List of top Physics Questions asked in NEET (UG)

In a diffraction pattern due to a single slit of width 'a', the first minimum is observed at an angle $30^{\circ}$ when light of wavelength $5000 \mathring A $ is incident on the slit. The first secondary maximum is observed at an angle of :

Given the value of Rydberg constant is $10^7 \, m^{-1}$, the wave number of the last line of the Balmer series in hydrogen spectrum will be :

From a disc of radius R and mass M, a circular hole of diameter R, whose rim passes through the centre is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis, passing through the centre ?

Coefficient of linear expansion of brass and steel rods are $\alpha_1$ and $\alpha_2$. Lengths of brass and steel rods are $ l_1$ and $l_2$ respectively. If $(l_2 - l_1)$ is maintained same at all temperatures, which one of the following relations holds good ?

At what height from the surface of earth the gravitation potential and the value of g are $- 5.4 \times 10^7 \, J \, kg^{-2}$ and $6.0 \, ms^{-2}$ respectively ? Take the radius of earth as $6400 \,km$ :

An inductor $20\, mH$, a capacitor $50\, \mu F$ and a resistor $40 \, \Omega $ are connected in series across a source of emf $V = 10 \, \sin \, 340\,t$. The power loss in A.C. circuit is :

An electron is moving in a circular path under the influence of a transverse magnetic field of $3.57 \times 10^{-2} T$. If the value of $e / m$ is $1.76 \times 10^{11} C / kg$, the frequency of revolution of the electron is

An astronomical telescope has objective and eyepiece of focal lengths $40\, cm$ and $4 \,cm$ respectively. To view an object $200\, cm$ away from the objective, the lenses must be separated by a distance :

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is $50\,cm$. The next larger length of the column resonating with the same tuning fork is :

An air bubble in a glass slab with refractive index $1.5$ (near normal incidence) is $5\,cm$ deep when viewed from one surface and $3\,cm$ deep when viewed from the opposite face. The thickness (in cm) of the slab is

A uniform magnetic field is restricted within a region of radius $r$. The magnetic field changes with time at a rate $\frac{d \vec{B}}{dt}$. Loop $1$ of radius $R > r$ enclosed the region $r$ and loop $2$ of radius $R$ is outside the region of magnetic field as shown in the figure below. Then the e.m.f. generated is

A uniform circular disc of radius 50 cm at rest is free to turn about an axis which is perpendicular to its plane and passes through its centre. It is subjected to a torque which produces a constant angular acceleration of $2.0 \, rad \, s^{-2}$. Its net acceleration in $ms^{-2}$ at the end of 2.0 s is approximately :

A siren emitting a sound of frequency $800\, Hz$ moves away from an observer towards a cliff at a speed of $15\,m\,s^{-1}$. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is : (Take velocity of sound in air = $330 \, ms^{-1}$)

A refrigerator works between $4^{\circ}C$ and $30^{\circ}C$. It is required to remove $600\, calories$ of heat every second in order to keep the temperature of the refrigerated space constant. The power required is : $(Take\, 1 \,cal\, =\, 4.2 \,Joules)$

A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of h is : [Latent heat of ice is $3.4 \times 10^5 \, J/kg$ and $g = 10 \, N/kg$]

A person can see clearly objects only when they lie between $50\,cm$ and $400\,cm$ from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be

A particle of mass $10\,g$ moves along a circle of radius $6.4\,cm$ with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to $8 \times 10^{-4} \, J$ by the end of the second revolution after the beginning of the motion ?

A parallel-plate capacitor of area $A$, plate separation d and capacitance $C$ is filled with four dielectric materials having dielectric constants $k_1, k_2, k_3 $ and $ k_4$ as shown in the figure below. If a single dielectric material is to be used to have the same capacitance $C$ in this capacitor, then its dielectric constant $k$ is given by

A long straight wire of radius a carries a steady current I. The current uniformly distributed over its cross-section. The ratio of the magnetic fields B and B', at radial distance $\frac{a}{2}$ and 2a respectively, from the axis of the wire is :

A linear aperture whose width is $0.02\, cm$ is placed immediately in front of a lens of focal length $60\, cm$. The aperture is illuminated normally by a parallel beam of wavelength $5 \times 10^{-5} cm$. The distance of the first dark band of the diffraction pattern from the centre of the screen is

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then :

A filament bulb $(500\, W, 100 \,V)$ is to be used in $230\, V$ main supply. When a resistance $R$ is connected in series, it works perfectly and the bulb consumes $500\, W$. The value of $R$ is

A disk and a sphere of same radius but different masses roll off on two inclined planes of the same altitude and length. Which one of the two objects gets to the bottom of the plane first ?

A car is negotiating a curved road of radius R. The road is banked at an angle $\theta$. The coefficient of friction between the types of the car and the road is $\mu_s$. The maximum safe velocity on this road is :

A body of mass $m$ is attached to the lower end of a spring whose upper end is fixed. The spring has negligible mass when the mass $m$ is slightly pulled down and released, it oscillates with a time period of $3\,s$. When the mass $m$ is increased by $1\,kg$, the time period of oscillations becomes $5\, s$. The value of $m$ in $kg$ is