NEET 2020 Physics Questions

A screw gauge has least count of 0.01 mm and there are 50 divisions in its circular scale. The pitch of the screw gauge is:

Taking into account the significant figures, what is the value of 9.99 m - 0.0099 m?

Dimensions of stress are:

The torque about the origin when a force 3ĵ N acts on a particle whose position vector is 2k̂ m is:

Two particles of mass 5 kg and 10 kg are attached to the ends of a rigid massless rod of length 1 m. The distance of the centre of mass from the 5 kg particle is nearly:

A ball is thrown vertically downward with a velocity of 20 m/s from the top of a tower. It hits the ground after some time with a velocity of 80 m/s. The height of the tower is (g = 10 m/s$^2$):

The average thermal energy for a mono-atomic gas is: (k_B is the Boltzmann constant and T the absolute temperature)

Dimensions of stress are:

The phase difference between displacement and acceleration of a particle in simple harmonic motion is

The quantities of heat required to raise the temperature of two solid copper spheres of radii r₁ and r₂ (r₁ = 1.5 r₂) through 1 K are in the ratio Q₁ : Q₂ equal to:

In a guitar, two strings A and B of the same material are slightly out of tune and produce beats of frequency 6 Hz. When the tension in B is slightly decreased, the beat frequency increases to 7 Hz. If the frequency of A is 530 Hz, the original frequency of B is:

A charged particle having drift velocity 7.5$\times$10$^{-4}$ m s$^{-1}$ in an electric field of 3$\times$10$^{-10}$ V m$^{-1}$ has a mobility (in m$^{2}$ V$^{-1}$ s$^{-1}$) of:

A resistance wire in the left gap of a metre bridge balances a 10 $\Omega$ resistance in the right gap at a point dividing the wire 3:2. If the wire length is 1.5 m, the length corresponding to 1 $\Omega$ is:

The colour code of a resistance is given (Yellow, Violet, Brown, Gold). The values of resistance and tolerance, respectively, are:

The solids which have the negative temperature coefficient of resistance are:

Which of the following graphs represents the variation of resistivity ($\rho$) with temperature (T) for copper?

The capacitance of a parallel plate capacitor with air as medium is 6 microF. With the introduction of a dielectric medium, the capacitance becomes 30 microF. The permittivity of the medium is: (eps0 = 8.85 × 10⁻¹² C² N⁻¹ m⁻²)

A short electric dipole has a dipole moment of 16 × 10⁻⁹ Cm. The electric potential due to the dipole at a point at a distance of 0.6 m from the centre of the dipole, situated on a line making an angle of 60 degrees with the dipole axis is: (1/4*π*eps0 = 9 × 10⁹ N M² / C²)

The solids which have the negative temperature coefficient of resistance are:

The increase in the width of the depletion region in a p-n junction diode is due to:

Assume that light of wavelength 600 nm is coming from a star. The limit of resolution of telescope whose objective has a diameter of 2 m is

The Brewster's angle i_B for an interface should be

Light with an average flux of 20 W/cm² falls on a non-reflecting surface at normal incidence having surface area 20 cm². The energy received by the surface during a time span of 1 minute is

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is (c = speed of electromagnetic waves)

A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is π/3. If instead C is removed from the circuit, the phase difference is again π/3 between current and voltage. The power factor of the circuit is

A 40 μF capacitor is connected to a 200 V, 50 Hz ac supply. The rms value of the current in the circuit is, nearly:

An electron is accelerated from rest through a potential difference of V volt. If the de Broglie wavelength of the electron is 1.227 × 10⁻² nm, the potential difference is:

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled?

A long solenoid of 50 cm length having 100 turns carries a current 2.5 A. The magnetic field at the centre of the solenoid is (μ₀ = 4π × 10⁻⁷ T m A⁻¹)

A ray is incident at an angle of incidence i on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is µ, then the angle of incidence i is nearly equal to

An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 A m⁻¹. The permeability of the material of the rod is (μ₀ = 4π × 10⁻⁷ T m A⁻¹):