RE-NEET Questions

An ideal gas is made of polyatomic molecules. Each of the molecules has three translational, three rotational and f number of vibrational modes. If the ratio of heat capacities Cₚ/Cᵥ of the gas is 8/7, then the value of f is:

One main scale division of a Vernier calliper is equal to 1 mm and the number of divisions on the Vernier scale is 10. When both the jaws touch each other, the Vernier scale shifts to the left of zero of the main scale in such a way that 4^{th} Vernier division coincides with a division of the main scale. If this Vernier calliper measures the length of a wire to be 1 cm, the actual length of the wire is:

Three identical p-n junction diodes D₁, D₂ and D₃ are connected across a battery as shown in the figure. If the width of the depletion regions of D₁, D₂ and D₃ are W₁, W₂ and W₃, respectively, then the correct option is:

Consider a spring-mass simple harmonic oscillator in one dimension. The mass of the particle is m kg and the spring constant is k Nm⁻¹. At a given instant, the extension of the spring is x meter and the speed of the particle is v meter/s. On the x - v plane, if the graph of v as a function of x is a circle, then the correct option is:

An electromagnetic wave travelling in a lossless dielectric medium having a dielectric constant, εᵣ=9, has the electric field, Eₓ=E₀sin (kz^{-2}π×10⁶t) Vm⁻¹ where E₀ is the amplitude and k is the wave vector. Among the following options, the incorrect choice is:

A frictionless circular wire of unit radius is fixed on the horizontal plane. Two point particles of unit mass start moving simultaneously from point A (θ = π/2) with identical uniform angular speeds in opposite directions, and meet again at point B (θ = 3π/2). During this time, which of the following figures schematically represent the magnitude of the total linear momentum P of the system, as a function of θ?

In Geiger-Marsden experiment, the number of scattered α-particles N(θ) is plotted as a function of scattering angle θ. Which of the following options represents the correct plot?

Consider three media P, Q and R with refractive indices 1, 1.25, and 1.5, respectively. The medium Q having a thickness of 5 cm is placed between extended media P and R as shown in the figure. An object O is placed at the center of medium Q. If viewed from medium P near the normal direction, the apparent depth of O is h₁. For similar observation from medium R, the apparent depth is h₂. The value of |h₁−h₂|, in cm, is:

Consider that σₛ, k_B, b represent Stefan-Boltzmann constant, Boltzmann constant and Wien’s displacement law constant, respectively. The dimension of σₛk_B²b is :

For sound waves, if the number of nodes for the 5^{th} harmonic of an open-ended pipe is n and that for the 9^{th} harmonic of the same pipe with one of its ends closed is m, the ratio n/m is :

Two infinitely long parallel conducting wires A and B carry currents I and 2I, respectively, in the same direction. The wire A has uniform mass per unit length λ and lies on an insulated floor. The wire B is kept fixed at a height h above the floor. The minimum magnitude of h so that the wire A does not rise from the floor is : [g is the acceleration due to gravity and μ₀ is the permeability of free space.]

An ac voltage V=220 sin(2×10³t) Volt is applied to a series LCR circuit. Then the current amplitude in this circuit is : (Given : L=10 mH, C=25μF, R=100 Ω)

Consider a fixed uniformly charged insulating sphere with radius R and total charge +Q. A point charge -q (q<<Q) with mass m is released from rest at a distance of 3R from the centre of the charged sphere. When the point charge reaches the surface of the sphere, its speed is : (ε₀ is the permittivity of vacuum, neglect gravitational forces).

A beam of light falls on a metal surface such that photo-electrons are generated. If power of the light source starts to decrease linearly with time t, then variation of the photocurrent I and magnitude of the stopping potential |V| with time is best represented by :

Two planets P₁ and P₂ with equal mass have radii R₁ and R₂, respectively, where R₂ = \( \frac{R₁}{2} \). The escape speeds of P₁ and P₂ are v₁ and v₂, respectively. Then \( \frac{v₂}{v₁} \) is:

A unit positive point charge is taken slowly through an infinitesimally thin tube that is inside a charged dielectric tube that is inside a charged dielectric sphere of radius R, having uniform positive charge density ρ, as shown in the figure. The initial and final positions of the charge are marked by A and B at distances 2R and 3R respectively, from the centre of the sphere. In this process, the magnitude of the total work done on the point charge is \( \frac{\rho R^2}{n \varepsilon_0} \). The value of n is (\( \varepsilon_0 \) is the permittivity of vacuum).

One mole of an ideal monatomic gas undergoes a cyclic process as shown in the figure. The total heat supplied to the gas is:

The following table presents the parts of the electromagnetic spectrum and their corresponding major applications.

A car travels on a circular racetrack of radius 50 m, which is banked at an angle θ. If the car travels at a speed 10 m/s, then the wear and tear on its tyres is minimum. Taking the acceleration due to gravity to be 10 m/s², the value of θ is:

Consider a particle moving along a straight line, whose position as a function of time is given by \( s(t) = \alpha t^²⁻ \beta t + \gamma \), where \( \alpha = 1 \) m/s², \( \beta = 6 \) m/s and \( \gamma = 5 \) m. The average speed of the particle, in m/s, from t = 0 to t = 6 is:

A point charge Q is placed inside a cavity within a solid isolated conducting sphere. Consider points A, B and C as shown in the figure, where the magnitudes of the electric fields are Eₐ, E_b and E_c respectively. The points B and C are at the same distance from the center of the solid sphere. The correct option is:

In the measurement of viscosity of liquids using terminal velocity experiment, spherical balls of same radius but having different densities are used. The variation of the terminal velocity (v) with the ratio of density of spherical ball (σ) to density of the liquid (ρ), is best represented by:

A ray of light with wavelength λ is incident on three different photo-electric cells namely 1, 2 and 3. The threshold wavelength of these photo-electric cells are λ₁, λ₂, and λ₃, respectively and the magnitude of stopping potentials of these cells are V₁, V₂ and V₃, respectively. The relation between λ and threshold wavelengths are λ₁ < λ, λ₂ > λ and λ₃ >> λ. The correct option is:

A current I₀ flows through a metallic circular loop of radius r as shown in the figure. Resistance of the segment ABC is half that of ADC. Magnitude of magnetic field at the center O of the loop is:

A particle of mass M moves along a horizontal x axis from x=0 to x=L. The coefficient of kinetic friction varies as a function of x as μₖ(x) = μ₀ - αx, where μ₀, α are constants of appropriate dimensions, so that μₖ(L) = 0. The total work done by the frictional force during the motion is ημ₀MgL, where g is the acceleration due to gravity. The value of η is:

In a solar system, the time-period of revolution of a planet tracing a circular orbit of radius R is proportional to:

A solid sphere A of radius R and mass M is attached at a point to a smaller solid sphere B of radius r < R and mass m < M. Assume that the line joining their centres lies along the horizontal. The moment of inertia of the system calculated about a vertical axis passing through the centre of A is Iₐ and that calculated about a vertical axis passing through the centre of B is Iᵦ. The difference Iₐ - Iᵦ is:

The lens combination as shown in the figure, consists of two lenses, L₁ and L₂, of the focal lengths +10 cm and^{-10} cm, respectively. The position of the image formed is:

An ideal Zener diode with breakdown voltage of^{-3} V is reverse biased with a negative input voltage Vᵢ = -5 V. The magnitude of voltage difference between points B and A is:

Three identical capacitors P, Q and S, each of the capacitance C, are connected to a battery of voltage V, as shown in the figure. If the energy stored in the capacitor P and total energy stored in the system are Uₚ and Uₜ, respectively, then the ratio Uₚ/Uₜ is:

A conducting loop of finite resistance lies on the x-y plane. There is a constant magnetic field in the z direction. The area of the loop varies with time t, as A = A₀(¹⁺ sin t) in appropriate units. The figure that correctly indicates the qualitative behaviour of the power P dissipated in the loop as a function of time is:

Consider two circuits, (A) and (B), each having two resistors. One of them has a positive temperature coefficient of resistance, +α, while the other one has a negative temperature coefficient, -α, as shown in the figure. The current I_A and I_B. At initial temperature, the resistance of the two resistors is R₀. As the temperature is increased, the correct option that describes the variation of current in these circuits is:

Bob B of mass m at rest is hanging vertically from the ceiling via a massless string of length 10 m, as shown in the figure. Point mass A of mass m travelling horizontally with speed 10 ms⁻¹ hits bob B elastically. The bob B rises h meter after the collision. Taking the acceleration due to gravity g = 10 ms⁻² and neglecting the size of the bob, the value of h is:

A cylindrical cork of uniform density floats in a liquid of density ρ₁. If the cork is depressed slightly and released, it oscillates harmonically with time period T. If another liquid of the same cork floats in similar oscillation has time period 2T, then the value of ρ₂/ρ₁ is:

The mean free path of molecules in an ideal gas A is half that of another ideal gas B. The diameter of the spherical molecules of gas A is twice the diameter of the molecules of B. If number densities of the gases A and B are nₐ and n_B, respectively, then the correct option is:

Consider the following nuclear reaction: ²³⁸U → ²³⁴Th + ⁴He. Take masses of ²³⁸U, ²³⁴Th and ⁴He as 238.050 u, 234.043 u and 4.003 u, respectively. The Q value for the reaction, in keV, is: [Given: 1 u = 931.5 MeV c⁻²]

Consider a long solenoid of length l and radius r. If n is the number of turns per unit length and μ₀ is the permeability of free space, the inductance of the solenoid is:

Which of the following measurements require 'index correction'?

The temperature of a metallic sphere of radius R is increased by a small amount ΔT. If the linear coefficient of thermal expansion of the metal is α, the approximate increase in the volume of the sphere is:

A photon and an electron, each of 20 eV energy, move in free space. The ratio of linear momentum of electron pₑ to that of photon p_ph is: (Take speed of light = 3×10⁸ ms⁻¹, charge of electron = -1.6×10⁻¹⁹ C and mass of electron = 9×10⁻³¹ kg)

Consider that an electron is revolving in an excited state of Hydrogen atom with velocity 2.56×10⁵ ms⁻¹. The radius of the orbit is xx×10⁻⁹ m. The value of x is: [Take the mass of electron to be 9×10⁻³¹ kg, charge of electron = 1.6×10⁻¹⁹ C and 1/4πε₀ = 9×10⁹ N m² C⁻²]

Two identical inductors are connected in two different configurations P and Q, where a time varying current I(t) is flowing, as shown in the figure. The induced emf between points a and b for configuration P is Eₚ and that for configuration Q is Eₚ. The ratio Eₚ/Eₚ is : [Neglect the effect of mutual inductance.]

In an adiabatic expansion, the temperature of one mole of an ideal monatomic gas (γ=5/3) decreases from 60K to 50K. The work done by the gas in the process is : (Take the universal gas constant as R=8.3 J mol⁻¹ K⁻¹)

Water flows in a streamline motion through a horizontal pipe of circular cross-section as shown in the figure. The pressure difference of water between P and Q is 15 Nm⁻². The area of cross-section at P and Q are 40 cm² and 20 cm², respectively. The rate of flow of water through the pipe, in cm³s⁻¹, is : [Take density of water=1000 kg m⁻³]

A thin horizontal disc is rotating about a vertical axis passing through its fixed centre O. Its angular momentum is Lₐ and Lᵦ computed about points A and B, respectively, with OB = 2 × OA. The value of Lₐ/Lᵦ is:

Match the species in List I with their geometry in List II.

The amino acid that gives a red-blood colour on treating its sodium fusion extract with sodium nitroprusside is

Given below are two statements: Statement-I: Oxidation of p-nitrotoluene with acidic KMnO₄ gives an acid that is stronger than benzoic acid. Statement-II: Reduction of p-nitrotoluene with Sn/HCl followed by neutralization gives an amine that is more basic than aniline. In light of the above statements, choose the most appropriate answer from the options given below.

The standard electrode potential (E°) for the half-cell reaction Fe³⁺ + e⁻ → Fe²⁺ at 298 K is (Given: E°(Fe³⁺/Fe) = -0.04 V and E°(Fe²⁺/Fe) = -0.44 V at 298 K)

The compound that CANNOT be obtained from the aldol condensation reaction shown below, is