Q JEE MAIN 2026

The de Broglie wavelength associated with an electron accelerated through a potential difference V is $\lambda_{\mathrm{e}}$ and the de Broglie...

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In Rutherford's alpha-particle scattering experiment, only a few alpha particles rebound back because A. The size of gold nucleus is...

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$K_1$ and $K_2$ be the maximum kinetic energies of photoelectrons emitted from a surface of a given material for the...

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A monochromatic source of light operating at 15 kW emits $2.5 \times 10^{22}$ photons $/ \mathrm{s}$. The region of an...

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The de Broglie wavelength for an electron accelerated through the potential difference of $V_1$ volt is $\lambda_1$. When the potential...

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The ratio of momentum of the photons of the $1^{\text {st }}$ and $2^{\text {nd }}$ line of Balmer series...

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An electron is travelling with a velocity $v$ in free space and when it enters a medium, its velocity is...

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Light source having wavelength 331 nm is used to generate photo-electrons whose stopping potential is 0.2 V . The work...

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In the hydrogen atom, the electron makes a transition from the higher orbit (i) to a lower orbit (f). The...

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An electron of mass m is moving in an electric field $\vec{E}=-2 E_{\mathrm{o}} \hat{i}\left(\mathrm{E}_0=\right.$ constant $\left.>0\right)$, with an initial velocity...

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The graph shows variation of stopping potential $V_0$ with the frequency $v$ of the incident radiation for three photosensitive metals...

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Using Bohr's model, calculate the ratio of the magnetic fields generated due to the motion of the electrons in the...

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Angular momentum of an electron in a hydrogen atom is $\frac{3 h}{\pi}$, then the energy of the electron is $\_\_\_\_$...

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For a certain metal, when monochromatic light of wavelength $\lambda$ is incident, the stopping potential for photoelectrons is $3 \mathrm{~V}_0$....

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A star has $100 \%$ helium composition. It starts to convert three ${ }^4 \mathrm{He}$ into one ${ }^{12} \mathrm{C}$...

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The energy equivalent of 1 g of substance is

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Conductivity of a photodiode starts changing only if the wavelength of incident light is less than . The band gap...

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The ratio of de Broglie wavelength of a deutron with kinetic energy $E$ to that of an alpha particle with...

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When a light of a given wavelength falls on a metallic surface the stopping potential for photoelectrons is 3.2 V...

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In hydrogen atom spectrum, (R → Rydberg's constant) A. the maximum wavelength of the radiation of Lyman series is $...

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Two electrons are moving in orbits of two hydrogen like atoms with speeds $3 \times 10^5 \mathrm{~m} / \mathrm{s}$ and...

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The average energy released per fission for the nucleus of ${ }_{92}^{235} \mathrm{U}$ is 190 MeV . When all the...

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The de Broglie wavelength of an oxygen molecule at $27^{\circ} \mathrm{C}$ is $x \times 10^{-12} \mathrm{~m}$. The value of $x$...

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Which of the following pair of nuclei are isobars of the element?

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Statement I: Two forces $(\vec{P}+\vec{Q})$ and $(\vec{P}-\vec{Q})$ where $(\vec{P} \perp \vec{Q})$, when act at an angle $\theta_1$ to each other,...

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The smallest wavelength of Lyman series is 91 nm. The difference between the largest wavelengths of Paschen and Balmer series...

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$7.9 \mathrm{MeV} \alpha$-particle scatters from a target material of atomic number 79 . From the given data the estimated diameter...

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A particle having electric charge $3 \times 10^{-19} \mathrm{C}$ and mass $6 \times 10^{-27} \mathrm{~kg}$ is accelerated by applying an...

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If an alpha particle with energy 7.7 MeV is bombarded on a thin gold foil, the closest distance from nucleus...

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A light wave described by $E=60\left[\sin \left(3 \times 10^{15}\right) t+\sin \left(12 \times 10^{15}\right) t\right]$ (in SI units) falls on a...

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The energy of an electron in an orbit of the Bohr's atom is $-0.04 E_0 \mathrm{eV}$ where $\mathrm{E}_0$ is the...

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When radiation of wavelength $\lambda$ is used to illuminate a metallic surface, the stopping potential is V . When the...

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In a reactor, 2 kg of ${ }_{92} \mathrm{U}^{235}$ fuel is fully used up in 30 days. The energy released...

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A particle is moving 5 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle...

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In a hydrogen atom the electron makes a transition from ( $n+1 \alpha_{\sim \sim}^{\text {th }}$ level to the $...

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The pitch and the number of divisions, on the circular scale, for a given screw gauge are 0.5 mm and...

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The magnetic field associated with a light wave is given, at the origin, by $...

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A particle of mass $200 \mathrm{MeV} / \mathrm{c}^2$ collides with a hydrogen atom at rest. Soon after the collision the...

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The electric field of light wave is given as $...

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In a Frank-Hertz experıment, an electron of energy 5.6 eV passes through mercury vapour and emerges with an energy 0.7...

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Consider an electron in a hydrogen atom, revolving in its second excited state (having radius 4.65 Å). The de-Broglie wavelength...

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When a certain photosensistive surface is illuminated with monochromatic light of frequency $v$, the stopping potential for the photo current...

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The electron in a hydrogen atom first jumps from the third excited state to the second excited state and subsequently...

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In a photoelectric effect experiment the threshold wavelength of light is 380 nm . If the wavelength of incident light...

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An electron, a doubly ionized helium ion ( $\mathrm{He}^{++}$) and a proton are having the same kinetic energy. The relation...

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A quantity $f$ is given by $f=\sqrt{\frac{h c^5}{G}}$ where $c$ is speed of light, $G$ universal gravitational constant and $h$...

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Radiation, with wavelength 6561 Å falls on a metal surface to produce photoelectrons. The electrons are made to enter a...

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The surface of a metal is illuminated alternately with photons of energies $E_1=4 \mathrm{eV}$ and $E_2=2.5 \mathrm{eV}$ respectively. The ratio...

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The graph which depicts the results of Rutherford gold foil experiment with $\alpha$-particle is $\theta$ : Scattering angle Y: Number...

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Light is incident normally on a completely absorbing surface with an energy flux of 25 Wcm2. If the surface has...

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When photon of energy 4.0 eV strikes the surface of a metal A , the ejected photoelectrons have maximum kinetic...

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A 2 mW laser operates at a wavelength of 500 nm . The number of photons that will be emitted...

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In $\mathrm{Li}^{++}$, electron in first Bohr orbit is excited to a level by a radiation of wavelength $\lambda$. When the...

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In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used....

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A particle moving with kinetic energy E has de Broglie wavelength $\lambda$. If energy $\Delta \mathrm{E}$ is added to its...

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In the line spectra of hydrogen atom, difference between the largest and the shortest wavelengths of the Lyman series is...

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Given figure shows few data points in a photo electric effect experiment for a certain metal. The minimum energy for...

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Particle $A$ of mass $m_A=\frac{m}{2}$ moving along the $x-$ axis with velocity $\mathrm{v}_0$ collides elastically with another particle $B$ at...

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Taking the wavelength of first Balmer line in hydrogen spectrum (n = 3 to n = 2) as 660 nm,...

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In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the...

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There is a small source of light at some depth below the surface of water (refractive index $=4 / 3$...

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The magnetic field associated with a light wave is given, at the origin, by $...

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A force acts on a 2 kg object so that its position is given as a function of time as...

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The energy required to ionise a hydrogen like ion in its ground state is 9 Rydbergs. What is the Wavelength...

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If a semiconductor photodiode can detect a photon with a maximum wavelength of 400 nm, then its band gap energy...

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An electron of mass m and magnitude of charge |e| initially at rest gets accelerated by a constant electric field...

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The first member of the Balmer series of hydrogen atom has a wavelength of 6561 Å. The wavelength of the...

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An electron (mass $m$ ) with initial velocity $\vec{v}=v_0 \hat{i}+v_0 \hat{j} \vec{E}=-E_0 \hat{k}$. If $\lambda_0$ is initial de-Broglie wavelength of...

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Q JEE-MAIN 2020

Hydrogen ion and singly ionized helium atom are accelerated, from rest, through the same potential difference. The ratio of final...

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Two sources of light emit X-rays of wavelength 1 nm and visible light of wavelength 500 nm, respectively. Both the...

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A particle ' P ' is formed due to a completely inelastic collision of particles ' x ' and '...

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A beam of electromagnetic radiation of intensity $6.4 \times 10^{-5} \mathrm{~W} / \mathrm{cm}^2$ is comprised of wavelength, $\lambda=$ 310 nm...

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Q JEE MAIN 2019

$\mathrm{A} \mathrm{He}^{+}$ion is in its first excited state. Its ionization energy is :

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The time period of revolution of electron in its ground state orbit in a hydrogen atom is $1.6 \times 10^{-16}$...

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Q JEE MAIN 2019

$50 \mathrm{~W} / \mathrm{m}^2$ energy density of sunlight is normally incident on the surface of a solar panel. Some part...

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A metal plate of area $1 \times 10^{-4} \mathrm{~m}^2$ is illuminated by a radiation of intensity $...

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A moving proton and electron have the same de- Broglie wavelength. If K and P denote the K.E. and momentum...

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Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases...

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Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases...

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A free electron of 2.6 eV energy collides with a $\mathrm{H}_{+}$ion. This results in the formation of a hydrogen atom...

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A free electron of 2.6 eV energy collides with a $\mathrm{H}+$ ion. This results in the formation of a hydrogen...

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X different wavelengths may be observed in the spectrum from a hydrogen sample if the atoms are exited to states...

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A monochromatic neon lamp with wavelength of 670.5 nm illuminates a photo-sensitive material which has a stopping voltage of 0.48...

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An electron of mass me and a proton of mass $m_p= 1836 \mathrm{~m}_{\mathrm{e}}$ are moving with the same speed. The...

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The electric field in a plane electromagnetic wave is given by $$ \overrightarrow{\mathrm{E}}-=200 \cos \left[\left(\frac{0.5 \times 10^3}{\mathrm{~m}}\right) \mathrm{x}-\left(1.5 \times 10^{11}...

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Radiation coming from transitions n = 2 to n = 1 of hydrogen atoms fall on He+ ions in n...

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Two particles move at right angle to each other. Their de Broglie wavelengths are $\lambda_1$ and $\lambda_2$ respectively. The particles...

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The $\mathrm{K}_\alpha$ X-ray of molybdenum has wavelength 0.071 nm. If the energy of a molybdenum atoms with a K electron...

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In a photoelectric experiment ultraviolet light of wavelength 280 nm is used with lithium cathode having work function $\phi=2.5 \mathrm{eV}$....

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A particular hydrogen like ion emits radiation of frequency $2.92 \times 10^{15} \mathrm{~Hz}$ when it makes transition from $n=3$ to...

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The de-Broglie wavelength of a particle having kinetic energy E is $\lambda$. How much extra energy must be given to...

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The average translational kinetic energy of N2 gas molecules at ...........°C becomes equal to the K.E. of an electron accelerated...

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A light beam of wavelength 500 nm is incident on a metal having work function of 1.25 eV , placed...

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When radiation of wavelength $\lambda$ is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8 V...

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Q JEE MAIN 2021

An electron moving with speed v and a photon moving with speed c, have same D-Broglie wavelength. The ratio of...

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An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV....

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A particle of mass 4M at rest disintegrates into two particles of mass M and 3M respectively having non zero...

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What should be the order of arrangement of de-Broglie wavelength of electron ( $\lambda_{\mathrm{e}}$ ), an $\alpha$-particle ( $\lambda_\alpha$ )...

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An electron of mass me and a proton of mass $\mathrm{m}_{\mathrm{p}}$ are accelerated through the same potential difference. The ratio...

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A particle of mass $9.1 \times 10^{-31} \mathrm{~kg}$ travels in a medium with a speed of $10^6 \mathrm{~m} / \mathrm{s}$...

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An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV....

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A radioactive sample has an average life of 30 ms and is decaying. A capacitor of capacitance $200 \mu \mathrm{~F}$...

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In Bohr's atomic model, the electron is assumed to revolve in a circular orbit of radius $0.5 \AA$. If the...

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The radiation corresponding to 32 transition of a hydrogen atom falls on a gold surface to generate photoelectrons. These electrons...

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If ' $f$ ' denotes the ratio of the number of nuclei decayed $\left(N_d\right)$ to the number of nuclei at...

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The average translational kinetic energy of $\mathrm{N}_2$ gas molecules at $\_\_\_\_$ ${ }^{\circ} \mathrm{C}$ becomes equal to the K.E. of...

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A certain metallic surface is illuminated by monochromatic radiation of wavelength $\lambda$. The stopping potential for photoelectric current for this...

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An electron having de- Broglie wavelength $\lambda$ is incident on a target in a X-ray tube. Cut – off wavelength...

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With what speed should a galaxy move outward with respect to earth so that the sodium-D line at wavelength 5890...

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The ranges and heights for two projectiles projected with the same initial velocity at angles $42^{\circ}$ and $48^{\circ}$ with the...

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With reference to the observations in photo-electric effect, identify the correct statements from below: A. The square of maximum velocity...

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The temperature of an ideal gas in 3-dimensions is 300 K . The corresponding de-Broglie wavelength of the electron approximately...

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A galaxy is moving away from the earth at a speed of $286 \mathrm{kms}^{-1}$. The shift in the wavelength of...

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The speed of electrons in a scanning electron microscope is $1 \times 10^7 \mathrm{~ms}^{-1}$. If the protons having the same...

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The decay of a proton to neutron is :

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Two identical photocathodes receive the light of frequencies $f_1$ and $f_2$ respectively. If the velocities of the photo-electrons coming out...

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The atomic hydrogen emits a line spectrum consisting of various series. Which series of hydrogen atomic spectra is lying in...

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Surface of certain metal is first illuminated with light of wavelength $\lambda_1=350 \mathrm{~nm}$ and then, by light of wavelength $...

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The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100...

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If $2.5 \times 10^{-6} \mathrm{~N}$ average force is exerted by a light wave on a non-reflecting surface of $30 \mathrm{~cm}^2$...

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Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom?

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A particle is travelling 4 times as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle...

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A radioactive sample disintegrate via two independent decay processes having half lives $T_{1 / 2}^{(1)}$ and $T_{1 / 2}^{(2)}$ respectively....

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Imagine that the electron in a hydrogen atom is replaced by a muon $(\mu)$. The mass of muon particle is...

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An electron of mass m and a photon have same energy E. The ratio of wavelength of electron to that...

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If an electron is moving in the $n^{\text {th }}$ orbit of the hydrogen atom, then its velocity $\left(\mathrm{v}_n\right)$ for...

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The wavelength of an X-ray beam is $10 \A$. The mass of a fictitious particle having the same energy as...

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A monoatomic gas of mass 4.0 u is kept in an insulated container. Container is moving with velocity $...

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The first three spectral lines of H -atom in the Balmer series are given $\lambda_1, \lambda_2, \lambda_3$ considering the Bohr...

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The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491 nm is 0.710 V....

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The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation :

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Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on...

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The wavelength of the photon emitted by a hydrogen atom when an electron makes a transition from n = 2...

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The recoil speed of a hydrogen atom after it emits a photon in going from $n=5$ state to $n=1$ state...

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Given below are two statements : Statement I : An electric dipole is placed at the centre of a hollow...

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In the given figure, the energy levels of hydrogen atom have been shown along with some transitions marked A, B,...

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Given below are two statements : Statement-I : Two photons having equal linear momenta have equal wavelengths. Statement-II : If...

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If $\lambda_1$ and $\lambda_2$are the wavelengths of the third member of Lyman and first member of the Paschen series respectively,...

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Two radioactive substances $X$ and $Y$ originally have $N_1$ and $N_2$ nuclei respectively. Half life of $X$ is half of...

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Match List - I with List - II. Choose the correct answer from the options given below :

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Match List – I with List – II List – I (a) h (Planck's constant) (b) E (kinetic energy) (c)...

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According to Bohr atom model, in which of the following transitions will the frequency be maximum ?

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An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be:

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An $\alpha$ particle and a proton are accelerated from rest by a potential difference of 200 V . After this,...

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The de Broglie wavelength of a proton and a-particle are equal. The ratio of their velocities is :

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Let $K_1$ and $K_2$ be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength $\lambda_1$ and...

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$\frac{x}{x+4}$ is the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its...

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Hydrogen atom from excited state comes to the ground by emitting a photon of wavelength $\lambda$. The value of principal...

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Two streams of photons, possessing energies to five and ten times the work function of metal are incident on the...

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Sun light falls normally on a surface of area $36 \mathrm{~cm}^2$ and exerts an average force of $...

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The equation $\lambda=\frac{1.227}{\mathrm{x}} \mathrm{nm}$ can be used to find the de-Brogli wavelength of an electron. In this equation x stands...

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In a hydrogen spectrum, $\lambda$ be the wavelength of first transition line of Lyman series. The wavelength difference will be...

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Find the ratio of energies of photons produced due to transition of an election of hydrogen atoms from its (i)...

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The kinetic energy of emitted electron is E when the light incident on the metal has wavelength $\lambda$. To double...

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29. The energy band gap of semiconducting material to produce violet (wavelength = 4000 Å) LED is _____ eV. (Round...

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What is the half-life period of a radioactive material if its activity drops to $1 / 16^{\text {th }}$ of...

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An electron (mass $m$ ) with an initial velocity $\vec{v}=v_0 \hat{i}\left(v_0>0\right)$ is moving in an electric field $\vec{E}=-E_0 \hat{i}\left(E_0>0\right)$ where...

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The magnetic moment of an electron (e) revolving in an orbit around nucleus with an orbital angular momentum is given...

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The momentum of an electron revolving in $\mathrm{n}^{\text {th }}$ orbit is given by :

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A metal exposed to light of wavelength 800 nm and emits photoelectrons with a certain kinetic energy. The maximum kinetic...

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The ratio of wavelengths of proton and deuteron accelerated by potential $V_p$ and $V_d$ is $1: \sqrt{2}$. Then, the ratio...

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A parallel beam of light of wavelength 900 nm and intensity 100 $\mathrm{Wm}^{-2}$ is incident on a surface perpendicular to...

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The half life of a radioactive substance is 5 years. After x years a given sample of the radioactive substance...

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Given below are two statements: Statement I : In hydrogen atom, the frequency of radiation emitted when an electron jumps...

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The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength $6630 \AA$ is 0.42 V ....

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The electric field at the point associated with a light wave is given by E = 200 $...

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In the following nuclear rection, Mass number of D is 182 and atomic number is 74 . Mass number and...

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A sample contains $10^{-2} \mathrm{~kg}$ each of two substances $A$ and $B$ with half lives 4 s and 8 s...

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Which of the following figure represents the variation of $\ln \left(\frac{R}{R_0}\right)$ with $\ln A$ (If $R=$ radius of a nucleus...

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A metal surface is illuminated by a radiation of wavelength 4500 Å. the ejected photo-electron enters a constant magnetic field...

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Which is the correct ascending order of wavelength?

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In Bohr's atomic model of hydrogen, let K. P and E are the kinetic energy, potential energy and total energy...

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The light of two different frequencies whose photons have energies 3.8 eV and 1.4 eV respectively, illuminate a metallic surface...

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A beam of monochromatic light is used to excite the electron in Li++ from the first orbit to the third...

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A hydrogen atom in is ground state absorbs 10.2 eV of energy. The angular momentum of electron of the hydrogen...

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An $\alpha$ particle and a carbon 12 atom has same kinetic energy K. The ratio of their de-Broglie wavelength $...

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Mach List-I with List – II : Choose the correct answer from the options given below :

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A charged particle moves along circular path in a uniform magnetic field in a cyclotron. The kinetic energy of the...

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When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted election...

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Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R....

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An electron with speed v and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy...

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Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two...

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The de Brogue wavelengths for an electron and a photon are $\lambda_{\mathrm{e}}$ and $\lambda_{\mathrm{p}}$ respectively. For the same kinetic energy...

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Choose the correct option from the following options given below :

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The ratio for the speed of the electron in the 3rd orbit of He+ to the speed of the electron...

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Hydrogen atom is bombarded with electrons accelerated through a potential different of $V$, which causes excitation of hydrogen atoms. If...

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Given below are two statements : Statement I : Most of the mass of the atom and all its positive...

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A nucleus has mass number $A_1$ and volume $V_1$. Another nucleus has mass number $A_2$ and volume $V_2$. If relation...

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A particular hydrogen - like ion emits the radiation of frequency $3 \times 10^{15} \mathrm{~Hz}$ when it makes transition from...

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If Rydberg's constant is R, the longest wavelength of radiation in Paschen series will be $\frac{\alpha}{7 \mathrm{R}}$, where α=

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The electric potential at the surface of an atomic nucleus (z=50) of radius $9 \times 10^{-13} \mathrm{~cm}$ is $...

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Two particles $X$ and $Y$ having equal charges are being accelerated through the same potential difference. Thereafter they enter normally...

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The mass number of nucleus having radius equal to half of the radius of nucleus with mass number 192

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Monochromatic light of frequency $6 \times 10^{14}$ Hz is produced by a laser. The power emitted is $...

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In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the...

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A point source is emitting sound waves of intensity $16 \times 10^{-8} \mathrm{Wm}^{-2}$ at the origin. The difference in intensity...

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Two sources of light emit with a power of 200" " W. The ratio of number of photons of visible...

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An object is placed in a medium of refractive index 3 . An electromagnetic wave of intensity $...

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The threshold frequency of a metal with work function 6.63eV is :

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The atomic mass of ${ }_6 \mathrm{C}^{12}$ is 12.000000 u and that of ${ }_6 \mathrm{C}^{13}$ is 13.003354 u ....

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For the photoelectric effect, the maximum kinetic energy $\left(E_k\right)$ of the photoelectrons is plotted against the frequency (v) of the...

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A small particle of mass $m$ moves in such a way that its potential energy $U=\frac{1}{2} m \omega^2 r^2$ where...

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An electron in the hydrogen atom initially in the fourth excited state makes a transition to $n^{\text {th }}$ energy...

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An electron is released from rest near an infinite non-conducting sheet of uniform charge density ' $-\sigma$. The rate of...

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Assume that protons and neutrons have equal masses. Mass of a nucleon is $1.6 \times 10^{-27} \mathrm{~kg}$ and radius of...

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The work functions of Aluminium and Gold are 4.1 eV and 5.1 eV respectively. The ratio of the slope of...

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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason Assertion A...

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Given below are two statements : Statement (I): The dimensions of Planck's constant and angular momentum are same. Statement (II)...

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A photo-emissive substance is illuminated with a radiation of wavelength $\lambda_i$ so that it releases electrons with de-Broglie wavelength $\lambda_e$....

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If 917 Å be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be ____...

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An atom absorbs a photon of wavelength 500 nm and emits another photon of wavelength 600 nm. The net energy...

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Given below are two statements one is labelled as Assertion A and the other is labelled as Reason R. Assertion...

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Given below are two statements: Statement I : Out of microwaves, infrared rays and ultraviolet rays, ultraviolet rays are the...

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Two identical cells each of emf 1.5 V are connected in series across a $10 \Omega$ resistance. An ideal voltmeter...

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A nucleus disintegrates into two nuclear parts, in such a way that ratio of their nuclear sizes is $...

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When vector is subtracted from vector B, it gives a vector equal to 2 . Then the magnitude of vector...

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The variation of stopping potential (V0) as a function of the frequency (v) of the incident light for a metal...

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The energy of He+ ion in its first excited state is. (The ground state energy for the Hydrogen atom is...

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The ratio of the de-Broglie wavelengths of proton and electron having same kinetic energy: (Assume mp = me × 1849)

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In photo electric effect A. The photocurrent is proportional to the intensity of the incident radiation. B. Maximum Kinetic energy...

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The waves emitted when a metal target is bombarded with high energy electrons are

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Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R...

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Given below are two statements : Statement I : Stopping potential in photoelectric effect does not depend on the power...

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Consider the following radioactive decay process The mass number and the atomic number A6 are given by :

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From the photoelectric effect experiment, following observations are made. Identify which of these are correct A. The stopping potential depends...

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If the binding energy of ground state electron in a hydrogen atom is 13.6 eV , then, the energy required...

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Nucleus a having $Z=17$ and equal number of protons and neutrons has 1.2 MeV binding energy per nucleon. Another nucleus...

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The radius of electron's second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be

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Match List–I with List–II Choose the correct answer from the option given below:

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The threshold frequency of metal is $f_0$. When the light of frequency $2 f_0$ is incident on the metal plate,...

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If the two metals $A$ and $B$ are exposed to radiation of wavelength 350 nm . The work functions of...

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A photon is emitted in transition from n = 4 to n = 1 level in hydrogen atom. The corresponding...

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An electron of a hydrogen like atom, having $Z=4$, jumps from $4^{\text {th }}$ energy state to $2^{\text {nd }}$...

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The ratio of de-Broglie wavelength of an -particle and a proton accelerated from rest by the same potential is $\frac{1}{\sqrt{m}}$,...

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The radius of $2^{\text {nd }}$ orbit of $\mathrm{He}^{+}$of Bohr's model is $\mathrm{r}_1$ and that of fourth orbit of Be...

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${ }_{92}^{238} \mathrm{~A}|\rightarrow|_{90}^{234} \mathrm{~B}+{ }_2^4 \mathrm{D}+\mathrm{Q}$ In the given nuclear reaction, the approximate amount of energy released will be :...

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A common example of alpha decay is The energy released $(Q)$ during the alpha decay of ${ }_{92}^{238} U$ is...

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The decay constant for a radioactive nuclide is 1.5 × 10–5 s–1. Atomic of the substance is 60g mole–1, (NA...

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As per given figure $A, B$ and $C$ are the first, second and third excited energy level of hydrogen atom...

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A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. The number of spectral lines emitted...

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The de Broglie wavelength of a molecule in a gas at room temperature (300 K) is 1. If the temperature...

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The difference between threshold wavelengths for two metal surfaces A and B having work function $\phi_A=9 e \mathrm{~V}$ and $...

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A planet having mass 9 Me and radius $4 \mathrm{Re}_{\mathrm{e}}$, where Me and Re are mass and radius of earth...

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A monochromatic light is incident on a hydrogen sample in ground state. Hydrogen atoms absorb a fraction of light and...

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Two radioactive elements A and B initially have same number of atoms. The half life of A is same as...

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Proton $(P)$ and electron $(e)$ will have same de-Broglie wavelength when the ratio of their momentum is (assume, $\mathrm{m}_{\mathrm{p}}=1849 \mathrm{~m}$...

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A proton and an $\alpha$-particle are accelerated from rest by 2 V and 4 V potentials, respectively. The ratio of...

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The angular momentum for the electron in Bohr’s orbit is L. If the electron is assumed to revolve in second...

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A metallic surface is illuminated with radiation of wavelength $\lambda$, the stopping potential is $V_0$.. If the same surface is...

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The radius of fifth orbit of the Li++ is _____ $\times 10^{-12} \mathrm{~m}$. Take radius of hydrogen atom $=0.51 \AA$

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The de Broglie wavelength of an electron having kinetic energy $E$ is $\lambda$. If the kinetic energy of electron becomes...

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The half-life of a radioactive nucleus is 5 years, The fraction of the original sample that would decay in 15...

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The angular momentum for the electron in Bohr’s orbit is L. If the electron is assumed to revolve in second...

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The energy levels of an hydrogen atom are shown below. The transition corresponding to emission of shortest wavelength is

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The kinetic energy of an electron, $\alpha$-particle and a proton are given as 4K, 2K and K respectively. The de-Broglie...

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In an alpha particle scattering experiment distance of closest approach for the $$ \alpha $$ particle is $...

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A point source of light is placed at the center of curvature of a hemispherical surface. The source emits a...

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The wavelength of the radiation emitted is 0 when an electron jumps from the second excited state to the first...

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A light of energy 12.75 eV is incident on a hydrogen atom in its ground state. The atom absorbs the...

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For hydrogen atom, $\lambda_i$ and $\lambda_2$ are the wavelengths corresponding to the transitions 1 and 2 respectively as shown in...

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The mass of proton, neutron and helium nucleus are respectively 1.0073 u, 1.0087 u and 4.0015u. The binding energy of...

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A sinusoidal carrier voltage is amplitude modulated. The resultant amplitude modulated wave has maximum and minimum amplitude of 120 V...

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A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of $\lambda$ . An...

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The amplitude of $15 \sin (1000 \pi \mathrm{t})$ is modulated by $10 \sin (4 \pi \mathrm{t})$ signal. The amplitude modulated...

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Which of the following frequencies does not belong to FM broadcast.

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The threshold wavelength for photoelectric emission from a material is 5500Ǻ. Photoelectrons will be emitted, when this material is illuminated...

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Speed of an electron in Bohr's $7^{\text {th }}$ orbit for Hydrogen atom is $3.6 \times 10^6 \mathrm{~m} / \mathrm{s}$....

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A small object at rest, absorbs a light pulse of power 20 mWX and duration 300 ns . Assuming speed...

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If a source of electromagnetic radiation having power 15 kW produces $10^{16}$ photons per second, the radiation belongs to a...

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Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV. has a de–Broglie wavelength of...

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When a metal surface is illuminated by light of wavelength λ, the stopping potential is 8" " V. When the...

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Radius of a certain orbit of hydrogen atom is 8.48Å. If energy of electron in this orbit is E/x, then...

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If the wavelength of the first member of Lyman series of hydrogen is λ. The wavelength of the second member...

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In photoelectric experiment energy of 2.48eV irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V....

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Binding energy of a certain nucleus is $18 \times 10^8$ J. How much is the difference between total mass of...

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A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as:

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A proton and an electron are associated with same de-Broglie wavelength. The ratio of their kinetic energies is: (Assume $...

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Average force exerted on a non-reflecting surface at normal incidence is $2.4 \times 10^{-4} \mathrm{~N}$. If $360 \mathrm{~W} / \mathrm{cm}^2$...

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The ratio of the shortest wavelength of Balmer series to the shortest wavelength of Lyman series for hydrogen atom is...

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A hydrogen atom changes its state from $n=3$ to $\mathrm{n}=2$. Due to recoil, the percentage change in the wave length...

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The radius of a nucleus of mass number 64 is 4.8 fermi. Then the mass number of another nucleus having...

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The minimum energy required by a hydrogen atom in ground state to emit radiation in Balmer series is nearly :

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An electron rotates in a circle around a nucleus having positive charge Ze. Correct relation between total energy (E) of...

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Given below are two statements: Statement-I: Figure shows the variation of stopping potential with frequency (v) for the two photosensitive...

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Which figure shows the correct variation of applied potential difference $(V)$ with photoelectric current $(I)$ at two different intensities of...

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The de Broglie wavelengths of a proton and an α particle are λ and 2λ respectively. The ratio of the...

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A electron of hydrogen atom on an excited state is having energy $E_n$ =-0.85eV. The maximum number of allowed transitions...

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If the wavelength of the first member of Lyman series of hydrogen is λ. The wavelength of the second member...

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The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the $...

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The work function of a substance is 3.0eV. The longest wavelength of light that can cause the emission of photoelectrons...

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When a hydrogen atom going from $n=2$ to $n=1$ emits a photon, its recoil speed is $\frac{\mathrm{x}}{5} \mathrm{~m} / \mathrm{s}$....

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The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is 25%...

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An electron with mass ' m ' with an initial velocity $(t=0) \vec{v}=v_{0} \hat{i}\left(v_{0}>0\right)$ enters a magnetic field $\vec{B}=B_{0} \hat{j}$....

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Assuming the validity of Bohr's atomic model for hydrogen like ions the radius of $\mathrm{Li}^{++}$ion in its ground state is...

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The radius of third stationary orbit of electron for Bohr's atom is R. The radius of fourth stationary orbit will...

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In an experiment with photoelectric effect, the stopping potential

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The number of spectral lines emitted by atomic hydrogen that is in the $4^{\text {th }}$ energy level, is

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A small mirror of mass m is suspended by a massless thread of length $l$ . Then the small angle...

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Considering the Bohr model of hydrogen like atoms, the ratio of the radius of 5th orbit of the electron in...

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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion...

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The frequency of revolution of the electron in Bohr's orbit varies with $n$, the principal quantum number as

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The work function of a metal is 3 eV. The color of the visible light that is required to cause...

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The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed at 2 m away...

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The ratio of the power of a light source $S_{1}$ to that the light source $S_{2}$ is $2 S_{1}$ is...

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The energy $E$ and momentum $p$ of a moving body of mass $m$ are related by some equation. Given that...

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In photoelectric effect, the stopping potential $\left(\mathrm{V}_{0}\right) \mathrm{v} / \mathrm{s}$ frequency $(v)$ curve is plotted. (h is the Planck's constant...

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In a hydrogen like ion, the energy difference between the ${2^{{\rm{nd }}}}$ excitation energy state and ground is 108.8 eV...

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For a hydrogen atom, the ratio of the largest wavelength of Lyman series to that of the Balmer series is

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A monochromatic light is incident on a metallic plate having work function $\phi$. An electron, emitted normally to the plate...

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Considering Bohr's atomic model for hydrogen atom: (A) the energy of H atom in ground state is same as energy...

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Given below are two statements : one is labelled as Assertion (A) and the other is labelled. as Reason (R)....

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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)....

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If $\lambda $ and K are de Broglie wavelength and kinetic energy, respectively, of a particle with constant mass. The...

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A proton of mass '${m_P}$' has same energy as that of a photon of wavelength '$\lambda $'. If the proton...

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An electron of mass 'm' with an initial velocity $\overrightarrow {\rm{v}} = {{\rm{v}}_0}\hat i\left( {{{\rm{v}}_0} > 0} \right)$ enters an...

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A sub-atomic particle of mass ${{10}^{{-30}}}~\text{kg}$ is moving with a velocity $2.21\times {{10}^{6}}~\text{m}/\text{s}$. Under the matter wave consideration, the particle...

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In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the...

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A light source of wavelength $\lambda$ illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2...

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An electron projected perpendicular to a uniform magnetic field B moves in a circle. If Bohr's quantization is applicable, then...

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An electron in the ground state of the hydrogen atom has the orbital radius of $5.3 \times {10^{ - 11}}\;{\rm{m}}$...

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Q JEE MAIN 2025

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we...

JEE Main Physics Easy

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