NEET (UG) 2023

The ratio of radius of gyration of a solid sphere of mass $M$ and radius $R$ about its own axis to the radius of gyration of the thin hollow sphere of same mass and radius about its axis is :

The work functions of Caesium (Cs), Potassium ( K ) and Sodium ( Na ) are 2.14 eV , 2.30 eV and 2.75 eV respectively. If incident electromagnetic radiation has an incident energy of 2.20 eV , which of these photosensitive surfaces may emit photoelectrons?

The amount of energy required to form a soap bubble of radius 2 cm from a soap solution is nearly : (surface tension of soap solution $\left.=0.03 \mathrm{~N} \mathrm{~m}^{-1}\right)$

Resistance of a carbon resistor determined from colour codes is $(22000 \pm 5 \%) \Omega$. The colour of third band must be :

In a series $L C R$ circuit, the inductance $L$ is 10 mH , capacitance $C$ is $1 \mu \mathrm{~F}$ and resistance $R$ is $100 \Omega$. The frequency at which resonance occurs is :

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10} \mathrm{~Hz}$ and amplitude $48 \mathrm{Vm}^{-1}$. Then the amplitude of oscillating magnetic field is : (Speed of light in free space $=3 \times 10^{8} \mathrm{~m} \mathrm{~s}^{-1}$ )

Given below are two statements : one is labelled as Statement I and the other is labelled as Statement II :

Statement I: Photovoltaic devices can convert optical radiation into electricity.

Statement II: Zener diode is designed to operate under reverse bias in breakdown region.

In the light of the above statements, choose the most appropriate answer from the options given below:

The errors in the measurement which arise due to unpredictable fluctuations in temperature and voltage supply are :

If $\oint_S \vec{E} \cdot d\vec{S} = 0$ over a surface, then :

If the galvanometer $G$ does not show any deflection in the circuit shown, the value of $R$ is given by :

An ac source is connected to a capacitor $C$. Due to decrease in its operating frequency :

The minimum wavelength of X-rays produced by an electron accelerated through a potential difference of V volts is proportional to:

The venturi-meter works on :

A metal wire has mass $(0.4 \pm 0.002) \mathrm{g}$, radius $(0.3 \pm 0.001) \mathrm{mm}$ and length $(5 \pm 0.02) \mathrm{cm}$. The maximum possible percentage error in the measurement of density will nearly be:

Given below are two statements : one is labelled as Statement I and the other is labelled as Statement II :

Statement I: If screen is moved away from the plane of slits, angular separation of the fringes remains constant.

Statement II: If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases.

In the light of the above statements, choose the most appropriate answer from the options given below:

The potential energy of a long spring when stretched by 2 cm is $U$. If the spring is stretched by 8 cm , potential energy stored in it will be :

Light travels a distance $x$ in time $t_{1}$ in air and $10 x$ in time $t_{2}$ in another denser medium. What is the critical angle for this medium?

A $12 \mathrm{~V}, 60 \mathrm{~W}$ lamp is connected to the secondary of a step down transformer, whose primary is connected to ac mains of 220 V . Assuming the transformer to be ideal, what is the current in the primary winding?

A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is :

The angular acceleration of a body, moving along the circumference of a circle, is :

A bullet is fired from a gun at the speed of $280 \mathrm{~m} \mathrm{~s}^{-1}$ in the direction $30^{\circ}$ above the horizontal. The maximum height attained by the bullet is $\left(\mathrm{g}=9.8 \mathrm{~m} \mathrm{~s}^{-2}, \sin 30^{\circ}=0.5\right)$ :

The net magnetic flux through any closed surface is :

The equivalent capacitance of the system shown in the following circuit is :

A vehicle travels half the distance with speed $\vartheta$ and the remaining distance with speed $2 \vartheta$. Its average speed is:

The half life of a radioactive substance is 20 minutes. In how much time, the activity of substance drops to $\left(\frac{1}{16}\right)^{\text {th }}$ of its initial value?

The temperature of a gas is $-50^\circ\mathrm{C}$. To what temperature should the gas be heated so that the rms speed becomes 4 times its initial value?

The magnetic energy stored in an inductor of inductance $4 \mu \mathrm{H}$ carrying a current of 2 A is :

Let a wire be suspended from the ceiling (rigid support) and stretched by a weight $W$ attached at its free end. The longitudinal stress at any point of cross-sectional area $A$ of the wire is :

An electric dipole is placed at an angle of $30^{\circ}$ with an electric field of intensity $2 \times 10^{5} \mathrm{~N} \mathrm{C}^{-1}$. It experiences a torque equal to 4 N m . Calculate the magnitude of charge on the dipole, if the dipole length is 2 cm .

In hydrogen spectrum, the shortest wavelength in the Balmer series is $\lambda$. The shortest wavelength in the Brackett series is

The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is :

Two bodies of mass $m$ and $9m$ are placed at a distance $R$. The gravitational potential on the line joining the bodies where the gravitational field equals zero, will be ( $G$ = gravitational constant):

A bullet from a gun is fired on a rectangular wooden block with velocity $u$. When bullet travels 24 cm through the block along its length horizontally, velocity of bullet becomes $\frac{u}{3}$. Then it further penetrates into the block in the same direction before coming to rest exactly at the other end of the block. The total length of the block is :

The radius of inner most orbit of hydrogen atom is $5.3 \times 10^{-11} \mathrm{~m}$. What is the radius of third allowed orbit of hydrogen atom?

Calculate the maximum acceleration of a moving car so that a body lying on the floor of the car remains stationary. The coefficient of static friction between the body and the floor is $0.15\left(\mathrm{~g}=10 \mathrm{~m} \mathrm{~s}^{-2}\right)$.

10 resistors, each of resistance $R$ are connected in series to a battery of emf $E$ and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased $n$ times. The value of $n$ is :

A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically upwards with a velocity $4 \mathrm{~m} \mathrm{~s}^{-1}$. The ball strikes the water surface after 4 s . The height of bridge above water surface is (Take $\mathrm{g}=10 \mathrm{~m} \mathrm{~s}^{-2}$ ):

The net impedance of circuit (as shown in figure) will be :

A satellite is orbiting just above the surface of the earth with period $T$. If $d$ is the density of the earth and $G$ is the universal constant of gravitation, the quantity $\frac{3 \pi}{G d}$ represents :

Two thin lenses are of same focal lengths $(f)$, but one is convex and the other one is concave. When they are placed in contact with each other, the equivalent focal length of the combination will be :

For the following logic circuit, the truth table is:

A very long conducting wire is bent in a semi-circular shape from $A$ to $B$ as shown in figure. The magnetic field at point $P$ for steady current configuration is given by :

The resistance of platinum wire at $0^{\circ} \mathrm{C}$ is $2 \Omega$ and $6.8 \Omega$ at $80^{\circ} \mathrm{C}$. The temperature coefficient of resistance of the wire is :

An electric dipole is placed as shown in the figure. The electric potential (in $10^{2} \mathrm{~V}$ ) at point P due to the dipole is $\left(\epsilon_{0}=\right.$ permittivity of free space and $\frac{1}{4 \pi \epsilon_{0}}=K$ ):

In the figure shown here, what is the equivalent focal length of the combination of lenses (Assume that all layers are thin)?

A wire carrying a current $I$ along the positive $x$-axis has length $L$. It is kept in a magnetic field $\vec{B} = (2\hat{i} + 3\hat{j} - 4\hat{k})\, \text{T}$. The magnitude of the magnetic force acting on the wire is:

The $x-t$ graph of a particle performing simple harmonic motion is shown in the figure. The acceleration of the particle at $t=2 \mathrm{~s}$ is :

The stability of $\mathrm{Cu}^{2+}$ is more than $\mathrm{Cu}^{+}$salts in aqueous solution due to -

Which one is an example of heterogenous catalysis?

Which amongst the following options is correct graphical representation of Boyle's Law?

Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): A reaction can have zero activation energy.

Reason (R): The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy.

In light of the above statements, choose the most appropriate answer from the options given below:

In Lassaigne's extract of an organic compound, both nitrogen and sulphur are present, which gives blood red colour with $\mathrm{Fe}^{3+}$ due to the formation of -

For a certain reaction, the rate $=k[A]^{2}[B]$, when the initial concentration of $A$ is tripled keeping concentration of B constant, the initial rate would

Match List - I with List - II Choose the correct answer from the options given below :

A compound is formed by two elements A and B. The element B forms cubic close packed structure and atoms of A occupy $1 / 3$ of tetrahedral voids. If the formula of the compound is $A_{x} B_{y}$, then the value of $\mathrm{x}+\mathrm{y}$ is in option

Homoleptic complex from the following complexes is :

The correct order of energies of molecular orbitals of $N_2$ molecule, is:

Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Helium is used to dilute oxygen in diving apparatus.

Reason (R): Helium has high solubility in $\mathrm{O}_{2}$.

In light of the above statements, choose the most appropriate answer from the options given below:

Select the correct statements from the following :

A. Atoms of all elements are composed of two fundamental particles.

B. The mass of the electron is $9.10939 \times 10^{-31} \mathrm{~kg}$.

C. All the isotopes of a given element show same chemical properties.

D. Protons and electrons are collectively known as nucleons.

E. Dalton's atomic theory, regarded the atom as an ultimate particle of matter.

In the light of the above statements, choose the most appropriate answer from the options given below:

The given compound is an example of ___ .

Identify product (A) in the following reaction:

The conductivity of centimolar solution of KCl at $25^{\circ} \mathrm{C}$ is $0.0210 \mathrm{ohm}^{-1} \mathrm{~cm}^{-1}$ and the resistance of the cell containing the solution at $25^{\circ} \mathrm{C}$ is 60 ohm . The value of cell constant is -

Amongst the given options, which of the following molecules/ions acts as a Lewis acid?

The relation between $n_{m},\left(n_{m}=\right.$ the number of permissible values of magnetic quantum number (m)) for a given value of azimuthal quantum number $(l)$, is

Intermolecular forces are forces of attraction and repulsion between interacting particles that will include :

A. dipole - dipole forces.

B. dipole - induced dipole forces.

C. hydrogen bonding.

D. covalent bonding.

E. dispersion forces.

Choose the most appropriate answer from the options given below :

The element expected to form largest ion to achieve the nearest noble gas configuration is :

Some tranquilizers are listed below. Which one from the following belongs to barbiturates?

Which amongst the following molecules on polymerization produces neoprene?

Options: A) H₂C=C(Cl)CH=CH₂ B) H₂C=CH-C≡CH C) H₂C=CH-CH=CH₂ D) H₂C=C(CH₃)CH=CH₂

The right option for the mass of $\mathrm{CO}_{2}$ produced by heating 20 g of $20 \%$ pure limestone is

(Atomic mass of $\mathrm{Ca}=40$ ) $\left[\mathrm{CaCO}_{3} \xrightarrow{1200 \mathrm{~K}} \mathrm{CaO}+\mathrm{CO}_{2}\right]$

The number of $\sigma$ bonds, $\pi$ bonds and lone pairs of electrons in pyridine, respectively, are:

Which amongst the following options is the correct relation between change in enthalpy and change in internal energy?

Which of the following statements are INCORRECT?

A. All the transition metals except scandium form $MO$ oxides which are ionic.

B. The highest oxidation number corresponding to the group number in transition metal oxides is attained in $\mathrm{Sc}_{2} \mathrm{O}_{3}$ to $\mathrm{Mn}_{2} \mathrm{O}_{7}$.

C. Basic character increases from $\mathrm{V}_{2} \mathrm{O}_{3}$ to $\mathrm{V}_{2} \mathrm{O}_{4}$ to $\mathrm{V}_{2} \mathrm{O}_{5}$.

D. $\mathrm{V}_{2} \mathrm{O}_{4}$ dissolves in acids to give $\mathrm{VO}_{4}^{3-}$ salts.

E. $\mathrm{CrO}$ is basic but $\mathrm{Cr}_{2} \mathrm{O}_{3}$ is amphoteric.

In the light of the above statements, choose the most appropriate answer from the options given below:

What fraction of one edge centred octahedral void lies in one unit cell of fcc?

The equilibrium concentrations of the species in the reaction $A + B \rightleftharpoons C + D$ are 2, 3, 10 and 6 $\mathrm{mol\,L^{-1}}$, respectively at 300 K. $\Delta G^\circ$ for the reaction is ( $R = 2\ \mathrm{cal\,mol^{-1}\,K^{-1}}$).

Which complex compound is most stable?

On balancing the given redox reaction, $a\ce{Cr2O7^{2-}} + b\ce{SO3^{2-}}(aq) + c\ce{H+}(aq) \rightarrow 2a\ce{Cr^{3+}}(aq) + b\ce{SO4^{2-}}(aq) + \frac{c}{2}\ce{H2O}(l)$, the coefficients $a, b$ and $c$ are found to be, respectively -

Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II.

Statement I: The nutrient deficient water bodies lead to eutrophication.

Statement II: Eutrophication leads to decrease in the level of oxygen in the water bodies.

In the light of the above statements, choose the most appropriate answer from the options given below:

Match List - I with List- II : List - I

Choose the correct answer from the options given below :

Which hormone promotes internode/petiole elongation in deep water rice?

Large, colourful, fragrant flowers with nectar are seen in :

The historic Convention on Biological Diversity, 'The Earth Summit' was held in Rio de Janeiro in the year :

During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out

How many ATP and $\mathrm{NADPH}_{2}$ are required for the synthesis of one molecule of Glucose during Calvin cycle?

In the equation

GPP is Gross Primary Productivity

NPP is Net Primary Productivity R here is ____ .

In gene gun method used to introduce alien DNA into host cells, microparticles of_____ metal are used.

The phenomenon of pleiotropism refers to

Among eukaryotes, replication of DNA takes place in -

Family Fabaceae differs from Solanaceae and Liliaceae. With respect to the stamens, pick out the characteristics specific to family Fabaceae but not found in Solanaceae or Liliaceae.

Axile placentation is observed in

Identify the pair of heterosporous pteridophytes among the following :

What is the function of tassels in the corn cob?

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A): The first stage of gametophyte in the life cycle of moss is protonema stage.

Reason (R): Protonema develops directly from spores produced in capsule.

In light of the above statements, choose the most appropriate answer from the options given below.

Spraying of which of the following phytohormone on juvenile conifers helps in hastening the maturity period, that leads to early seed production?

Frequency of recombination between gene pairs on same chromosome as a measure of the distance between genes to map their position on chromosome, was used for the first time by

Expressed Sequence Tags (ESTs) refers to

Upon exposure to UV radiation, DNA stained with ethidium bromide will show

Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)

Assertion (A): ATP is used at two steps in glycolysis.

Reason (R): First ATP is used in converting glucose into glucose-6-phosphate and second ATP is used in conversion of fructose-6phosphate into fructose-1-6-diphosphate.

In light of the above statements, choose the most appropriate answer from the options given below.

Unequivocal proof that DNA is the genetic material was first proposed by

Identify the correct statements: A. Detritivores perform fragmentation. B. The humus is further degraded by some microbes during mineralization. C. Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching. D. The detritus food chain begins with living organisms. E. Earthworms break down detritus into smaller particles by a process called catabolism. In the light of the above statements, choose the most appropriate answer from the options given below:

The reaction centre in PS II has an absorption maxima at

In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are :

Which of the following stages of meiosis involves division of centromere?

Among 'The Evil Quartet', which one is considered the most important cause driving extinction of species?

What is the role of RNA polymerase III in the process of transcription in Eukaryotes?

Given below are two statements : one is labelled as Statement I and the other is labelled as Statement II :

Statement I: Endarch and exarch are the terms often used for describing the position of secondary xylem in the plant body.

Statement II: Exarch condition is the most common feature of the root system.

In the light of the above statements, choose the most appropriate answer from the options given below: