NEET 2025 — Code 48

A parallel plate capacitor made of circular plates is being charged such that the surface charge density on its plates is increasing at a constant rate with time. The magnetic field arising due to displacement current is:

An electric dipole with dipole moment $5\times 10^{-6}\text{C m}$ is aligned with the direction of a uniform electric field of magnitude $4\times 10^5\text{N/C}$. The dipole is then rotated through an angle of $60^{\circ }$ with respect to the electric field. The change in the potential energy of the dipole is:

A ball of mass 0.5 kg is dropped from a height of 40 m. The ball hits the ground and rises to a height of 10 m. The impulse imparted to the ball during its collision with the ground is (Take $g=9.8{\text{ m/s}}^2$)

The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at $22.5^{\circ }$ from the polarization axis of one of the polaroids, is ($I_0$ is the intensity of polarised light after passing through the first polaroid):

The kinetic energies of two similar cars A and B are 100 J and 225 J respectively. On applying brakes, car A stops after 1000 m and car B stops after 1500 m. If $F_A$ and $F_B$ are the forces applied by the brakes on cars A and B respectively, then the ratio of $\frac{F_A}{F_B}$ is

The current passing through the battery in the given circuit, is:

Three identical heat conducting rods are connected in series as shown in the figure. The rods on the sides have thermal conductivity $2K$ while that in the middle has thermal conductivity $K$. The left end of the combination is maintained at temperature $3T$ and the right end at $T$. The rods are thermally insulated from outside. In steady state, temperature at the left junction is $T_1$ and that at the right junction is $T_2$. The ratio $T_1/T_2$ is

In an oscillating spring mass system, a spring is connected to a box filled with sand. As the box oscillates, sand leaks slowly out of the box vertically so that the average frequency $\omega (t)$ and average amplitude $A(t)$ of the system change with time $t$. Which one of the following options schematically depicts these changes correctly?

AB is a part of an electrical circuit (see figure). The potential difference "$V_A-V_B$", at the instant when current $i=2\text{A}$ and is increasing at a rate of 1 amp/second is:

A particle of mass $m$ is moving around the origin with a constant force $F$ pulling it towards the origin. If Bohr model is used to describe its motion, the radius of the $n^{\text{th}}$ orbit and the particle's speed $v$ in the orbit depend on $n$ as

In some appropriate units, time (t) and position (x) relation of a moving particle is given by $t=x^2+x$. The acceleration of the particle is

A model for quantized motion of an electron in a uniform magnetic field $B$ states that the flux passing through the orbit of the electron is $n(h/e)$ where $n$ is an integer, $h$ is Planck's constant and $e$ is the magnitude of electron's charge. According to the model, the magnetic moment of an electron in its lowest energy state will be ($m$ is the mass of the electron)

A microscope has an objective of focal length 2 cm, eyepiece of focal length 4 cm and the tube length of 40 cm. If the distance of distinct vision of eye is 25 cm, the magnification in the microscope is

There are two inclined surfaces of equal length ($L$) and same angle of inclination $45^{\circ }$ with the horizontal. One of them is rough and the other is perfectly smooth. A given body takes 2 times as much time to slide down on rough surface than on the smooth surface. The coefficient of kinetic friction (${\mu }_k$) between the object and the rough surface is close to

A full wave rectifier circuit with diodes ($D_1$) and ($D_2$) is shown in the figure. If input supply voltage $V_{in}=220\sin (100\pi t)$ volt, then at $t=15$ msec

A uniform rod of mass 20 kg and length 5 m leans against a smooth vertical wall making an angle of $60^{\circ }$ with it. The other end rests on a rough horizontal floor. The friction force that the floor exerts on the rod is (Take $g=10{\text{m/s}}^2$)

Two identical charged conducting spheres A and B have their centres separated by a certain distance. Charge on each sphere is $q$ and the force of repulsion between them is $F$. A third identical uncharged conducting sphere is brought in contact with sphere A first and then with B and finally removed from both. New force of repulsion between spheres A and B (Radii of A and B are negligible compared to the distance of separation so that for calculating force between them they can be considered as point charges) is best given as:

Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every $T$ min. A girl is driving scooty with a speed of 60 km/h in the direction X to Y notices that a bus goes past her every 30 minutes in the direction of her motion, and every 10 minutes in the opposite direction. Choose the correct option for the period $T$ of the bus service and the speed (assumed constant) of the buses.

A container has two chambers of volumes $V_1=2$ litres and $V_2=3$ litres separated by a partition made of a thermal insulator. The chambers contain $n_1=5$ and $n_2=4$ moles of ideal gas at pressures $p_1=1$ atm and $p_2=2$ atm, respectively. When the partition is removed, the mixture attains an equilibrium pressure of

De-Broglie wavelength of an electron orbiting in the $n=2$ state of hydrogen atom is close to (Given Bohr radius = 0.052 nm)

To an ac power supply of 220 V at 50 Hz, a resistor of 20 $\Omega$, a capacitor of reactance 25 $\Omega$ and an inductor of reactance 45 $\Omega$ are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is, respectively

Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis?

A pipe open at both ends has a fundamental frequency $f$ in air. The pipe is now dipped vertically in a water drum to half of its length. The fundamental frequency of the air column is now equal to:

Two identical point masses $P$ and $Q$, suspended from two separate massless springs of spring constants $k_1$ and $k_2$, respectively, oscillate vertically. If their maximum speeds are the same, the ratio $(A_Q/A_P)$ of the amplitude $A_Q$ of mass $Q$ to the amplitude $A_P$ of mass $P$ is

The output (Y) of the given logic implementation is similar to the output of an/a ____ gate.

An oxygen cylinder of volume 30 litre has 18.20 moles of oxygen. After some oxygen is withdrawn from the cylinder, its gauge pressure drops to 11 atmospheric pressure at temperature 27°C. The mass of the oxygen withdrawn from the cylinder is nearly equal to: [Given, $R=\frac{100}{12}{\text{J mol}}^{-1}{\text{K}}^{-1}$, and molecular mass of $O_2=32$, 1 atm pressure = $1.01\times 10^5\text{N/m}$]

In a certain camera, a combination of four similar thin convex lenses are arranged axially in contact. Then the power of the combination and the total magnification in comparison to the power ($p$) and magnification ($m$) for each lens will be, respectively

Two gases A and B are filled at the same pressure in separate cylinders with movable pistons of radius $r_A$ and $r_B$, respectively. On supplying an equal amount of heat to both the systems reversibly under constant pressure, the pistons of gas A and B are displaced by 16 cm and 9 cm, respectively. If the change in their internal energy is the same, then the ratio $\frac{r_A}{r_B}$ is equal to

A balloon is made of a material of surface tension $S$ and its inflation outlet (from where gas is filled in it) has small area $A$. It is filled with a gas of density $\rho$ and takes a spherical shape of radius $R$. When the gas is allowed to flow freely out of it, its radius $r$ changes from $R$ to $0$ (zero) in time $T$. If the speed $v(r)$ of gas coming out of the balloon depends on $r$ as $r^{\alpha }$ and $T\propto S^{\alpha }{A}^{\beta }{\rho }^{\gamma }{R}^{\delta }$ then

A bob of heavy mass $m$ is suspended by a light string of length $l$. The bob is given a horizontal velocity $v_0$ as shown in figure. If the string gets slack at some point $P$ making an angle $\theta$ from the horizontal, the ratio of the speed $v$ of the bob at point $P$ to its initial speed $v_0$ is:

A physical quantity $P$ is related to four observations $a,b,c$ and $d$ as follows: $P=a^3{b}^2/c\sqrt{d}$ The percentage errors of measurement in $a,b,c$ and $d$ are $1\%$, $3\%$, $2\%$, and $4\%$ respectively. The percentage error in the quantity $P$ is

The Sun rotates around its centre once in 27 days. What will be the period of revolution if the Sun were to expand to twice its present radius without any external influence? Assume the Sun to be a sphere of uniform density.

The radius of Martian orbit around the Sun is about 4 times the radius of the orbit of Mercury. The Martian year is 687 Earth days. Then which of the following is the length of 1 year on Mercury?

A wire of resistance $R$ is cut into 8 equal pieces. From these pieces two equivalent resistances are made by adding four of these together in parallel. Then these two sets are added in series. The net effective resistance of the combination is:

A photon and an electron (mass $m$) have the same energy $E$. The ratio (${\lambda }_{photon}/{\lambda }_{electron}$) of their de Broglie wavelengths is: ($c$ is the speed of light)

A sphere of radius $R$ is cut from a larger solid sphere of radius $2R$ as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is:

An electron (mass $9\times 10^{-31}$ kg and charge $1.6\times 10^{-19}$ C) moving with speed $c/100$ ($c=$ speed of light) is injected into a magnetic field $\vec{B}$ of magnitude $9\times 10^{-4}$ T perpendicular to its direction of motion. We wish to apply an uniform electric field $\vec{E}$ together with the magnetic field so that the electron does not deflect from its path. Then (speed of light $c=3\times 10^8$ ms${}^{-1}$)

The electric field in a plane electromagnetic wave is given by $E_z=60\cos (5x+1.5\times 10^{9}t)\text{ V/m}$. Then expression for the corresponding magnetic field is (here subscripts denote the direction of the field):

A body weighs 48 N on the surface of the earth. The gravitational force experienced by the body due to the earth at a height equal to one-third the radius of the earth from its surface is :

An unpolarized light beam travelling in air is incident on a medium of refractive index 1.73 at Brewster’s angle. Then

A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is:

The plates of a parallel plate capacitor are separated by $d$. Two slabs of different dielectric constant $K_1$ and $K_2$ with thickness $\frac{3}{8}d$ and $\frac{d}{2}$, respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between the plates. If $K_1=1.25K_2$, the value of $K_1$ is:

Consider the diameter of a spherical object being measured with the help of a Vernier callipers. Suppose its 10 Vernier Scale Divisions (V.S.D.) are equal to its 9 Main Scale Divisions (M.S.D.). The least division in the M.S. is 0.1 cm and the zero of V.S. is at $x=0.1$ cm when the jaws of Vernier callipers are closed. If the main scale reading for the diameter is $M=5$ cm and the number of coinciding vernier division is 8, the measured diameter after zero error correction, is

A 2 amp current is flowing through two different small circular copper coils having radii ratio 1 : 2. The ratio of their respective magnetic moments will be

Consider a water tank shown in the figure. It has one wall at $x=L$ and can be taken to be very wide in the $z$ direction. When filled with a liquid of surface tension $S$ and density $\rho$, the liquid surface makes angle ${\theta }_0$ (${\theta }_0<<1$) with the $x$-axis at $x=L$. If $y(x)$ is the height of the surface then the equation for $y(x)$ is: (take $\theta (x)=\sin \theta (x)=\tan \theta (x)=\frac{dy}{dx}$, $g$ is the acceleration due to gravity)

Identify the suitable reagent for the following conversion.

The correct order of decreasing acidity of the following aliphatic acids is

Which one of the following reactions does NOT belong to "Lassaigne's test"?

If the rate constant of a reaction is $0.03{\text{s}}^{-1}$, how much time does it take for $7.2{\text{mol L}}^{-1}$ concentration of the reactant to get reduced to $0.9{\text{mol L}}^{-1}$? (Given: $\log 2=0.301$)

Given below are two statements : Statement I : A hypothetical diatomic molecule with bond order zero is quite stable. Statement II : As bond order increases, the bond length increases. In the light of the above statements, choose the most appropriate answer from the options given below :

Out of the following complex compounds, which of the compound will be having the minimum conductance in solution?

Which of the following aqueous solution will exhibit highest boiling point?

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Compound (I) undergoes $S_{N}2$ reaction faster than Compound (II). Reason (R): Iodine is a better leaving group because of its large size. In the light of the above statements, choose the correct answer from the options given below:

Consider the following compounds : $\underline{K}{O}_2$, $H_2{\underline{O}}_2$ and $H_2\underline{S}{O}_4$ The oxidation state of the underlined elements in them are, respectively,

Match List-I with List-II.

Given below are two statements : Statement I : Like nitrogen that can form ammonia, arsenic can form arsine. Statement II : Antimony cannot form antimony pentoxide. In the light of the above statements, choose the most appropriate answer from the options given below :

Given below are two statements : Statement I : Ferromagnetism is considered as an extreme form of paramagnetism. Statement II : The number of unpaired electrons in a Cr²⁺ ion (Z = 24) is the same as that of a Nd³⁺ ion (Z = 60). In the light of the above statements, choose the correct answer from the options given below :

Which one of the following reactions does NOT belong to "Lassaigne's test"?

Match List-I with List-II.

How many products (including stereoisomers) are expected from monochlorination of the following compound?

Which of the following statements are true? A. Unlike Ga that has a very high melting point, Cs has a very low melting point. B. On Pauling scale, the electronegativity values of N and Cl are not the same. C. Ar, K⁺, Cl⁻, Ca²⁺, and S²⁻ are all isoelectronic species. D. The correct order of the first ionization enthalpies of Na, Mg, Al, and Si is Si > Al > Mg > Na. E. The atomic radius of Cs is greater than that of Li and Rb. Choose the correct answer from the options given below :

The standard heat of formation, in kcal/mol of $B{a}^{2+}$ is : [Given : standard heat of formation of $S{O}_4^{2-}$ ion (aq) = $-216$ kcal/mol, standard heat of crystallisation of $BaS{O}_4(s)$ = $-4.5$ kcal/mol, standard heat of formation of $BaS{O}_4(s)$ = $-349$ kcal/mol]

C(s) + 2H₂(g) → CH₄(g); $\Delta H=-74.8$ kJ mol⁻¹. Which of the following diagrams gives an accurate representation of the above reaction? [R → reactants; P → products]

Sugar 'X' A. is found in honey B. is a keto sugar C. exists in $\alpha$ and $\beta$ - anomeriс forms. D. Is laevorotatory. 'X' is :

Total number of possible isomers (both structural as well as stereoisomers) of cyclic ethers of molecular formula $C_4{H}_{8}O$ is :

For the reaction $A(g)\rightleftharpoons 2B(g)$, the backward reaction rate constant is higher than the forward reaction rate constant by a factor of 2500, at 1000 K. [Given : $R=0.0831{\text{ L atm mol}}^{-1}{\text{ K}}^{-1}$] $K_P$ for the reaction at 1000 K is

The ratio of the wavelengths of the light absorbed by a Hydrogen atom when it undergoes $n=2\to n=3$ and $n=4\to n=6$ transitions, respectively, is

If the molar conductivity (${\Lambda }_m$) of a 0.050 mol L${}^{-1}$ solution of a monobasic weak acid is 90 S cm${}^2$ mol${}^{-1}$, its extent (degree) of dissociation will be [Assume ${\Lambda }_{+}^{\circ }=349.6$ S cm${}^2$ mol${}^{-1}$ and ${\Lambda }_{-}^{\circ }=50.4$ S cm${}^2$ mol${}^{-1}$.]

5 moles of liquid X and 10 moles of liquid Y make a solution having a vapour pressure of 70 torr. The vapour pressures of pure X and Y are 63 torr and 78 torr respectively. Which of the following is true regarding the described solution?

Among the following, choose the ones with equal number of atoms. A. 212 g of $N{a}_{2}C{O}_3(s)$ [molar mass = 106 g] B. 248 g of $N{a}_{2}O(s)$ [molar mass = 62 g] C. 240 g of $NaOH(s)$ [molar mass = 40 g] D. 12 g of $H_2(g)$ [molar mass = 2 g] E. 220 g of $C{O}_2(g)$ [molar mass = 44 g]

Which of the following are paramagnetic?

If the half-life (t₁/₂) for a first order reaction is 1 minute, then the time required for 99.9% completion of the reaction is closest to :

Energy and radius of first Bohr orbit of He⁺ and Li²⁺ are [Given R_H = 2.18 × 10⁻¹⁸ J, a₀ = 52.9 pm]

Among the given compounds I-III, the correct order of bond dissociation energy of C–H bond marked with * is :

Dalton's Atomic theory could not explain which of the following?

Identify the correct orders against the property mentioned A. $H_{2}O>N{H}_3>CHC{l}_3$ – dipole moment B. $Xe{F}_4>Xe{O}_3>Xe{F}_2$ – number of lone pairs on central atom C. $O–H>C–H>N–O$ – bond length D. $N_2>O_2>H_2$ – bond enthalpy

The correct order of decreasing basic strength of the given amines is:

The correct order of the wavelength of light absorbed by the following complexes is, A. $[Co(N{H}_3{)}_6{]}^{3+}$ B. $[Co(CN{)}_6{]}^{3-}$ C. $[Cu(H_{2}O{)}_4{]}^{2+}$ D. $[Ti(H_{2}O{)}_6{]}^{3+}$ Choose the correct answer from the options given below:

Which one of the following compounds does not decolourize bromine water?

Predict the major product P in the following sequence of reactions:

Match List-I with List-II.

Which among the following electronic configurations belong to main group elements? A. $[Ne]3s^1$ B. $[Ar]3d^{3}4s^2$ C. $[Kr]4d^{10}5s^{2}5p^5$ D. $[Ar]3d^{10}4s^1$ E. $[Rn]5f^{0}6d^{2}7s^2$ Choose the correct answer from the option given below :

Which one of the following compounds can exist as cis-trans isomers?

Phosphoric acid ionizes in three steps with their ionization constant values $K_{a_1}$, $K_{a_2}$ and $K_{a_3}$, respectively, while $K$ is the overall ionization constant. Which of the following statements are true? A. $\log K=\log K_{a_1}+\log K_{a_2}+\log K_{a_3}$ B. ${\mathrm{H}}_3\mathrm{P}{\mathrm{O}}_4$ is a stronger acid than ${\mathrm{H}}_2\mathrm{P}{\mathrm{O}}_4^{-}$ and $\mathrm{HP}{\mathrm{O}}_4^{2-}$ C. $K_{a_1}>K_{a_2}>K_{a_3}$ D. $K_{a_1}=\frac{K_{a_3}+K_{a_2}}{2}$

Higher yield of NO in $N_2(g)+O_2(g)\rightleftharpoons 2NO(g)$ can be obtained at [$\Delta H$ of the reaction = +180.7 kJ mol⁻¹]

Given below are two statements : Statement-I : Benzenediazonium salt is prepared by the reaction of aniline with nitrous acid at 273 – 278 K. It decomposes easily in the dry state. Statement-II : Insertion of iodine into the benzene ring is difficult and hence iodobenzene is prepared through the reaction of benzenediazonium salt with KI. In the light of the above statements, choose the most appropriate answer from the options given below :

Predict the major product P in the following sequence of reactions:

In the above represented plasmid, an alien piece of DNA is inserted at EcoRI site. Which of the following strategies will be chosen to select the recombinant colonies?

The protein portion of an enzyme is called:

Given below are two statements: Statement I : The primary source of energy in an ecosystem is solar energy. Statement II : The rate of production of organic matter during photosynthesis in an ecosystem is called net primary productivity (NPP). In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : A typical unfertilised, angiosperm embryo sac at maturity is 8 nucleate and 7-celled. Reason (R) : The egg apparatus has 2 polar nuclei. In the light of the above statements, choose the correct answer from the options given below :

Neoplastic characteristics of cells refer to : A. A mass of proliferating cell B. Rapid growth of cells C. Invasion and damage to the surrounding tissue D. Those confined to original location Choose the correct answer from the options given below:

Which one of the following is the characteristic feature of gymnosperms?

Which chromosome in the human genome has the highest number of genes?

Which of the following statements about RuBisCO is true?

The first menstruation is called :

Which of the following genetically engineered organisms was used by Eli Lilly to prepare human insulin?

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : All vertebrates are chordates but all chordates are not vertebrate. Reason (R) : The members of subphylum vertebrata possess notochord during the embryonic period, the notochord is replaced by cartilaginous or bony vertebral column in adults. In the light of the above statements, choose the correct answer from the options given below:

What is the main function of the spindle fibers during mitosis?

In frog, the Renal portal system is a special venous connection that acts to link :

Which of the following are the post-transcriptional events in an eukaryotic cell?