NEET 2025 Physics Questions

A sphere of radius R is carved out of a uniform solid sphere of radius 2R (internally tangent, so its centre is at distance R from the big centre). The ratio of the moment of inertia of the small sphere to that of the remaining part, both about the Y-axis through the big sphere's centre, is:

The Sun rotates once in 27 days. If it expanded to twice its present radius (uniform-density sphere, no external influence), its new period would be about:

A uniform rod of mass 20 kg and length 5 m leans against a smooth vertical wall, making 60° with the wall; its lower end rests on a rough horizontal floor. The friction force exerted by the floor is: (g = 10 m/s²)

A bob of mass m is suspended by a light string of length l and given a horizontal velocity v₀ at the lowest point. The string goes slack at a point P where it makes an angle θ above the horizontal. The ratio of the speed v at P to the initial speed v₀ is:

A ball of mass 0.5 kg is dropped from a height of 40 m. It hits the ground and rebounds to a height of 10 m. The impulse imparted to the ball during its collision with the ground is (g = 9.8 m/s²):

There are two inclined surfaces of equal length L and the same inclination 45° with the horizontal; one is rough and the other perfectly smooth. A given body takes 2 times as much time to slide down the rough surface as the smooth surface. The coefficient of kinetic friction (μk) between the body and the rough surface is close to:

The diameter of a spherical object is measured with a vernier caliper whose 10 vernier scale divisions (VSD) equal 9 main scale divisions (MSD). The least MSD is 0.1 cm and the zero of the vernier scale is at x = 0.1 cm when the jaws are closed. If the main scale reading for the diameter is M = 5 cm and the coinciding vernier division is 8, the measured diameter after zero-error correction is:

A balloon is made of a material of surface tension S and its inflation outlet (from where gas is filled) has small area A. It is filled with a gas of density ρ 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 in time T. If the speed v(r) of gas coming out depends on r as r^a and T ∝ S^α A^β ρ^γ R^δ, then:

A physical quantity P is related to four observations a, b, c and d as P = a³b²/(c·√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:

A container has two chambers of volumes V₁ = 2 litres and V₂ = 3 litres separated by a partition made of a thermal insulator. The chambers contain n₁ = 5 and n₂ = 4 moles of ideal gas at pressures p₁ = 1 atm and p₂ = 2 atm, respectively. When the partition is removed, the mixture attains an equilibrium pressure of:

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 systems reversibly under constant pressure, the pistons of gas A and gas B are displaced by 16 cm and 9 cm, respectively. If the change in their internal energy is the same, then the ratio r_A/r_B is equal to:

An oxygen cylinder of volume 30 litre has 18.20 moles of oxygen. After some oxygen is withdrawn from the cylinder, its 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 = 100/12 J mol⁻¹ K⁻¹, molecular mass of O₂ = 32, 1 atm = 1.01 × 10⁵ N m⁻²]

Buses leave cities X and Y in both directions at regular intervals of T minutes with the same speed. A girl driving from X to Y at 60 km/h notices that a bus moving in her direction passes her every 30 min, while a bus moving in the opposite direction passes her every 10 min. The interval T and the speed of the buses are respectively:

The relation between time t and position x of a particle moving along a straight line is given by $t = x^2 + x$. The acceleration of the particle is:

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 braking forces on cars A and B respectively, then the ratio F_A/F_B is

A bob of heavy mass m is suspended by a light string of length l. The bob is given a horizontal velocity v₀ at the lowest point. If the string goes slack at some point P making an angle θ from the horizontal, the ratio of the speed v of the bob at P to its initial speed v₀ is

Two identical point masses P and Q, suspended from two separate massless springs of spring constants k₁ and k₂ respectively, oscillate vertically. If their maximum speeds are the same, the ratio A_Q/A_P of the amplitude of mass Q to that of mass P 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 the average angular frequency ω(t) and the average amplitude A(t) of the system change with time t. Which option correctly and schematically depicts these changes?

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

The radius of the Martian orbit around the Sun is about 4 times the radius of Mercury's orbit. The Martian year is 687 earth days. The length of one year on Mercury is about:

A balloon is made of a material of surface tension S and its inflation outlet (from where gas is filled) has small area A. It is filled with a gas of density ρ and takes a spherical shape of radius R. When the gas flows freely out, its radius r changes from R to 0 in time T. If the speed v(r) of gas coming out depends on r as rᵅ and T ∝ Sᵝ Aᵞ Rᵟ ρᵋ, then:

Consider a water tank with one wall at x = L, very wide in the z-direction. When filled with a liquid of surface tension S and density ρ, the liquid surface makes a small angle θ₀ (0 < θ₀ ≪ 1) with the x-axis at x = L. If y(x) is the height of the surface, the equation for y(x) is: (take sinθ(x) ≈ tanθ(x) = dy/dx, g = acceleration due to gravity)

Three identical heat-conducting rods are connected in series as shown. The two side rods have thermal conductivity 2K and the middle rod has thermal conductivity K. The left end is maintained at 3T and the right end at T; the rods are insulated from the sides. In steady state the left junction is at T₁ and the right junction is at T₂. The ratio T₁ : T₂ is:

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

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 gases reversibly at constant pressure, the pistons of 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 $\dfrac{r_A}{r_B}$ is

An electric dipole with dipole moment 5 × 10⁻⁶ C·m is aligned with the direction of a uniform electric field of magnitude 4 × 10⁵ N/C. The dipole is then rotated through an angle of 60° with respect to the electric field. The change in the potential energy of the dipole is:

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 negligible vs separation, treated as point charges) is best given as:

The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant K1 and K2 with thickness 3d/8 and 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 K1/K2 = 1.25, the value of K1 is:

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

An electron (mass 9 × 10⁻³¹ kg and charge 1.6 × 10⁻¹⁹ C) moving with speed c/100 (c = speed of light) is injected into a magnetic field B of magnitude 9 × 10⁻⁴ T perpendicular to its direction of motion. We wish to apply a uniform electric field E together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c = 3 × 10⁸ m s⁻¹)

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 wire of resistance R is cut into 8 equal pieces. Two sets are made by joining four pieces in parallel each; the two sets are then in series. The net resistance is:

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

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

A photon and an electron (mass m) have the same energy E. The ratio λ_photon/λ_electron of their de Broglie wavelengths is: (c is the speed of light)

The de Broglie wavelength of an electron in the n = 2 state of the hydrogen atom is close to (Given Bohr radius a₀ = 0.052 nm):

Which of the following options represents the variation of photoelectric current with the property of light (intensity) shown on the x-axis?

A full wave rectifier circuit with diodes D₁ and D₂ is shown in the figure. If the input supply voltage is V_in = 220 sin(100πt) volt, then at t = 15 ms:

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

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

The de Broglie wavelength of an electron in the n = 2 state of hydrogen atom is close to: (Given Bohr radius = 0.052 nm)

A polaroid sheet is placed between two crossed polaroids, with its polarization axis at 22.5° from the polarization axis of one of the polaroids. The intensity of the transmitted light is (I₀ is the intensity of polarized light after passing through the first polaroid)

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

An electric dipole with dipole moment 5 × 10⁻⁶ C m is aligned with the direction of a uniform electric field of magnitude 4 × 10⁵ N/C. The dipole is then rotated through an angle of 60° with respect to the electric field. The change in the potential energy of the dipole is:

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. The new force of repulsion between spheres A and B (radii of A and B are negligible compared to the distance of separation, so for calculating the force between them they can be considered as point charges) is best given as:

The electric field in a plane electromagnetic wave is given by E_z = 60 cos(5x + 1.5×10⁹ t) V/m. Then the expression for the corresponding magnetic field is (subscripts denote field direction)

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 the displacement current is

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:

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

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

AB is a part of an electrical circuit (see figure). The branch contains an inductor of 1 H, a 5 V battery, and a 2 ohm resistor in series between A and B. The potential difference "V_A - V_B", at the instant when current i = 2 A and is increasing at a rate of 1 amp/second is: