos⁡60+cos⁡60+cos⁡60+cos⁡60+cos⁡60
R2=6
R=6

Topic: Physics, Mathematics in Physics, NEET
If T.S. of young dicot stem is stained with Iodine solution, which of the following region will be stained dark blue?

Options:
A Cortex
B Pericycle
C Endodermis
D Cambium

The correct answer is:
Endodermis

Solution:
Iodine solution is used to stain starch. In dicot stem, the innermost layer of the cortex is called the endodermis. The cells of the endodermis are rich in starch grains and the layer is also referred to as the starch sheath. Thus staining gives blue black colour due to starch.

Topic: Biology, Anatomy of Flowering Plants, NEET
If two compounds have the same empirical formula but different molecular formula, then they must have

Options:
A Same viscosity
B Different percentage composition
C Different molecular weight
D Same vapour density

The correct answer is:
Different molecular weight

Solution:
If molecular formula is different than molecular weight is also different.

Topic: Chemistry, General Organic Chemistry, NEET
If two genes show 50 % recombination frequency, then which of the following statement is not correct about it?

Options:
A The genes may be on different chromosomes.
B The genes are tightly linked.
C The genes show independent assortment.
D The genes are present on the same chromosome, they undergo crossing over in meiosis.

The correct answer is:
The genes are tightly linked.

Solution:
If two genes show 50 % recombination frequency then the genes are widely located on the chromosome and are loosely linked, thus chances of their separation during crossing over is more. Distance between two genes determines strength of linkage and frequency of crossing over.

Topic: Biology, Principles of Inheritance and Variation, NEET
If two measurements are close to each other but not accurate, what term describes them?

Options:
A Precise
B Accurate
C Consistent
D Significant

The correct answer is:
Precise

Solution:
Two measurements that are close to each other but not accurate are described as precise.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
If two mirrors are inclined at some angle and an object is placed between the mirrors and there are 7 images formed for an object, then the angle between the mirrors is

Options:
A 54°
B 45°
C 60°
D 64°

The correct answer is:
45°

Solution:
n=360°θ-1=7
⇒360°θ=8
θ=45°

Topic: Physics, Ray Optics, NEET
If two mirrors are kept at 60o to each other, then the number of images formed by them is

Options:
A 5
B 6
C 7
D 8

The correct answer is:
5

Solution:
n = 360 o θ o - 1 = 360 0 60 o - 1 = 5 .

Topic: Physics, Ray Optics, NEET
If two molecules of A and B having mass 100 amu and 64 amu respectively and rate of diffusion of A is 12Ã10-3, then what will be the rate of diffusion of B?

Options:
A 15×10-3
B 64×10-3
C 5×10-3
D 46×10-3

The correct answer is:
15×10-3

Solution:
According to Graham's law of diffusion
Rate of diffusion râ1d
Molecular weight M=2Ãvapour density
r1r2=V.D2V.D1
MA=1002
MB=642
rA=12Ã10-3 and rB=?
rArB=dBdA=V.DBV.DA
12Ã10-3rB=64/2100/2=64100=810
rB=12Ã10-3Ã108
=15Ã10-3

Topic: Chemistry, States of Matter, NEET
If two persons with 'AB' blood group marry and have sufficiently large number of children, these children could be classified as 'A' blood group : 'AB' blood group : 'B' blood group in $1: 2: 1$ ratio. Modern technique of protein electrophoresis reveals presence of both 'A' and ' $B$ ' type proteins in 'AB' blood group individuals. This is an example of

Options:
A codominance
B incomplete dominance
C partial dominance
D complete dominance

The correct answer is:
codominance

Solution:
In codominance both alleles of a pair express themselves fully in $F_1$ hybrid. It is contrary to the situation seen in incomplete dominance, where traits express themselves only partially. This is not the example of partial dominance or complete dominance

Topic: Biology, Principles of Inheritance and Variation, NEET, NEET 2013 (All India)
If two rods of length L and 2L having coefficients of linear expansion Î± and 2Î±, respectively, are connected such that total length becomes 3L, the average coefficient of linear expansion of the composition rod equals

Options:
A 32α
B 52α
C 53α
D none of these

The correct answer is:
53α

Solution:
Δl=Δl1+Δl2
αeq3LΔT=αLΔT+2α×2LΔT
3αeq=5α
⇒ αeq=53α

Topic: Physics, Thermal Properties of Matter, NEET
If two tuning forks A and B are sounded together, they produce 4 beats per second. A is then slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256. The frequency of B will be

Options:
A 250
B 252
C 260
D 262

The correct answer is:
252

Solution:
Known frequency, nA=256 Hz
Unknown frequency, nB=?
Beats x=4 bps, which is decreasing after loading (i.e. x decreases)
We also know that the tuning fork A is loaded so nA decreases
Hence nA-nB=x (decreases) ......(i) Correct
nB-nA=x (increases)......(ii) Wrong
nB=nA-x=252 Hz

Topic: Physics, Waves and Sound, NEET
If two wires of same length l and area of the cross-section A with Young modulus Y and 2Y connect in series and one end is fixed on roof and another end with mass m make simple harmonic motion, then the time period is

Options:
A 2πmlYA
B 2πml3YA
C 2π3ml2YA
D 2πml2YA

The correct answer is:
2π3ml2YA

Solution:
The force constant of wires are
k1=YAl, k2=2YAl
In series k=k1k2k1+k2=23YAl
T=2π3ml2YA

Topic: Physics, Oscillations, NEET