List of top Physics Questions asked in NEET (UG)

The photoelectric threshold wavelength of silver is $3250 \times 10^{-10}m$. The velocity of the electron ejected from a silver surface by ultraviolet light of wavelength $2536 \times 10^{-10} m $ is (Given $ h = 4.14 \times 10^{-15} eVs$ and $c = 3 \times 10^8 \, ms^{-1}$)

The x and y coordinates of the particle at any time are $x = 5t - 2t^2$ and $y = 10t$ respectively, where $x$ and $y$ are in meters and t in seconds. The acceleration of the particle at $t = 2s$ is :

Suppose the charge of a proton and an electron differ slightly. One of them is $- e$, the other is ($e + \Delta e $). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance $d$ (much greater than atomic size) apart is zero, then $\Delta e$ is of the order of [Given mass of hydrogen $m_h = 1.67 \times 10^{-27} \, kg$]

The ratio of resolving powers of an optical microscope for two wavelengths $\lambda_1 = 4000 \mathring A$ and $\lambda_2 = 6000 \mathring A$ is :

Radioactive material $'A'$ has decay constant $' 8 \lambda '$ and material $'B' $ has decay constant $'\lambda'$ Initially they have same number of nuclei. After what time, the ration of number of nuclei of material of material $'B' $ to that $'A'$ will be $\frac{1}{e} ?$

Two Polaroids $P_1 $ and $P_2$ are placed with their axis perpendicular to each other. Unpolarised light $I_0$ is incident on $P_1$. A third polaroid $P_3$ is kept in between $P_1$ and $P_2$ such that is axis makes an angle 45$^{\circ}$ with that of $P_1$ .The intensity of transmitted light through $P_2$ is : -

Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities $\omega_1$ and $\omega_2$ . They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is:-

Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time $t_1$. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time $t_2$. The time taken by her to walk up on the moving escalator will be

A rope of negligible mass is wound round a hollow cylinder of mass $3 \,kg$ and radius $40 \,cm$. If the rope is pulled with a force of $30 \,N$, then the angular acceleration produced in the cylinder is

The de-Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature $T$ (Kelvin) and mass $m$, is :

A thin prism having refracting angle $10^{\circ}$ is made of glass of refractive index $1.42$. This prism is combined with another thin prism of glass of refractive index $1.7$. This combination produces dispersion without deviation. The refracting angle of second prism should be :

The resistance of a wire is ‘R’ ohm. If it is melted and stretched to ‘n’ times its original length, its new resistance will be

A thin prism having refracting angle 10° is made of glass of refractive index 1.42. This prism is combined with another thin prism of glass of refractive index 1.7. This combination produces dispersion without deviation. The refracting angle of second prism should be

A rope is wound around a hollow cylinder of mass 3 kg and radius 40 cm. What is the angular acceleration of the cylinder if the rope is pulled with a force of 30 N?

Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t₁. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time t₂. The time taken by her to walk up on the moving escalator will be

A long solenoid of diameter 0.1 m has 2 × 10⁴ turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05 s. If the resistance of the coil is 10π² Ω, the total charge flowing through the coil during this time is

A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K. If the radius were halved and the temperature doubled, the power radiated in watt would be

In an electromagnetic wave in free space the root mean square value of the electric field is E_rms = 6 V/m. The peak value of the magnetic field is

The ratio of resolving powers of an optical microscope for two wavelengths λ₁ = 4000 Å and λ₂ = 6000 Å is

Consider a drop of rain water having mass 1 g falling from a height of 1 km. It hits the ground with a speed of 50 m/s. Take g constant with a value 10 m/s². The work done by the (i) gravitational force and the (ii) resistive force of air is

The bulk modulus of a spherical object is ‘B’. If it is subjected to uniform pressure ‘p’, the fractional decrease in radius is

If θ₁ and θ₂ be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip θ is given by

Two astronauts are floating in gravitational free space after having lost contact with their spaceship. The two will:

Which one of the following represents forward bias diode?