NEET 2020 Physics Paper: Phase 1

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

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 $\frac{\pi}{3}$. If instead C is removed from the circuit, the phase difference is again $\frac{\pi}{3}$ between current and voltage. The power factor of the circuit is:

For which one of the following, Bohr model is not valid?

The capacitance of a parallel plate capacitor with air as medium is 6$\mu$F. With the introduction of a dielectric medium, the capacitance becomes 30 $\mu$F. The permittivity of the medium is: $\left(\varepsilon_0 = 8.85 \times 10^{-12}\ C^2 N^{-1} m^{-2}\right)$

Two particles of mass 5 kg and 10 kg respectively are attached to the two ends of a rigid rod of length 1 m with negligible mass.

The centre of mass of the system from the 5 kg particle is nearly at a distance of:

A charged particle having drift velocity 7.5 $\times$ 10-4 ms-1 in an electric field of 3 $\times$ 10-10 Vm-1 has a mobility in m2 V-1s-1 of:

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

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

The color code of a resistance is given below:

The values of resistance and tolerance, respectively, are

A resistance wire connected in the left gap of a metre bridge balances a 10 $\Omega$ resistance in the right gap at a point which divides the bridge wire in the ratio 3:2. If the length of the resistance wire is 1.5 m, then the length of 1 $\Omega$ of the resistance wire is:

An electron is accelerated from rest through a potential difference of V volt. If the de-Broglie wavelength of the electron is 1.227 $\times$ 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?

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 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 short electric dipole has a dipole moment of 16 $\times$ 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 $60^\circ$ with the dipole axis is:

$\left(\frac{1}{4\pi\varepsilon_0} = 9 \times 10^{9}\text{ Nm}^2/\text{C}^2\right)$

A spherical conductor of radius 10 cm has a charge of 3.2 $\times$ 10-7 C distributed uniformly. What is the magnitude of electric field at a point 15 cm from the centre of the sphere?

$\left(\frac{1}{4\pi\varepsilon_0} = 9 \times 10^{9}\text{ N m}^2/\text{C}^2\right)$

In a certain region of space with volume 0.2 m3, the electric potential is found to be 5 V throughout. The magnitude of electric field in this region is:

A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth?

The mean free path for a gas, with molecular diameter d and number density n can be expressed as:

Two bodies of mass 4 kg and 6 kg are tied to the ends of a massless string. The string passes over a pulley which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity (g) is:

An iron rod of susceptibility 599 is subjected to a magnetizing field of 1200 A m-1. The permeability of the material of the rod is:

$\left(\mu_0 = 4\pi \times 10^{-7}\text{ TmA}^{-1}\right)$

A wire of length L, area of cross section A is hanging from a fixed support. The length of the wire changed to L1 when mass M is suspended from its free end. The expression for Young's modulus is:

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/s2)

A long solenoid of 50 cm length having 100 turns carries a current of 2.5 A. The magnetic field at the centre of the solenoid is:

$\left(\mu_0 = 4\pi \times 10^{-7}\, TmA^{-1}\right)$

The energy equivalent of 0.5 g of a substance is:

When a uranium isotope ${}^{235}_{92}U$ is bombarded with a neutron, it generates ${}^{89}_{36}Kr$, three neutrons and:

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

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 $\mu$, then the angle of incidence is nearly equal to:

The Brewster's angle ib for an interface should be:

Find the torque about the origin when a force of 3 $\hat{j}$ N acts on a particle whose position vector is 2 $\hat{k}$ m.

For transistor action, which of the following statements is correct?

For the logic circuit shown, the truth table is:

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

A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is:

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

A cylinder contains hydrogen gas at pressure 249 kPa and temperature 27$^\circ$C

Its density is: (R = 8.3 J mol-1 K-1)

Two cylinders A and B of equal capacity are connected to each other via a stop cock. A contains an ideal gas at standard temperature and pressure. B is completely evacuated. The entire systems is thermally insulated. The stop cock is suddenly opened. The Process is:

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

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 of the significant figures, what is the value of $9.99\text{ m} - 0.0099\text{ m}$?

The energy required to break one bond in DNA is 10-20 J. This value in eV is nearly:

Dimensions of stress are:

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

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:

In Young's double slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes: