datavorous/entrance-exam-dataset huggingface dataset:
If N0 is the initial mass of a substance with half-life t12=5 years, then the amount of substance left after 15 years is

Options:
A N08
B N016
C N02
D N04

The correct answer is:
N08

Solution:
N0 is the initial amount of substance and N is the amount left after decay.
Thus, N = N 0 1 2 n
n = no. of half lives = tt1/2 = 1 5 5 = 3
Therefore, N = N 0 1 2 3 = N 0 8

Topic: Physics, Nuclear Physics, NEET
If N2gas is bubbled through water at 293 K, how many millimoles of N2gas would dissolve in 1 litre of water? Assume that N2exerts a partial pressure of 0.987 bar. Given that Henry’s law constant for N2at 293 K is 76.48 kbar.

Options:
A 0.716 mmol
B 0.234 mmol
C 0.435 mmol
D 0.876 mmol

The correct answer is:
0.716 mmol

Solution:
Correct Option is : (A)
0.716 mmol

Topic: Chemistry, Solutions, NEET
If $n=6$, the correct sequence for filling of electrons will be

Options:
A $n s \longrightarrow(n-1) d \longrightarrow(n-2) f \longrightarrow n p$
B $n s \longrightarrow(n-2) f \longrightarrow n p \longrightarrow(n-1) d$
C $n s \longrightarrow n p \longrightarrow(n-1) d \longrightarrow(n-2) f$
D $n s \longrightarrow(n-2) f \longrightarrow(n-1) d \longrightarrow n p$

The correct answer is:
$n s \longrightarrow(n-2) f \longrightarrow(n-1) d \longrightarrow n p$

Solution:
$6 s \rightarrow 4 f \rightarrow 5 d \rightarrow 6 p$ for $n=6$

Topic: Chemistry, d and f Block Elements, NEET, NEET 2011 (Screening)
If n = 6, the correct sequence for filling of electrons will be

Options:
A nsân-2 fân-1 dânp
B nsân-1 dân-2 fânp
C nsân-2 fânpân-1d
D nsânp n-1 dân-2 f

The correct answer is:
nsân-2 fân-1 dânp

Solution:
If n = 6, the correct sequence for filling of electrons will be nsân-2 fân-1 dânp n=6.
During filling of electrons Hund's rule, Aufbau principle and Pauli's Exclusion principle must be followed.

Topic: Chemistry, Structure of Atom, NEET
If Na+ ion is larger than Mg2+ ion and S2-is larger than Cl- ion, which of the following will be least soluble in water?

Options:
A Sodium chloride
B Sodium sulphide
C Magnesium chloride
D Magnesium sulphide

The correct answer is:
Magnesium sulphide

Solution:
Higher the lattice energy lower the solubility. Out of the four combinations possible, the lattice energy of MgS (bi-bivalent ionic solid) is higher than those of Na2S, MgCl2 (uni-bivalent or biuni-valent ionic solids ) and NaCl (univalent ionic solids) and hence, MgS is the least soluble. Thus, due to higher charge/ion, the lattice formed between Mg2+ and S2- is very strong.
As lattice energy overweighs the hydration energy here, the salt is least soluble.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
If n, e, Ï and m represent electron density, charge, relaxation time and mass of an electron respectively, then the resistance of a wire of length l and cross-sectional area A is

Options:
A mlne2ÏA
B mτAne2l
C ne2τAml
D ne2mlτA

The correct answer is:
mlne2τA

Solution:
R=ÏlA

Since we know resistivity is given by Ï=mne2r

Resistance R=mlne2ÏA

where,
m= Mass of electron
l= length of conductor
n= charge density
e= charge of electron
Ï= relaxation time
A= cross-sectional area

Topic: Physics, Current Electricity, NEET
If Nx is the number of electrons in bonding molecular orbitals of an atom and Ny is the number of electrons in antibonding molecular orbitals, then the molecule/atom will be stable if

Options:
A Nx<Ny
B Nx=Ny
C Nx>Ny
D Nx≤Ny

The correct answer is:
Nx>Ny

Solution:
Stability of molecule/ions depends on number of electrons in bonding and antibonding molecular orbitals.
Electrons in bonding molecular orbitals>electrons in antibonding molecular orbitals

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
If NaCl is doped with 10-4 mol% of SrCl2, the concentration of cation vacancies will be (NA=6.02×1023mol-1)

Options:
A 6.02×1016mol-1
B 6.02×1017mol-1
C 6.02×1014mol-1
D 6.02×1015mol-1

The correct answer is:
6.02×1017mol-1

Solution:
As each Sr2+ ion introduces one cation vacancy, therefore, concentration of cation vacancies = mole% of SrCl2 added.
So concentration of cation vacancies
=10-4mole%=10-4100×6.023×1023×1=6.023×1017

Topic: Chemistry, Solid State, NEET
If $\mathrm{NaCl}$ is doped with $10^{-4} \mathrm{~mol} \%$ of $\mathrm{SrCl}_2$, the concentration of cation vacancies will be: $\left(\mathrm{N}_A=6.02 \times 10^{23} \mathrm{~mol}^{-1}\right)$

Options:
A $6.02 \times 10^{16} \mathrm{~mol}^{-1}$
B $6.02 \times 10^{17} \mathrm{~mol}^{-1}$
C $6.02 \times 10^{14} \mathrm{~mol}^{-1}$
D $6.02 \times 10^{15} \mathrm{~mol}^{-1}$

The correct answer is:
$6.02 \times 10^{17} \mathrm{~mol}^{-1}$

Solution:
Since each $\mathrm{Sr}^{++}$ion provides one cation vacancy, hence Concentration of cation vacancies $=$ mole $\%$ of $\mathrm{SrCl}_2$ added
$\begin{aligned}
& =10^{-4} \text { mole } \% \\
& =\frac{10^{-4}}{100} \times 6.023 \times 10^{23} \\
& =6.023 \times 10^{17} \mathrm{~mol}^{-1}
\end{aligned}$
Related Theory
Doping is the process of adding impurities to intrinsic semiconductors to alter their properties. When an intrinsic semiconductor is doped with Trivalent impurity it becomes a P-Type semiconductor. The $P$ stands for Positive, which means the semiconductor is rich in holes or Positive charged ions.

Topic: Chemistry, Solid State, NEET, NEET 2007
If neural signals are sent through the parasympathetic nerves of the ANS, the heart rate will

Options:
A decrease
B increase
C show no change
D first decrease then increase

The correct answer is:
decrease

Solution:
Normal activities of the heart are regulated intrinsically, i.e., auto regulated by specialised muscles (nodal tissue), hence the heart is called myogenic. A special neural centre in the medulla oblongata can moderate the cardiac function through the autonomic nervous system (ANS). Neural signals through the sympathetic nerves (part of ANS) can increase the rate of heartbeat, the strength of ventricular contraction and thereby the cardiac output. On the other hand, parasympathetic neural signals (another component of ANS) decrease the rate of heartbeat, speed of conduction of action potential and thereby the cardiac output.

Topic: Biology, Body Fluids and Circulation, NEET
If on transition to the ground state an He+ ion emits two photons in succession, having wavelengths 1026.7 A∘ and 304 A∘, then the quantum number n corresponding to the exciting state of He+ ion is [R=1.096×107 m-1]

Options:
A 4
B 6
C 2
D 1

The correct answer is:
6

Solution:
hcλ1+hcλ2=RchZ2112-1n2
Put λ1=1026.7Å and λ2=304 Å
Z=2 for He+ ion
On solving for n
n=6

Topic: Physics, Atomic Physics, NEET
If one mole of KCl in one kg of water increases the boiling point by 1.04 K, what is the degree of dissociation for KCl?

Options:
A 0.5
B 1.0
C 2.0
D 3.0

The correct answer is:
0.5

Solution:
The paragraph provides an example where one mole of KCl in one kg of water increases the boiling point by 1.04 K. From this information, you can calculate that the degree of dissociation is 0.5.

Topic: Chemistry, Solutions, NEET
If one sphere collides head-on with another sphere of the same mass at rest inelastically. The ratio of their speeds v2v1 after collision shall be

Options:
A 1-e1+e
B 2e1+e
C 1+e1-e
D e

The correct answer is:
1+e1-e

Solution:
v1=m-emu+02m
v2=0+mu1+e2m
â´ v1v2=1-e1+e ......... C
v2v1=1+e1-e

Topic: Physics, Center of Mass Momentum and Collision, NEET
If one strand of DNA has a nucleotide sequence 3' ATTCGCTAT 5', the nucleotide sequence of other DNA strand will be

Options:
A 3’ TAAGCGATA 5’
B 5’ TAGCACGTA 5’
C 5’ TAGCACGTA 3’
D 5â TAAGCGATA 3â

The correct answer is:
5’ TAAGCGATA 3’

Solution:
In a double-stranded DNA, the sequence of nucleotides is complementary to each other, i.e., A pairs with T and G pairs with C. Hence, the sequence of nucleotide for 3' ATTCGCTAT 5' will be 5' TAAGCGATA 3'.

Topic: Chemistry, Biomolecules, NEET
If one strand of DNA has the nitrogenous base sequence as ATCTG, what would be the complementary RNA strand sequence?

Options:
A TTAGU
B UAGAC
C AACTG
D ATCGU

The correct answer is:
UAGAC

Solution:
If one strand of DNA has the nitrogenous base sequence as ATCTG, the complementary sequence of mRNA will be UAGAC.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2012 (Screening)
If one strand of DNA has the sequence ATCGTATG, the sequence in the complementary strand would be

Options:
A TAGCTTAC
B TCACATAC
C TAGCATAC
D TACGATAC

The correct answer is:
TAGCATAC

Solution:
Because of size and geometries of the bases, the only possible pairings in DNA are between G (guanine) and C (cytosine) through three H-bonds and between A (adenine) and T (thymine) through two H-bonds. Hence,

Topic: Chemistry, Biomolecules, NEET
If one strand of DNA has the sequence ATGCTTGA, the sequence in the complimentary strand would be

Options:
A TCCGAACT
B TACGTAGT
C TACGAATC
D TACGAACT

The correct answer is:
TACGAACT

Solution:
In a DNA molecule, A=T,C≡G.
So, the complementary sequence of ATGCTTGA is TACGAACT.

Topic: Chemistry, Biomolecules, NEET
If only one hundredth part of total current flowing in the circuit is to be passed through a galvanometer of resistance G, then the value of shunt resistance required will be -

Options:
A G10
B G100
C G99
D G999

The correct answer is:
G99

Solution:
Using Kirchoff's Loop law
igG=i-igS
i100G=i-i100S
G100=99S100
S=G99

Topic: Physics, Current Electricity, NEET
If p is the pressure, V the volume, R the gas constant, k the Boltzmann's constant and T the absolute temperature, then the number of molecules in the given mass of the gas is given by

Options:
A pVRT
B pVkT
C pRT
D pV

The correct answer is:
pVkT

Solution:
In a given mass of the gas
m=pVkT
k being Boltzmann's constant.

Topic: Physics, Thermodynamics, NEET
If pKb for fluoride ion at 25 ° C is 10.83, the ionization constant of hydrofluoric acid in water at this temperature is

Options:
A 1.74×10-5
B 3.52×10-3
C 6.75×10-4
D 5.38×10-2

The correct answer is:
6.75×10-4

Solution:
pKb=10.83

âlog Kb=10.83

Kb=antilog(â10.83)

Kb=1.48Ã10-11

KaÃKb=Kw
So Ka=KwKb
=10-141.48Ã10-11
=6.75Ã10-4

Topic: Chemistry, Ionic Equilibrium, NEET
If pKb for the fluoride ion at 25° C is 10.83, the ionization constant of hydrofluoric acid in water at this temperature is

Options:
A 1.74×10-5
B 3.52×10-3
C 6.76×10-4
D 5.38×10-2

The correct answer is:
6.76×10-4

Solution:
pKb=10.83,
log  K b =−10.83−(11−0.17)
On taking antilog
Kb=1.479Ã10-11
Ka.Kb=Kw
or KaÃ1.479Ã10-11=1.0Ã10-14
Ka=6.76Ã10-4

Topic: Chemistry, Ionic Equilibrium, NEET
If parasitism is an example of +ve, - ve interaction, then competition is an example of

Options:
A -ve, -ve interaction
B -ve, O interaction
C +ve, -ve interaction
D +ve, +ve interaction

The correct answer is:
-ve, -ve interaction

Solution:
Interactions of populations of two different species are termed interspecific interactions. These can be detrimental, beneficial or neutral to the involved species. If symbols are given to denote detrimental effect, beneficial effect and neutral effect as '-', '+' and '0'.
Parasitism is a type of interaction between a parasite and host where only parasite benefits from the relationship but it is detrimental to the host. Thus, parasitism will be' +', '-'
Competition is a type of interaction where the interacting species compete for the same resource and such interaction do not benefit either of the groups involved as resources are limited and it puts a stress on the population. Hence, competition is ‘–‘ ’-‘.

Topic: Biology, Organisms and Populations, NEET
If particles are moving with the same velocity, then the de Broglie wavelength is maximum for:

Options:
A proton
B $\alpha$-particle
C neutron
D $\beta$-particle

The correct answer is:
$\beta$-particle

Solution:
De-Bronglie wavelength is maximum for $\beta$-particle.

Topic: Physics, Dual Nature of Matter, NEET, NEET 2002
If pBR322 cloning vector is cut by Pvu I enzyme for the formation of rDNA then which of its marker gene helps in the selection of recombinants?

Options:
A ampR gene
B tetR gene
C gal gene
D Both (A) and (B)

The correct answer is:
Both (A) and (B)

Solution:
pBR 322 has two selectable markers which are amphicillin and tertacyclin resistant genes. Amphicilin resistant gene has two restriction enzyme recognition site, Pvu I and Pst I. If the vector is cut by Pvu I enzyme for formation of rDNA than amphicillin resistant gene becomes inactive due to insertional inactivation.

Topic: Biology, Biotechnology - Principles and Processes, NEET
If pH of a saturated solution of Ba(OH)2 is 12, the value of its K(sp) is

Options:
A 5.00×10-7M3
B 4.00×10-6M3
C 4.00×10-7M3
D 5.00×10-6M3

The correct answer is:
5.00×10-7M3

Solution:
As pH=12
pOH=14-12=2
[OH-]=10-2M=0.01M
In case of Ba(OH)2s⇌Ba+2s+2OH-22s
As 2s=0.01mole/L
s=0.012=5×10-3mole/L
Ksp for Ba(OH)2=4s3=4(5×10-3)3=5×10-7M3

Topic: Chemistry, Chemical Equilibrium, NEET
If $\mathrm{pH}$ of a saturated solution of $\mathrm{Ba}(\mathrm{OH})_2$ is 12 , the value of its $K_{s p}$ is

Options:
A $4.00 \times 10^{-6} \mathrm{M}^3$
B $4.00 \times 10^{-7} \mathrm{M}^3$
C $5.00 \times 10^{-6} \mathrm{M}^3$
D $5.00 \times 10^{-7} \mathrm{M}^3$

The correct answer is:
$5.00 \times 10^{-7} \mathrm{M}^3$

Solution:
Given, $\mathrm{pH}$ of $\mathrm{Ba}(\mathrm{OH})_2=12$
$$
\begin{aligned}
\therefore \quad\left[\mathrm{H}^{+}\right] & =\left[1 \times 10^{-12}\right] \\
\text { and }\left[\mathrm{OH}^{-}\right] & =\frac{1 \times 10^{-14}}{1 \times 10^{-12}}\left[\because\left[\mathrm{H}^{+}\right]\left[\mathrm{OH}^{-}\right]=1 \times 10^{-14}\right]
\end{aligned}
$$
$$
\begin{aligned}
&=1 \times 10^{-2} \mathrm{~mol} / \mathrm{L} \\
& \mathrm{Ba}(\mathrm{OH})_2 \longrightarrow \mathrm{Ba}^{2+}+2 \mathrm{OH}^{-} \\
& \mathrm{K}_{\mathrm{sp}}=\left[\mathrm{Ba}^{2+}\right]\left[\mathrm{OH}^{-}\right]^2 \\
&=[\mathrm{s}][2 \mathrm{~s}]^2 \\
&=\left[\frac{1 \times 10^{-2}}{2}\right]\left(1 \times 10^{-2}\right)^2 \\
&=0.5 \times 10^{-6}=5.0 \times 10^{-7} \mathrm{M}^3
\end{aligned}
$$

Topic: Chemistry, Ionic Equilibrium, NEET, NEET 2010 (Screening)
If pKa=4 and K a = CÎ± 2, then find van't Hoff factor for a weak HA type acid, when C=0.01 M.

Options:
A 1.01
B 1.02
C 1.10
D 1.20

The correct answer is:
1.10

Solution:
K a = Cα 2

10 −4 = 10 −2 × α 2

α=0.1

i=1+α=1.1

Topic: Chemistry, Solutions, NEET
If potential(in volts) in a region is expressed as Vx,y,z=6xy-y+2yz, the electric field(in N C-1) at point1,1,0 is

Options:
A -6i^+5j^+2k^.
B -2i^+3j^+k^.
C -6i^+9j^+k^.
D -3i^+5j^+3k^.

The correct answer is:
-6i^+5j^+2k^.

Solution:
V=6xy-y+2yz
E→=-∂V∂xi^+∂V∂yj^∂V∂zk^
E→=-6yi^+6x-1+2zj^+(2y)k^
E→(1, 1, 0)=-6i^+5j^+2k^

Topic: Physics, Electrostatics, NEET, NEET 2015 (Phase 2)
If power dissipated in the $9 \Omega$ resistor in the circuit shown is $36 \mathrm{~W}$, the potential difference across the $2 \Omega$ resistor is

Options:
A $8 \mathrm{~V}$
B $10 \mathrm{~V}$
C $2 \mathrm{~V}$
D $4 \mathrm{~V}$

The correct answer is:
$10 \mathrm{~V}$

Solution:
Electric power, $P=i^2 R$
$\therefore$ Current, $\quad i=\sqrt{\frac{P}{R}}$
For resistance of $9 \Omega$
$$
i_1=\sqrt{\frac{36}{9}}=\sqrt{4}=2 \mathrm{~A}
$$
$$
\begin{aligned}
i_2 & =\frac{i_1 \times R}{6}=\frac{2 \times 9}{6}=3 \mathrm{~A} \\
i & =i_1+i_2=2+3=5 \mathrm{~A} \\
V_2 & =I R_2=5 \times 2=10 \mathrm{~V}
\end{aligned}
$$

Topic: Physics, Current Electricity, NEET, NEET 2011 (Screening)
If pressure at half the depth of a lake is equal to 2/3 pressure at the bottom of the lake then what is the depth of the lake?

Options:
A 10 m
B 20 m
C 60 m
D 30 m

The correct answer is:
20 m

Solution:
Pressure at bottom of the lake = P 0 + h ρ g
and pressure at half the depth of a lake
= P 0 + h 2 ρ g
According to given condition
= P 0 + 1 2 ρ g = 2 3 ρ 0 + h ρ g
⇒ h = 2 P 0 ρ g = 2 × 1 0 5 1 0 3 × 1 0 = 2 0 m

Topic: Physics, Mechanical Properties of Fluids, NEET
If producer is a large tree that supports a number of herbivorous animals which are further attacked by ectoparasites, the pyramid of number shall be

Options:
A Inverted
B Upright
C Irregular
D Spindle shaped

The correct answer is:
Inverted

Solution:
The pyramid of numbers depicts the relationship in terms of the number of producers, herbivores and the carnivores at their successive trophic levels. There is a decrease in the number of individuals from the lower to the higher trophic levels. The number pyramid varies from ecosystem to ecosystem.
The given condition shows a parasitic food chain where one primary producer supports numerous parasites which support more hyperparasites. Hence the pyramid of number would be inverted.

Topic: Biology, Ecosystem, NEET
If proton and Î± - particle are accelerated by the same potential V. Then, the ratio of their wavelengths Î»P:Î»Î± would be

Options:
A 22:1
B 1 : 2 2
C 2 : 1

D 1 : 2

The correct answer is:
22:1

Solution:
KE of proton and alpha-particle shall be 1 eV and 2 eV respectively.
Now, momentum, p = 2 mKE
∴ The momentum of proton is pP=2mp×eV
∴ The momentum of α-particle whose mass
m α = 4 m P is
pα=8mp×2eV=16mpeV
∴ Now, λ = h p [de-Broglie relation]
⇒λpλα=pαpp=16mpeV2mpeV=22:1

Topic: Physics, Atomic Physics, NEET
If $Q, E$ and $W$ denote respectively the heat added, change in internal energy and the work done in a closed cycle process, then

Options:
A $W=0$
B $Q=W=0$
C $E=0$
D $Q=0$

The correct answer is:
$E=0$

Solution:
Key Idea : In a cyclic process, system is not isolated from the surroundings.
In a cyclic process, a system starts from one point and ends at the same point. In this case, the change in the internal energy must again be zero and therefore the thermal energy added to
the system must equal the work done during the cycle. That is, in a cyclic process.
$$
\Delta U=0 \text { or } E=0
$$

Topic: Physics, Thermodynamics, NEET, NEET 2008 (Screening)
If R1 and R2 are the resistances of the filaments of 200 W and 100 W electric bulbs operated at 220 V, then R1R2 is

Options:
A 2
B 0.5
C 4
D 0.25

The correct answer is:
0.5

Solution:
Power of bulb, P=V2R
â´ P2P1=R1R2
Or R1R2=100200=0.5

Topic: Physics, Current Electricity, NEET
If ∆r1 represents the difference in radii of stationary orbits for n=3 and n=4 in a hydrogen atom and ∆r2 represents the difference in radii of stationary orbits for n=8 and n=9, then the value of ∆r1∆r2 is

Options:
A 0.71
B 0.41
C 2.43
D 14.82

The correct answer is:
0.41

Solution:
Use the relationship between the radius of an orbit and quantum number n of that orbit.
r4-r3r9-r8=r1×42-r1×32r1×92-r1×82=16-981-64=0.41

Topic: Physics, Atomic Physics, NEET
If $R$ is the radius of the earth and $g$ is the acceleration due to gravity on the earth surface. Then the mean density of the earth will be

Options:
A $\frac{3 g}{4 \pi R G}$
B $\frac{4 \pi G}{3 g R}$
C $\frac{\pi R G}{12 g}$
D $\frac{3 \pi R}{4 g G}$

The correct answer is:
$\frac{3 g}{4 \pi R G}$

Solution:
Acceleration due to gravity on the earth surface $g=\frac{G M}{R^2}$
$\begin{aligned} & \frac{g=G \frac{4}{3} \pi R^3 \rho}{R^2} \\ & g=G \frac{4}{3} \pi R \rho \\ & \Rightarrow \rho=\frac{3 g}{4 G \pi R}\end{aligned}$

Topic: Physics, Gravitation, NEET, NEET 2023 (Manipur)
If rn is the radius of nth orbit of hydrogen atom, then the relative change in the radius, when an electron jumps from nth orbit to n-1th orbit is nâ«1

Options:
A Directly proportional to n
B Inversely proportional to n
C Inversely proportional to n2
D Independent of n

The correct answer is:
Inversely proportional to n

Solution:
rn∝n2
Δrnrn=2n

Topic: Physics, Atomic Physics, NEET
If radioactive thymidine is used during S-phase of interphase, which part of the chromosome will become radioactive?

Options:
A Near the centromere
B At both end of chromosome
C Euchromatin region
D Both euchromatin and heterochromatin region

The correct answer is:
Both euchromatin and heterochromatin region

Solution:
The replication of genetic material during cell division takes place in S-phase. The complete genetic material is replication thus euchromatin as well as heterochromatin both are replicated. Though euchromatin replicates in early S-phase while
heterochromatin replicates in late S-phase.

Topic: Biology, Cell Cycle and Cell Division, NEET
If radius of second Bohr orbit of the He+ ion is 105.8 pm, what is the radius of third Bohr orbit of Li2+ ion?

Options:
A 15.87 pm
B 1.587 pm
C 158.7 Å
D 158.7 pm

The correct answer is:
158.7 pm

Solution:
According to bohr's model, radius of nth orbit is given by

rn=a0n2Zrn=52.9n2Zin pma0=52.9pm

r1r2=rHe+rLi2+r1r2=n12n22Z2Z1 =223232=23r1r2=rHe+rLi2+=23rHe+ of second orbit=105.8pmrLi2+ of third orbit=105.8 x 32=158.7pm

Topic: Chemistry, Structure of Atom, NEET, NEET 2022 (Phase 1)
If radius of the A1327l nucleus is taken to be RAl then the radius of Te53125 nucleus is nearly

Options:
A 531313 RAl
B 53RAl
C 35RAl
D 135313 RAl

The correct answer is:
53RAl

Solution:
We know, the radius of the nucleus is R=R0 mass Number13
R=R0A13
RAlRTe=2772513=35
RTe=53RAl

Topic: Physics, Nuclear Physics, NEET, NEET 2015 (Phase 1)
If rDNA is introduced in a gene coding for ampicillin, then

Options:
A The host will become resistant for ampicillin
B The host will loose resistant for ampicillin.
C The host will start producing ampicillin
D The host will start producing tetracycline.

The correct answer is:
The host will loose resistant for ampicillin.

Solution:
The recombinant plasmid will lose ampicillin resistance nature due to the insertion of foreign DNA, and this is known as insertional inactivation, but can still be selected out from non-recombinants by plating the transformants on ampicillin medium.

Topic: Biology, Biotechnology - Principles and Processes, NEET
If resistance R=100 Î©, inductance L=2Ï H and capacitance C=8Ï Î¼F are connected in series with an AC source of 200 volt and frequency f as shown in the circuit. If the readings of the hot wire voltmeters V1 and V2 are same then which among the following statements is wrong?

Options:
A f=125 Hz
B f=250 Ï Hz
C current through R is 2A
D V1= V2= 1000 volt

The correct answer is:
f=250 Ï Hz

Solution:
V1=V2 âxL=xc

âf=12ÏLC=125 Hz

I0=V0R=200100 (âµx=0 â´ z=R)

=2A

V1=V2=1X=1.(ÏL)=2Ã2ÏÃ125Ã2Ï

V1=V2=1000 volt

Topic: Physics, Alternating Current, NEET
If ∮S E→·dS→=0 over a surface, then:

Options:
A The electric field inside the surface is necessarily uniform.
B The number of flux lines entering the surface must be equal to the number of flux lines leaving it.
C The magnitude of electric field on the surface is constant.
D All the charges must necessarily be inside the surface.

The correct answer is:
The number of flux lines entering the surface must be equal to the number of flux lines leaving it.

Solution:
The electric flux through a surface is the surface integral of the normal component of the electric field E over that surface. As net flux given by,∮S E→·dS→=0, therefore total number of flux lines entering the surface must be equal to the number of flux lines leaving it.

Topic: Physics, Electrostatics, NEET, NEET 2023 (All India)
If S is stress and Y is Young's modulus of the material of a wire, the energy stored in the wire per unit volume is

Options:
A 2S2Y
B S22Y
C 2YS2
D S2Y

The correct answer is:
S22Y

Solution:
Energy stored in the wire =12stressÃstrainÃvolume
and Young′sÂ modulus=StressStrain
â¹ strain=SY
EnergyÂ storedÂ inÂ Â wireVolume=12ÃstressÃstrain
=12SÃSY=S22Y

Topic: Physics, Mechanical Properties of Solids, NEET
If same mass of liquid water and a piece of ice is taken, then why is the density of ice less than that of liquid water?

Options:
A Ice molecules are more tightly packed than liquid water molecules.
B The crystalline structure of ice leaves more empty space compared to the random arrangement in liquid water.
C Ice molecules have higher kinetic energy than liquid water molecules.
D The hydrogen bonds in ice are weaker compared to those in liquid water.

The correct answer is:
The crystalline structure of ice leaves more empty space compared to the random arrangement in liquid water.

Solution:
Correct Option is : (B)
The crystalline structure of ice leaves more empty space compared to the random arrangement in liquid water.

Topic: Chemistry, Hydrogen, NEET