NEET 2025 Physics Question Paper (Available): Download NEET 2025 Answer key Code 46

A physical quantity \(P\) is related to four observations \(a\), \(b\), \(c\), and \(d\) as follows: \(\)P = a^3 b^2 
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:

• (1) \( 2% \)
• (2) \( 13% \)
• (3) \( 15% \)
• (4) \( 10% \)

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 (\(I_0\) is the intensity of polarised light after passing through the first polaroid):

• (1) \( \frac{I_0}{4} \)
• (2) \( \frac{I_0}{8} \)
• (3) \( \frac{I_0}{16} \)
• (4) \( \frac{I_0}{2} \)

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:

• (1) \( 1:2 \)
• (2) \( 2:1 \)
• (3) \( 4:1 \)
• (4) \( 1:4 \)

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 count in the M.S. is 0.1 cm and the zero of V.S. is at -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:

• (1) \( 5.08 cm \)
• (2) \( 4.98 cm \)
• (3) \( 5.09 cm \)
• (4) \( 5.18 cm \)

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

• (1) \( c \sqrt{2mE} \)
• (2) \( \frac{c \sqrt{2m}}{E} \)
• (3) \( c \sqrt{\frac{E}{2m}} \)
• (4) \( \sqrt{\frac{E}{2m}} \)

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

• (1) \( 0.67 nm \)
• (2) \( 1.67 nm \)
• (3) \( 2.67 nm \)
• (4) \( 0.067 nm \)

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

• (1) reflected light is partially polarized and the angle of reflection is close to \(30^\circ\)
• (2) both reflected and transmitted light are perfectly polarized with angles of reflection and refraction close to \(60^\circ\) and \(30^\circ\), respectively
• (3) transmitted light is completely polarized and the angle of refraction is close to \(30^\circ\)
• (4) reflected light is completely polarized and the angle of reflection is close to \(60^\circ\)

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 \( \frac{F_A}{F_B} \) is:

• (1) \( \frac{1}{2} \)
• (2) \( \frac{1}{4} \)
• (3) \( \frac{2}{3} \)
• (4) \( \frac{4}{3} \)

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 are added in series. The net effective resistance of the combination is:

• (1) \( \frac{R}{32} \)
• (2) \( \frac{R}{4} \)
• (3) \( \frac{R}{8} \)
• (4) \( \frac{R}{6} \)

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 \(27^\circ\)C. The mass of the oxygen withdrawn from the cylinder is nearly equal to:
[Given, \(R = \frac{100}{12} J mol^{-1} K^{-1}\), and molecular mass of \(O_2 = 32 g/mol\), 1 atm pressure = \(1.01 \times 10^5 N/m^2\)]

• (1) \( 0.144 kg \)
• (2) \( 0.116 kg \)
• (3) \( 0.156 kg \)
• (4) \( 0.125 kg \)

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 one lens will be, respectively:

• (1) \( 4p \) and \( m^4 \)
• (2) \( p \) and \( 4m \)
• (3) \( p \) and \( m^4 \)
• (4) \( 4p \) and \( 4m \)

AB is a part of an electrical circuit (see figure). 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:

• (1) \( 6 volt \)
• (2) \( 9 volt \)
• (3) \( 10 volt \)
• (4) \( 5 volt \)

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:

• (1) \( 27 N \)
• (2) \( 32 N \)
• (3) \( 36 N \)
• (4) \( 16 N \)

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:

• (1) \( D_1 \) is reverse biased, \( D_2 \) is forward biased
• (2) \( D_1 \) and \( D_2 \) both are forward biased
• (3) \( D_1 \) and \( D_2 \) both are reverse biased
• (4) \( D_1 \) is forward biased, \( D_2 \) is reverse biased

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. She 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.

• (1) \( 25 min, 100 km/h \)
• (2) \( 10 min, 90 km/h \)
• (3) \( 15 min, 120 km/h \)
• (4) \( 9 min, 40 km/h \)

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.

• (1) \( 108 days \)
• (2) \( 115 days \)
• (3) \( 100 days \)
• (4) \( 54 days \)

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

• (1) \( B_y = 2 \times 10^{-7} \cos(5x + 1.5 \times 10^{10} t) T \)
• (2) \( B_y = 60 \cos(5x + 1.5 \times 10^{10} t) T \)
• (3) \( B_y = 60 \times 10^9 \cos(5x + 1.5 \times 10^{10} t) T \)
• (4) \( B_y = -2 \times 10^{-7} \cos(5x + 1.5 \times 10^{10} t) T \)

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 C is brought in contact with sphere A first and then with sphere B and finally removed from both. New force of repulsion between spheres A and B (Radius of A and B are negligible compared to the distance of separation so that they can be considered as point charges) is best given as:

• (1) \( \frac{2F}{3} \)
• (2) \( \frac{F}{2} \)
• (3) \( \frac{3F}{8} \)
• (4) \( \frac{3F}{4} \)

An electric dipole with dipole moment \(p = 5 \times 10^{-6}\) Cm is aligned with the direction of a uniform electric field of magnitude \(E = 4 \times 10^5\) 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:

• (1) \( 1.0 J \)
• (2) \( 1.2 J \)
• (3) \( 1.5 J \)
• (4) \( 0.8 J \)

A microscope has an objective of focal length \(f_o = 2\) cm and an eyepiece of focal length \(f_e = 4\) cm. The tube length of the microscope is \(L = 40\) cm. If the distance of distinct vision of eye is \(D = 25\) cm, the magnification in the microscope is:

• (1) \( 125 \)
• (2) \( 150 \)
• (3) \( 250 \)
• (4) \( 100 \)

The output (Y) of the given logic implementation is similar to the output of an/a 2cm gate.

• (1) NAND
• (2) OR
• (3) NOR
• (4) AND

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 \(g = 10\) m/s\(^2\)):

• (1) \( 100 \sqrt{3} N \)
• (2) \( 200 N \)
• (3) \( 200 \sqrt{3} N \)
• (4) \( 100 N \)

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

• (1) \( 0.5 A \)
• (2) \( 2.5 A \)
• (3) \( 1.5 A \)
• (4) \( 2.0 A \)

A model for a quantized motion of an electron in a uniform magnetic field B states that the flux passing through the orbit of the electron is \( \phi = n h / e \) 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):

• (1) \( \frac{he}{4 \pi m} \)
• (2) \( \frac{he}{2 \pi m} \)
• (3) \( \frac{he}{2 m} \)
• (4) \( \frac{he}{4 m} \)

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

• (1) A and C
• (2) A and D
• (3) B and D
• (4) A only

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 of magnitude \(9 \times 10^{-4}\) T perpendicular to its direction of motion. We wish to apply a uniform electric field \( \vec{E} \) together with the magnetic field so that the electron does not deflect from its path. (speed of light \(c = 3 \times 10^8\) m/s):

• (1) \( \vec{E} \) is perpendicular to \( \vec{B} \) and its magnitude is \( 2.7 \times 10^2 \) V m\(^{-1} \)
• (2) \( \vec{E} \) is parallel to \( \vec{B} \) and its magnitude is \( 2.7 \times 10^2 \) V m\(^{-1} \)
• (3) \( \vec{E} \) is parallel to \( \vec{B} \) and its magnitude is \( 2.7 \times 10^6 \) V m\(^{-1} \)
• (4) \( \vec{E} \) is perpendicular to \( \vec{B} \) and its magnitude is \( 2.7 \times 10^6 \) V m\(^{-1} \)

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 \(g\) as the acceleration due to gravity)

• (1) \( \frac{d^2 y}{dx^2} = \frac{\rho g}{S} y \)
• (2) \( \frac{d^2 y}{dx^2} = \sqrt{\frac{\rho g}{S}} y \)
• (3) \( \frac{d^2 y}{dx^2} = \sqrt{\frac{S}{\rho g}} y \)
• (4) \( \frac{d^2 y}{dx^2} = \frac{S}{\rho g} y \)

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

• (1) \( f \)
• (2) \( \frac{3}{4} f \)
• (3) \( 2f \)
• (4) \( \frac{1}{2} f \)

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:

• (1) constant between the plates and zero outside the plates
• (2) non-zero everywhere with maximum at the imaginary cylindrical surface connecting peripheries of the plates
• (3) zero between the plates and non-zero outside
• (4) zero at all places

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

• (1) \( \frac{11}{9} \)
• (2) \( \frac{7}{5} \)
• (3) \( \frac{5}{3} \)
• (4) \( \frac{3}{2} \)

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 :

• (1) \( 2.0 A \)
• (2) \( 2.5 A \)
• (3) \( 3.0 A \)
• (4) \( 1.5 A \)

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

• (1) \( -2\alpha v^3 \)
• (2) \( 2\beta v^3 \)
• (3) \( -2\beta v^3 \)
• (4) \( -2\alpha \frac{v^3}{(2\alpha x + \beta)^2} \)

Two gases A and B are filled at the same pressure in separate cylinders with movable pistons of radii \(r_A\) and \(r_B\) respectively. On supplying an equal amount of heat to both the cylinders, their pressures remain constant and their pistons are displaced by 16 cm and 9 cm respectively. If the change in their internal energies is the same, then the ratio \(r_A / r_B\) is:

• (1) \( \frac{4}{3} \)
• (2) \( \frac{2}{\sqrt{3}} \)
• (3) \( \frac{\sqrt{3}}{2} \)
• (4) \( \frac{3}{4} \)

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 ω(t) and average amplitude A(t) of the system change with time t. Which one of the following options schematically depicts these changes correctly?

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 :

• (1) \( \frac{7}{40} \)
• (2) \( \frac{7}{57} \)
• (3) \( \frac{7}{64} \)
• (4) \( \frac{7}{8} \)

The plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant \(K_1\) and \(K_2\) with thickness \(d/2\) 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 \(K_1 = 1.25 K_2\), the value of \(K_2\) is :

• (1) \( 2.33 \)
  (2) \( 1.60 \)
  (3) \( 1.33 \)
  (4) \( 2.66 \)

There are two inclined surfaces of equal length inclined at an angle of \(45^\circ\) 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 the rough surface than on the smooth surface. The coefficient of kinetic friction (\(\mu_k\)) between the object and the rough surface is close to :

• (1) \( 0.80 \)
  (2) \( 0.25 \)
  (3) \( 0.75 \)
  (4) \( 0.5 \)

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 :

• (1) \( \left( \frac{1}{2 + 3 \sin \theta} \right)^{1/2} \)
  (2) \( \left( \frac{\cos \theta}{2 + 3 \sin \theta} \right)^{1/2} \)
  (3) \( \left( \frac{\sin \theta}{2 + 3 \sin \theta} \right)^{1/2} \)
  (4) \( (\sin \theta)^{1/2} \)

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 \(n_1 = 2\) moles and \(n_2 = 3\) 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 :

• (1) \( 1.6 atm \)
  (2) \( 1.4 atm \)
  (3) \( 1.8 atm \)
  (4) \( 1.3 atm \)

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 :

• (1) \( 7.8 A and 45^\circ \)
  (2) \( 15.6 A and 20^\circ \)
  (3) \( 15.6 A and 45^\circ \)
  (4) \( 7.8 A and 30^\circ \)

The radius of Martian orbit around the Sun is about 1.5 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?

• (1) \( 225 Earth days \)
  (2) \( 172 Earth days \)
  (3) \( 124 Earth days \)
  (4) \( 88 Earth days \)

A balloon is made of a material of surface tension S and has a small outlet. It is filled with air of density \( \rho \). Initially the balloon is a sphere of radius R. When the gas is allowed to flow out slowly at a constant rate, its radius shrinks as \( r(t) \). Assume that the pressure inside the balloon is \( P(r) \) and is more than the outside pressure (\( P_0 \)) by an amount proportional to the surface tension and inversely proportional to the radius. The balloon bursts when its radius reaches \( r_0 \). Then the speed of gas coming out of the balloon at \( r = R \) is :

• (1) \( \sqrt{\frac{S}{\rho R}} \)
  (2) \( \sqrt{\frac{2S}{\rho R}} \)
  (3) \( \sqrt{\frac{4S}{\rho R}} \)
  (4) \( \sqrt{\frac{S}{2\rho R}} \)

A particle of mass \(m\) is moving around the origin with a constant speed \(v\) along a circular path of radius \(R\). When the particle is at \( (0, R) \), its velocity is \( \mathbf{v} = -v \hat{\mathbf{i}} \). The angular momentum of the particle with respect to the origin is :

• (1) \( mvR \hat{\mathbf{k}} \)
  (2) \( -mvR \hat{\mathbf{k}} \)
  (3) \( mvR \hat{\mathbf{j}} \)
  (4) \( -mvR \hat{\mathbf{j}} \)

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 velocities are the same, the ratio of the amplitude of P to the amplitude of Q is :

• (1) \( \sqrt{\frac{k_2}{k_1}} \)
  (2) \( \sqrt{\frac{k_1}{k_2}} \)
  (3) \( \frac{k_2}{k_1} \)
  (4) \( \frac{k_1}{k_2} \)

A ball of mass 0.5 kg is dropped from a height of 10 m. The ball hits the ground and rises to a height of 1.5 m. The impulse imparted to the ball during its collision with the ground is : (Take \(g = 9.8 \, m/s^2\))

• (1) \( 7 Ns \)
  (2) \( 0 Ns \)
  (3) \( 7 \sqrt{2} Ns \)
  (4) \( 21 \sqrt{2} Ns \)