Dual Nature of Radiation

185 questions · Physics · JEE Main

Dual Nature of Radiation

185 questions · Physics · JEE Main

A monochromatic light is incident on a metallic plate having work function $ϕ$ . An electron, emitted normally to the plate from a point A with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial…2025 · 2 Apr · Shift 1 · Q52 · MCQ
An electron with mass ' m ' with an initial velocity $(t = 0) v = v_{0} \hat{i} (v_{0} > 0)$ enters a magnetic field $B = B_{0} \hat{j}$ . If the initial…2025 · 2 Apr · Shift 2 · Q60 · MCQ
The work function of a metal is 3 eV . The color of the visible light that is required to cause emission of photoelectrons is2025 · 3 Apr · Shift 1 · Q55 · MCQ
The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed at 2 m away from it, is2025 · 3 Apr · Shift 1 · Q69 · MCQ
A small mirror of mass $m$ is suspended by a massless thread of length $l$ . Then the small angle through which the thread will be deflected when a short pulse of laser of energy E falls normal on the mirror ( $c =$ speed of light in…2025 · 4 Apr · Shift 1 · Q64 · MCQ
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason $R$ Assertion A : In photoelectric effect, on increasing the intensity of incident light the stopping potential increases. Reason R…2025 · 4 Apr · Shift 1 · Q69 · MCQ
A photoemissive substance is illuminated with a radiation of wavelength $λ_{i}$ so that it releases electrons with de-Broglie wavelength $λ_{e}$ . The longest wavelength of radiation that can emit photoelectron is $λ_{o}$ .…2025 · 7 Apr · Shift 2 · Q52 · MCQ
An electron is released from rest near an infinite non-conducting sheet of uniform charge density ' $- σ$ '. The rate of change of de-Broglie wave length associated with the electron varies inversely as nth power of time. The numerical…2025 · 8 Apr · Shift 2 · Q74 · Numerical
The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of2025 · 22 Jan · Shift 1 · Q57 · MCQ
An electron in the ground state of the hydrogen atom has the orbital radius of $5.3 \times 1 0^{- 11} m$ while that for the electron in third excited state is $8.48 \times 1 0^{- 10} m$ . The ratio of the de Broglie…2025 · 22 Jan · Shift 1 · Q62 · MCQ
A light source of wavelength $λ$ illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2 eV . If the same surface is illuminated by a light source of wavelength $\frac{λ}{2}$ , then the maximum…2025 · 22 Jan · Shift 2 · Q65 · MCQ
A sub-atomic particle of mass $1 0^{- 30} kg$ is moving with a velocity $2.21 \times 1 0^{6} m / s$ . Under the matter wave consideration, the particle will behave closely like $(h = 6.63 \times 1 0^{- 34} J . s)$ …2025 · 23 Jan · Shift 1 · Q54 · MCQ
In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em-wave? (Given $hc = 1242 eVnm$ …2025 · 23 Jan · Shift 2 · Q59 · MCQ
An electron of mass ' m ' with an initial velocity $v = v_{0} \hat{i} (v_{0} > 0)$ enters an electric field $E = - E_{o} \hat{k}$ . If the…2025 · 24 Jan · Shift 1 · Q66 · MCQ
In photoelectric effect, the stopping potential $(V_{0}) v / s$ frequency $(v)$ curve is plotted. ( h is the Planck's constant and $ϕ_{0}$ is work function of metal ) (A) $V_{0} v / s v$ …2025 · 24 Jan · Shift 2 · Q57 · MCQ
The ratio of the power of a light source $S_{1}$ to that the light source $S_{2}$ is $2. S_{1}$ is emitting $2 \times 1 0^{15}$ photons per second at 600 nm . If the wavelength of the source $S_{2}$ is 300 nm , then the number of photons per…2025 · 24 Jan · Shift 2 · Q71 · Numerical
A proton of mass ' $m_{P}$ ' has same energy as that of a photon of wavelength ' $λ$ '. If the proton is moving at non-relativistic speed, then ratio of its de Broglie wavelength to the wavelength of photon is.2025 · 28 Jan · Shift 1 · Q58 · MCQ
Which of the following phenomena cannot be explained by wave theory of light?2025 · 28 Jan · Shift 2 · Q62 · MCQ
If $λ$ and $K$ are de Broglie wavelength and kinetic energy, respectively, of a particle with constant mass. The correct graphical representation for the particle will be :2025 · 29 Jan · Shift 1 · Q51 · MCQ
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Emission of electrons in photoelectric effect can be suppressed by applying a sufficiently negative electron…2025 · 29 Jan · Shift 1 · Q72 · MCQ
In an experiment with photoelectric effect, the stopping potential,2025 · 29 Jan · Shift 2 · Q52 · MCQ
The de Broglie wavelengths of a proton and an $α$ particle are $λ$ and $2 λ$ respectively. The ratio of the velocities of proton and $α$ particle will be :2024 · 1 Feb · Shift 1 · Q72 · MCQ
Monochromatic light of frequency $6 \times 1 0^{14} Hz$ is produced by a laser. The power emitted is $2 \times 1 0^{- 3} W$ . How many photons per second on an average, are emitted by the source ? (Given $h = 6.63 \times 1 0^{- 34} Js$ …2024 · 1 Feb · Shift 2 · Q63 · MCQ
Conductivity of a photodiode starts changing only if the wavelength of incident light is less than $660 nm$ . The band gap of photodiode is found to be $(\frac{X}{8}) eV$ . The value of $X$ is…2024 · 1 Feb · Shift 2 · Q77 · MCQ
Which figure shows the correct variation of applied potential difference (V) with photoelectric current (I) at two different intensities of light $(I_{1} < I_{2})$ of same wavelengths :2024 · 4 Apr · Shift 1 · Q73 · MCQ
Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason R. Assertion A: Number of photons increases with increase in frequency of light. Reason R: Maximum kinetic energy of emitted…2024 · 4 Apr · Shift 2 · Q68 · MCQ
Given below are two statements : Statement I : Figure shows the variation of stopping potential with frequency $(v)$ for the two photosensitive materials $M_{1}$ and $M_{2}$ . The slope gives value of $\frac{h}{e}$ , where $h$ is Planck's… Includes diagram2024 · 5 Apr · Shift 1 · Q72 · MCQ
Which of the following statement is not true about stopping potential $(V_{0})$ ?2024 · 5 Apr · Shift 2 · Q69 · MCQ
Which of the following phenomena does not explain by wave nature of light. A. reflection B. diffraction C. photoelectric effect D. interference E. polarization Choose the most appropriate answer from the options given below:2024 · 6 Apr · Shift 1 · Q70 · MCQ
In photoelectric experiment energy of $2.48 eV$ irradiates a photo sensitive material. The stopping potential was measured to be $0.5 V$ . Work function of the photo sensitive material is :2024 · 6 Apr · Shift 1 · Q72 · MCQ
When UV light of wavelength $300 nm$ is incident on the metal surface having work function $2.13 eV$ , electron emission takes place. The stopping potential is : (Given hc $= 1240 eV nm$ )2024 · 6 Apr · Shift 2 · Q69 · MCQ
In Franck-Hertz experiment, the first dip in the current-voltage graph for hydrogen is observed at $10.2 V$ . The wavelength of light emitted by hydrogen atom when excited to the first excitation level is…2024 · 6 Apr · Shift 2 · Q88 · Numerical
A proton and an electron are associated with same de-Broglie wavelength. The ratio of their kinetic energies is: (Assume h = 6.63 $\times 1 0^{- 34} J s, m_{e} = 9.0 \times 1 0^{- 31} kg$ and $m_{p} = 1836$ …2024 · 8 Apr · Shift 1 · Q76 · MCQ
A proton and an electron have the same de Broglie wavelength. If $K_{p}$ and $K_{e}$ be the kinetic energies of proton and electron respectively, then choose the correct relation :2024 · 8 Apr · Shift 2 · Q76 · MCQ
A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as :2024 · 9 Apr · Shift 1 · Q80 · MCQ
UV light of $4.13 eV$ is incident on a photosensitive metal surface having work function $3.13 eV$ . The maximum kinetic energy of ejected photoelectrons will be:2024 · 9 Apr · Shift 2 · Q69 · MCQ
The threshold frequency of a metal with work function $6.63 eV$ is :2024 · 27 Jan · Shift 2 · Q69 · MCQ
The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is $25%$ of the velocity of light, then the ratio of K.E. of electron and K.E. of photon will be:2024 · 29 Jan · Shift 1 · Q62 · MCQ
Two sources of light emit with a power of $200 W$ . The ratio of number of photons of visible light emitted by each source having wavelengths $300 nm$ and $500 nm$ respectively, will be :2024 · 29 Jan · Shift 2 · Q79 · MCQ
The work function of a substance is $3.0 eV$ . The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately;2024 · 30 Jan · Shift 1 · Q62 · MCQ
For the photoelectric effect, the maximum kinetic energy $(E_{k})$ of the photoelectrons is plotted against the frequency $(v)$ of the incident photons as shown in figure. The slope of the graph gives Includes diagram2024 · 30 Jan · Shift 2 · Q71 · MCQ
If the total energy transferred to a surface in time $t$ is $6.48 \times 1 0^{5} J$ , then the magnitude of the total momentum delivered to this surface for complete absorption will be:2024 · 30 Jan · Shift 2 · Q78 · MCQ
When a metal surface is illuminated by light of wavelength $λ$ , the stopping potential is $8 V$ . When the same surface is illuminated by light of wavelength $3 λ$ , stopping potential is $2 V$ . The threshold…2024 · 31 Jan · Shift 1 · Q69 · MCQ
In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons…2024 · 31 Jan · Shift 2 · Q63 · MCQ
A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of $λ$ . An alpha particle having certain kinetic energy has the same de-Brogle wavelength $λ$ . The ratio of kinetic energy of proton and…2023 · 1 Feb · Shift 1 · Q54 · MCQ
The threshold frequency of a metal is $f_{0}$ . When the light of frequency $2 f_{0}$ is incident on the metal plate, the maximum velocity of photoelectrons is $v_{1}$ . When the frequency of incident radiation is increased to $5 f_{0}$ …2023 · 1 Feb · Shift 2 · Q61 · MCQ
The kinetic energy of an electron, $α$ -particle and a proton are given as $4 K, 2 K$ and $K$ respectively. The de-Broglie wavelength associated with electron $(λ e), α$ -particle $((λ α)$ …2023 · 6 Apr · Shift 1 · Q51 · MCQ
The work functions of Aluminium and Gold are $4.1 eV$ and and $5.1 eV$ respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is2023 · 6 Apr · Shift 2 · Q55 · MCQ
Proton $(P)$ and electron (e) will have same de-Broglie wavelength when the ratio of their momentum is (assume, $m_{p} = 1849 m_{e}$ ):2023 · 8 Apr · Shift 1 · Q64 · MCQ
In photo electric effect A. The photocurrent is proportional to the intensity of the incident radiation B. Maximum Kinetic energy with which photoelectrons are emitted depends on the intensity of incident light. C. Max. K.E with which…2023 · 8 Apr · Shift 2 · Q45 · MCQ
The de Broglie wavelength of a molecule in a gas at room temperature (300 K) is $λ_{1}$ . If the temperature of the gas is increased to 600 K, then the de Broglie wavelength of the same gas molecule becomes2023 · 10 Apr · Shift 1 · Q55 · MCQ
The variation of stopping potential $(V_{0})$ as a function of the frequency $(v)$ of the incident light for a metal is shown in figure. The work function of the surface is Includes diagram2023 · 10 Apr · Shift 2 · Q53 · MCQ
A metallic surface is illuminated with radiation of wavelength $λ$ , the stopping potential is $V_{0}$ . If the same surface is illuminated with radiation of wavelength $2 λ$ . the stopping potential becomes $\frac{V _{o}}{4}$ . The…2023 · 11 Apr · Shift 1 · Q61 · MCQ
A monochromatic light is incident on a hydrogen sample in ground state. Hydrogen atoms absorb a fraction of light and subsequently emit radiation of six different wavelengths. The frequency of incident light is $x \times 1 0^{15} Hz$ …2023 · 11 Apr · Shift 1 · Q75 · Numerical
The ratio of the de-Broglie wavelengths of proton and electron having same Kinetic energy : (Assume $m_{p} = m_{e} \times 1849$ )2023 · 11 Apr · Shift 2 · Q51 · MCQ
A proton and an $α$ -particle are accelerated from rest by $2 V$ and $4 V$ potentials, respectively. The ratio of their de-Broglie wavelength is :2023 · 12 Apr · Shift 1 · Q52 · MCQ
The difference between threshold wavelengths for two metal surfaces $A$ and $B$ having work function $ϕ_{A} = 9 eV$ and $ϕ_{B} = 4 \cdot 5 eV$ in $nm$ is: ${$ Given, hc $= 1242 eV nm}$ …2023 · 13 Apr · Shift 1 · Q50 · MCQ
Given below are two statements: Statement I : Out of microwaves, infrared rays and ultraviolet rays, ultraviolet rays are the most effective for the emission of electrons from a metallic surface. Statement II : Above the threshold…2023 · 13 Apr · Shift 2 · Q58 · MCQ
An atom absorbs a photon of wavelength $500 nm$ and emits another photon of wavelength $600 nm$ . The net energy absorbed by the atom in this process is $n \times 1 0^{- 4} eV$ . The value of n is …2023 · 13 Apr · Shift 2 · Q63 · Numerical
The de Broglie wavelength of an electron having kinetic energy $E$ is $λ$ . If the kinetic energy of electron becomes $\frac{E}{4}$ , then its de-Broglie wavelength will be :2023 · 15 Apr · Shift 1 · Q49 · MCQ
From the photoelectric effect experiment, following observations are made. Identify which of these are correct. A. The stopping potential depends only on the work function of the metal. B. The saturation current increases as the intensity…2023 · 24 Jan · Shift 1 · Q50 · MCQ
An $α$ -particle, a proton and an electron have the same kinetic energy. Which one of the following is correct in case of their de-Broglie wavelength:2023 · 24 Jan · Shift 2 · Q49 · MCQ
Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV, has a de-Broglie wavelength of $λ_{0}$ . IF the voltage is increased to 40 kV, then the de-Broglie wavelength associated with the electron beam would…2023 · 25 Jan · Shift 1 · Q56 · MCQ
Given below are two statements : Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source. Statement II : For a given metal, the maximum kinetic energy of the photoelectron depends on the…2023 · 25 Jan · Shift 2 · Q64 · MCQ
The threshold wavelength for photoelectric emission from a material is 5500 $A o$ . Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a A. 75 W infra-red lamp B. 10 W…2023 · 29 Jan · Shift 1 · Q64 · MCQ
The ratio of de-Broglie wavelength of an $α$ particle and a proton accelerated from rest by the same potential is $\frac{1}{m}$ , the value of m is -2023 · 29 Jan · Shift 2 · Q45 · MCQ
A small object at rest, absorbs a light pulse of power $20 mW$ and duration $300 ns$ . Assuming speed of light as $3 \times 1 0^{8} m / s$ , the momentum of the object becomes equal to :2023 · 30 Jan · Shift 1 · Q42 · MCQ
An electron accelerated through a potential difference $V_{1}$ has a de-Broglie wavelength of $λ$ . When the potential is changed to $V_{2}$ , its de-Broglie wavelength increases by $50%$ . The value of $(\frac{V _{1}}{V _{2}})$ …2023 · 30 Jan · Shift 2 · Q49 · MCQ
If a source of electromagnetic radiation having power $15 kW$ produces $1 0^{16}$ photons per second, the radiation belongs to a part of spectrum is. (Take Planck constant $h = 6 \times 1 0^{- 34} Js$ )2023 · 31 Jan · Shift 1 · Q64 · MCQ
If the two metals $A$ and $B$ are exposed to radiation of wavelength $350 nm$ . The work functions of metals $A$ and $B$ are $4.8 eV$ and $2.2 eV$ . Then choose the correct…2023 · 31 Jan · Shift 2 · Q48 · MCQ
When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1. When the frequency of incident radiation is increased to five times the threshold value, the maximum…2022 · 24 Jun · Shift 1 · Q66 · Numerical
The light of two different frequencies whose photons have energies 3.8 eV and 1.4 eV respectively, illuminate a metallic surface whose work function is 0.6 eV successively. The ratio of maximum speeds of emitted electrons for the two…2022 · 24 Jun · Shift 2 · Q62 · MCQ
A metal exposed to light of wavelength $800 nm$ and and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength $500 nm$ is used. The…2022 · 25 Jul · Shift 1 · Q57 · MCQ
The ratio of wavelengths of proton and deuteron accelerated by potential Vp and Vd is 1 : $2$ . Then the ratio of Vp to Vd will be :2022 · 25 Jul · Shift 2 · Q51 · MCQ
A proton, a neutron, an electron and an $α$ particle have same energy. If $λ$ p, $λ$ n, $λ$ e and $λ$ a are the de Broglie's wavelengths of proton, neutron, electron and $α$ particle respectively, then…2022 · 25 Jun · Shift 2 · Q61 · MCQ
A parallel beam of light of wavelength $900 nm$ and intensity $100 Wm^{- 2}$ is incident on a surface perpendicular to the beam. The number of photons crossing $1 cm^{2}$ area perpendicular to the beam in one…2022 · 26 Jul · Shift 1 · Q47 · MCQ
An electron with speed v and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee and pe and that of photon are Eph and pph respectively. Which of the following is correct?2022 · 26 Jun · Shift 1 · Q57 · MCQ
A metal surface is illuminated by a radiation of wavelength 4500 $A o$ . The ejected photo-electron enters a constant magnetic field of 2 mT making an angle of 90 $^{\circ}$ with the magnetic field. If it starts revolving in a…2022 · 26 Jun · Shift 2 · Q63 · MCQ
The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630 $A o$ is 0.42 V. If the threshold frequency is x $\times$ 1013 /s, where x is (nearest…2022 · 26 Jun · Shift 2 · Q72 · Numerical
An electron (mass $m$ ) with an initial velocity $v = v_{0} \hat{i} (v_{0} > 0)$ is moving in an electric field $E = - E_{0} \hat{i} (E_{0} > 0)$ where $E_{0}$ is constant. If at $t = 0$ de…2022 · 27 Jul · Shift 1 · Q61 · MCQ
With reference to the observations in photo-electric effect, identify the correct statements from below : (A) The square of maximum velocity of photoelectrons varies linearly with frequency of incident light. (B) The value of saturation…2022 · 27 Jul · Shift 2 · Q55 · MCQ
An $α$ particle and a carbon 12 atom has same kinetic energy K. The ratio of their de-Broglie wavelengths $(λ_{α} : λ_{C 12})$ is :2022 · 27 Jun · Shift 1 · Q54 · MCQ
The equation $λ = \frac{1.227}{x} nm$ can be used to find the de-Brogli wavelength of an electron. In this equation $x$ stands for : Where $m =$ mass of electron $P =$ momentum of electron $K =$ …2022 · 28 Jul · Shift 1 · Q62 · MCQ
Two streams of photons, possessing energies equal to five and ten times the work function of metal are incident on the metal surface successively. The ratio of maximum velocities of the photoelectron emitted, in the two cases respectively,…2022 · 28 Jul · Shift 2 · Q56 · MCQ
The de Broglie wavelengths for an electron and a photon are $λ$ e and $λ$ p respectively. For the same kinetic energy of electron and photon, which of the following presents the correct relation between the de Broglie…2022 · 28 Jun · Shift 1 · Q56 · MCQ
Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength $λ$ 1 and $λ$ 2, respectively are incident on a metallic surface. If $λ$ 1 = 3 $λ$ 2 then :2022 · 28 Jun · Shift 2 · Q66 · MCQ
The kinetic energy of emitted electron is E when the light incident on the metal has wavelength $λ$ . To double the kinetic energy, the incident light must have wavelength:2022 · 29 Jul · Shift 1 · Q63 · MCQ
An $α$ particle and a proton are accelerated from rest through the same potential difference. The ratio of linear momenta acquired by above two particles will be:2022 · 29 Jul · Shift 2 · Q53 · MCQ
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : The photoelectric effect does not takes place, if the energy of the incident radiation is less than the work function of…2022 · 29 Jun · Shift 1 · Q47 · MCQ
The electric field at a point associated with a light wave is given by E = 200 [sin (6 $\times$ 1015)t + sin (9 $\times$ 1015)t] Vm $-$ 1 Given : h = 4.14 $\times$ 10 $-$ 15 eVs If this light falls on a metal surface having a work function…2022 · 29 Jun · Shift 2 · Q48 · MCQ
A source of monochromatic light liberates 9 $\times$ 1020 photon per second with wavelength 600 nm when operated at 400 W. The number of photons emitted per second with wavelength of 800 nm by the source of monochromatic light operating at…2022 · 30 Jun · Shift 1 · Q58 · MCQ
The temperature of an ideal gas in 3-dimensions is 300 K. The corresponding de-Broglie wavelength of the electron approximately at 300 K, is : [me = mass of electron = 9 $\times$ 10 $-$ 31 kg, h = Planck constant = 6.6 $\times$ 6.6…2021 · 1 Sep · Shift 2 · Q49 · MCQ
The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation :2021 · 16 Mar · Shift 1 · Q57 · MCQ
The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100 V. What should nearly be the ratio of their wavelengths? (mp = 1.00727u me = 0.00055u)2021 · 16 Mar · Shift 2 · Q53 · MCQ
An electron of mass m and a photon have same energy E. The ratio of wavelength of electron to that of photon is : (c being the velocity of light)2021 · 17 Mar · Shift 1 · Q61 · MCQ
Two identical photocathodes receive the light of frequencies f1 and f2 respectively. If the velocities of the photo-electrons coming out are v1 and v2 respectively, then2021 · 17 Mar · Shift 2 · Q48 · MCQ
A particle is travelling 4 time as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2 : 1, the mass of the particle is :2021 · 18 Mar · Shift 1 · Q54 · MCQ
The radiation corresponding to 3 $\to$ 2 transition of a hydrogen atom falls on a gold surface to generate photoelectrons. The electrons are passed through a magnetic field of 5 $\times$ 10 $-$ 4 T. Assume that the radius of the largest…2021 · 20 Jul · Shift 1 · Q57 · MCQ
An electron having de-Broglie wavelength $λ$ is incident on a target in a X-ray tube. Cut-off wavelength of emitted X-ray is :2021 · 20 Jul · Shift 2 · Q55 · MCQ
A certain metallic surface is illuminated by monochromatic radiation of wavelength $λ$ . The stopping potential for photoelectric current for this radiation is 3V0. If the same surface is illuminated with a radiation of wavelength 2 $λ$ …2021 · 20 Jul · Shift 2 · Q71 · Numerical
An electron of mass me and a proton of mass mp are accelerated through the same potential difference. The ratio of the de-Broglie wavelength associated with the electron to that with the proton is2021 · 22 Jul · Shift 2 · Q60 · MCQ
Given below are two statements : Statement I : Two photons having equal linear momenta have equal wavelengths. Statement II : If the wavelength of photon is decreased, then the momentum and energy of a photon will also decrease. In the…2021 · 24 Feb · Shift 1 · Q71 · MCQ
An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be :2021 · 24 Feb · Shift 2 · Q47 · MCQ
The de-Broglie wavelength of a proton and $α$ -particle are equal. The ratio of their velocities is :2021 · 24 Feb · Shift 2 · Q59 · MCQ
An $α$ particle and a proton are accelerated from rest by a potential difference of 200V. After this, their de Broglie wavelengths are $λ α$ and $λ$ p respectively. The ratio $\frac{λ _{p}}{λ _{α}}$ …2021 · 25 Feb · Shift 1 · Q48 · MCQ
An electron of mass me and a proton of mass mp = 1836 me are moving with the same speed. The ratio of their de Broglie wavelength $\frac{^{λ} e l ec t r o n}{^{λ} p r o t o n}$ will be :2021 · 25 Feb · Shift 2 · Q52 · MCQ
The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491 nm is 0.710 V. When the incident wavelength is changed to a new value, the stopping potential is 1.43 V. The new wavelength…2021 · 25 Feb · Shift 2 · Q67 · MCQ
What should be the order of arrangement of de-Broglie wavelength of electron ( $λ$ e), an $α$ -particle ( $λ$ a) and proton ( $λ$ p) given that all have the same kinetic energy?2021 · 25 Jul · Shift 1 · Q48 · MCQ
A particle of mass 4M at rest disintegrates into two particles of mass M and 3M respectively having non zero velocities. The ratio of de-Broglie wavelength of particle of mass M to that of mass 3M will be :2021 · 25 Jul · Shift 1 · Q50 · MCQ
An electron moving with speed v and a photon moving with speed c, have same D-Broglie wavelength. The ratio of kinetic energy of electron to that of photon is :2021 · 25 Jul · Shift 2 · Q59 · MCQ
When radiation of wavelength $λ$ is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8 V. If the same surface is illuminated by radiation of double the previous wavelength, then the stopping…2021 · 25 Jul · Shift 2 · Q62 · MCQ
A light beam of wavelength 500 nm is incident on a metal having work function of 1.25 eV, placed in a magnetic field of intensity B. The electrons emitted perpendicular to the magnetic field B, with maximum kinetic energy are bent into…2021 · 25 Jul · Shift 2 · Q65 · Numerical
In a photoelectric experiment ultraviolet light of wavelength 280 nm is used with lithium cathode having work function $ϕ$ = 2.5 eV. If the wavelength of incident light is switched to 400 nm, find out the change in the stopping…2021 · 26 Aug · Shift 1 · Q53 · MCQ
The de-Broglie wavelength of a particle having kinetic energy E is $λ$ . How much extra energy must be given to this particle so that the de-Broglie wavelength reduces to 75% of the initial value?2021 · 26 Aug · Shift 2 · Q47 · MCQ
Given below are two statements : one is labeled as Assertion A and the other is labelled as Reason R. Assertion A : An electron microscope can achieve better resolving power than an optical microscope. Reason R : The de Broglie's…2021 · 26 Feb · Shift 1 · Q58 · MCQ
The recoil speed of a hydrogen atom after it emits a photon in going from n = 5 state to n = 1 state will be :2021 · 26 Feb · Shift 2 · Q54 · MCQ
Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The value of ratio of maximum velocities of the photoelectrons emitted in the two respective…2021 · 26 Feb · Shift 2 · Q75 · Numerical
In a photoelectric experiment, increasing the intensity of incident light :2021 · 27 Aug · Shift 1 · Q51 · MCQ
A monochromatic neon lamp with wavelength of 670.5 nm illuminates a photo-sensitive material which has a stopping voltage of 0.48 V. What will be the stopping voltage if the source light is changed with another source of wavelength of…2021 · 27 Aug · Shift 2 · Q51 · MCQ
A particle of mass 9.1 $\times$ 10 $-$ 31 kg travels in a medium with a speed of 106 m/s and a photon of a radiation of linear momentum 10 $-$ 27 kg m/s travels in vacuum. The wavelength of photon is times the…2021 · 27 Jul · Shift 1 · Q69 · Numerical
An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV. The proton captures the electron and forms a hydrogen atom in second excited state. The resulting photon is incident on…2021 · 27 Jul · Shift 2 · Q45 · MCQ
A moving proton and electron have the same de-Broglie wavelength. If K and P denote the K.E. and momentum respectively. Then choose the correct option :2021 · 31 Aug · Shift 1 · Q62 · MCQ
A free electron of 2.6 eV energy collides with a H+ ion. This results in the formation of a hydrogen atom in the first excited state and a photon is released. Find the frequency of the emitted photon. (h = 6.6 $\times$ 10 $-$ 34 Js)2021 · 31 Aug · Shift 2 · Q47 · MCQ
Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of the uncertainty in determining the position of an electron to that of a proton is…2021 · 31 Aug · Shift 2 · Q50 · MCQ
When radiation of wavelength $λ$ is used to illuminate a metallic surface, the stopping potential is V. When the same surface is illuminated with radiation of wavelength 3 $λ$ , the stopping potential is $\frac{V}{4}$ . If the…2020 · 2 Sep · Shift 1 · Q58 · Numerical
A particle is moving 5 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle to that of the electron is 1.878 $\times$ 10–4. The mass of the particle is close to2020 · 2 Sep · Shift 2 · Q49 · MCQ
When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to :2020 · 3 Sep · Shift 1 · Q55 · MCQ
Two sources of light emit X-rays of wavelength 1 nm and visible light of wavelength 500 nm, respectively. Both the sources emit light of the same power 200 W. The ratio of the number density of photons of X-rays to the number density of…2020 · 3 Sep · Shift 2 · Q61 · MCQ
Given figure shows few data points in a phot electric effect experiment for a certain metal. The minimum energy for ejection of electron from its surface is: (Plancks constant h = 6.62 × 10–34 J.s) Includes diagram2020 · 4 Sep · Shift 1 · Q43 · MCQ
Particle A of mass mA = $\frac{m}{2}$ moving along the x-axis with velocity v0 collides elastically with another particle B at rest having mass mB = $\frac{m}{3}$ . If both particles move along the x-axis after the collision, the change $Δ λ$ …2020 · 4 Sep · Shift 1 · Q51 · MCQ
In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased : Includes diagram2020 · 4 Sep · Shift 2 · Q46 · MCQ
The surface of a metal is illuminated alternately with photons of energies E1 = 4 eV and E2 = 2.5 eV respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is 2. The work function of the metal in (eV) is …2020 · 5 Sep · Shift 2 · Q55 · Numerical
An electron, a doubly ionized helium ion (He++) and a proton are having the same kinetic energy. The relation between their respective de-Broglie wavelengths $λ$ e, $λ$ He++ and $λ$ p is :2020 · 6 Sep · Shift 1 · Q57 · MCQ
Assuming the nitrogen molecule is moving with r.m.s. velocity at 400 K, the de-Broglie wavelength of nitrogen molecule is close to : (Given : nitrogen molecule weight : 4.64 $\times$ 10–26 kg, Boltzman constant: 1.38 $\times$ 10–23 J/K,…2020 · 6 Sep · Shift 2 · Q36 · MCQ
A beam of electromagnetic radiation of intensity 6.4 × 10–5 W/cm2 is comprised of wavelength, $λ$ = 310 nm. It falls normally on a metal (work function $ϕ$ = 2eV) of surface area of 1 cm2. If one in 103 photons ejects an elctron,…2020 · 7 Jan · Shift 1 · Q44 · Numerical
An electron (of mass m) and a photon have the same energy E in the range of a few eV. The ratio of the de-Broglie wavelength associated with the electron and the wavelength of the photon is (c = speed of light in vaccuum)2020 · 7 Jan · Shift 2 · Q58 · MCQ
When photon of energy 4.0 eV strikes the surface of a metal A, the ejected photoelectrons have maximum kinetic energy TA eV end de-Broglie wavelength $λ_{A}$ . The maximum kinetic energy of photoelectrons liberated from another metal B…2020 · 8 Jan · Shift 1 · Q41 · MCQ
An electron (mass m) with initial velocity $v = v_{0} i + v_{0} j$ is in an electric field $E = - E_{0} k$ . If $λ_{0}$ is initial de-Broglie wavelength of electron, its…2020 · 8 Jan · Shift 2 · Q41 · MCQ
A particle moving with kinetic energy E has de Broglie wavelength $λ$ . If energy $Δ$ E is added to its energy, the wavelength become $λ$ /2. Value of $Δ$ E, is :2020 · 9 Jan · Shift 1 · Q58 · MCQ
Radiation, with wavelength 6561 $A o$ falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of 3 × 10–4 T. If the radius of the largest circular path followed by the…2020 · 9 Jan · Shift 1 · Q64 · MCQ
An electron of mass m and magnitude of charge |e| initially at rest gets accelerated by a constant electric field E. The rate of change of de-Broglie wavelength of this electron at time t ignoring relativistic effects is :2020 · 9 Jan · Shift 2 · Q46 · MCQ
Two particles move at right angle to each other. Their de-Broglie wavelengths are $λ_{1}$ and $λ_{2}$ respectively. The particles suffer perfectly inelastic collision. The de-Broglie wavelength $λ_{2}$ of the final particle,…2019 · 8 Apr · Shift 1 · Q48 · MCQ
A nucleus A, with a finite de-broglie wavelength $λ$ A, undergoes spontaneous fission into two nuclei B and C of equal mass. B flies in the same direction as that of A, while C flies in the opposite direction with a velocity equal to…2019 · 8 Apr · Shift 2 · Q55 · MCQ
The electric field of light wave is given as $E = 1 0^{- 3} cos (\frac{2 π x}{5 \times 10 ^{- 7}} - 2 π \times 6 \times 10^{14} t) x \land \frac{N}{C}$ This light falls on…2019 · 9 Apr · Shift 1 · Q60 · MCQ
A particle 'P' is formed due to a completely inelastic collision of particles 'x' and 'y' having de-Broglie wavelengths ' $λ$ x' and ' $λ$ y' respectively. If x and y were moving in opposite directions, then the de-Broglie…2019 · 9 Apr · Shift 2 · Q62 · MCQ
Surface of certain metal is first illuminated with light of wavelength $λ$ 1 = 350 nm and then, by light of wavelength $λ$ 2 = 540 nm. It is found that the maximum speed of the photo electrons in the two cases differ by a…2019 · 9 Jan · Shift 1 · Q63 · MCQ
The magnetic field associated with a light wave is given, at the origin, by B = B0 [sin(3.14 $\times$ 107)ct + sin(6.28 $\times$ 107)ct]. If this light falls on a silver plate having a work function of 4.7 eV, what will be the maximum…2019 · 9 Jan · Shift 2 · Q53 · MCQ
In a photoelectric effect experiment the threshold wavelength of the light is 380 nm. If the wavelentgh of incident light is 260 nm, the maximum kinetic energy of emitted electrons will be: Given E (in eV) = 1237/ $λ$ (in nm)2019 · 10 Apr · Shift 1 · Q47 · MCQ
A 2 mW laser operates at wavelength of 500 nm. The number of photons that will be emitted per second is : [Given Planck's constant h = 6.6 × 10–34 Js, speed of light c = 3.0 × 108 m/s]2019 · 10 Apr · Shift 2 · Q68 · MCQ
In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5 × 10–12 m, the minimum electron energy required is close to -2019 · 10 Jan · Shift 1 · Q51 · MCQ
A metal plate of area 1 $\times$ 10–4 m2 is illuminated by a radiation of intensity 16 mW/m2. The work function of the metal is 5 eV. The energy of the incident photons is 10 eV and only 10% of it produces photo electrons. The number of…2019 · 10 Jan · Shift 2 · Q73 · MCQ
If the de Broglie wavelength of an electron is equal to the 10–3 times the wavelength of a photon of frequency 6 $\times$ 1014 Hz, then the speed of electron is equal to : (Speed of light = 3 $\times$ 108 m/s, Planck's constant = 6.63 $\times$ …2019 · 11 Jan · Shift 1 · Q62 · MCQ
In a photoelectric experiment, the wavelength of the light incident on a metal is changed from 300 nm to 400 nm. The decrease in the stopping potential is close to: ( $\frac{h c}{e}$ = 1240 nm eV)2019 · 11 Jan · Shift 2 · Q56 · MCQ
The stopping potential V0 (in volt) as a function of frequency ( $υ$ ) for a sodium emitter, is shown in the figure. The work function of sodium, from the data plotted in the figure, will be: (Given: Planck’s constant (h) = 6.63 ×… Includes diagram2019 · 12 Apr · Shift 1 · Q62 · MCQ
A particle A of mass 'm' and charge 'q' is accelerated by a potential difference of 50 V. Another particle B of mass ' 4 m' and charge 'q' is accelerated by a potential difference of 2500 V. The ratio of de-Broglie wavelengths $\frac{λ _{A}}{λ _{B}}$ …2019 · 12 Jan · Shift 1 · Q63 · MCQ
When a certain photosensitive surface is illuminated with monochromatic light of frequency v, the stopping potential for the current is –V0/2. When the surface is illuminated by monochromatic light of frequency v/2, the stopping potential…2019 · 12 Jan · Shift 2 · Q55 · MCQ
In a Frank-Hertz experiment, an electron of energy 5.6 eV passes through mercury vapour and emerges with an energy 0.7 eV. The minimum wavelength of photons emitted by mercury atoms is close to :2019 · 12 Jan · Shift 2 · Q57 · MCQ
Two electrons are moving with non-relativistic speed perpendicular to each other. If corresponding de Broglie wavelength are $λ_{1}$ and $λ_{2},$ their de Broglie wavelength in the frame of reference attached to their center…2018 · 15 Apr · Shift 1 · Q55 · MCQ
If the de Broglie wavelengths associated with a proton and an $α$ -particle are equal, then the ratio of velocities of the proton and the $α$ -particle will be :2018 · 15 Apr · Shift 2 · Q71 · MCQ
Both the nucleus and the atom of some element arein their respective first excited states. They get de-excted by emitting photons of wavelengths $λ$ N, $λ$ A respectively. The ratio $\frac{^{λ} N}{^{λ} A}$ is…2018 · 16 Apr · Shift 1 · Q49 · MCQ
The de-Broglie wavelength ( $λ$ B) associated with the electron orbiting in the second excited state of hydrogen atom is related to that in the ground state ( $λ$ G) by :2018 · 16 Apr · Shift 1 · Q50 · MCQ
The maximum velocity of the photoelectrons emitted from the surface is v when light of frequency n falls on a metal surface. If the incident frequency is increased to 3n, the maximum velocity of the ejected photoelectrons will be :2017 · 8 Apr · Shift 1 · Q60 · MCQ
A Laser light of wavelength 660 nm is used to weld Retina detachment. If a Laser pulse of width 60 ms and power 0.5 kW is used the approximate number of photons in the pulse are : [Take Planck's constant h $=$ 6.62 $\times$ 10 $-$ 34 Js]2017 · 9 Apr · Shift 1 · Q54 · MCQ
An electron beam is accelerated by a potential difference V to hit a metallic target to produce X–rays. It produces continuous as well as characteristic X-rays. If $λ$ min is the smallest possible wavelength of X-ray in the spectrum,…2017 · Shift 0 · Q55 · MCQ
A particle A of mass m and initial velocity v collides with a particle B of mass m/2 which is at rest. The collision is head on, and elastic. The ratio of the de-Broglie wavelengths $λ_{A}$ to $λ_{B}$ after the collision is:2017 · Shift 0 · Q69 · MCQ
When photons of wavelength $λ_{1}$ are incident on an isolated sphere, the corresponding stopping potential is found to be V. When photons of wavelength $λ_{2}$ are used, the corresponding stopping potential was thrice that…2016 · 9 Apr · Shift 1 · Q58 · MCQ
A photoelectric surface is illuminated successively by monochromatic light of wavelengths $λ$ and $\frac{λ}{2} .$ If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case,…2016 · 10 Apr · Shift 1 · Q52 · MCQ
Radiation of wavelength $λ,$ is incident on a photocell. The fastest emitted electron has speed $v .$ If the wavelength is changed to $\frac{3 λ}{4},$ the speed of the fastest emitted electron will be:2016 · Shift 0 · Q40 · MCQ
The anode voltage of a photocell is kept fixed. The wavelength $λ$ of the light falling on the cathode is gradually changed. The plate current $I$ of the photocell varies as follows :2013 · Shift 0 · Q50 · MCQ
This question has Statement - $1$ and Statement - $2$ . Of the four choices given after the statements, choose the one that best describes the two statements. Statement - $1$ : A metallic surface is irradiated by a monochromatic light of…2011 · Shift 0 · Q53 · MCQ
If a source of power $4 k W$ produces $1 0^{20}$ photons/second, the radiation belongs to a part of the spectrum called2010 · Shift 0 · Q52 · MCQ
Statement - $1$ : When ultraviolet light is incident on a photocell, its stopping potential is $V_{0}$ and the maximum kinetic energy of the photoelectrons is $K_{m a x}$ . When the ultraviolet light is replaced by $X$ -rays, both $V_{0}$ …2010 · Shift 0 · Q55 · MCQ
The surface of a metal is illuminated with the light of $400 nm .$ The kinetic energy of the ejected photoelectrons was found to be $1.68 e V .$ The work function of the metal is : $(h c = 1240 e V . nm)$ 2009 · Shift 0 · Q51 · MCQ
In an experiment, electrons are made to pass through a narrow slit of width $^{'} d^{'}$ comparable to their de Broglie wavelength. They are detected on a screen at a distance $^{'} D^{'}$ from the slit (see figure). Which of the following graphs can be… Includes diagram2008 · Shift 0 · Q61 · MCQ
Photon of frequency $v$ has a momentum associated with it. If $c$ is the velocity of light, the momentum is2007 · Shift 0 · Q67 · MCQ
The anode voltage of a photocell is kept fixed. The wavelength $λ$ of the light falling on the cathode is gradually changed. The plate current $I$ of the photocell varies as follows2006 · Shift 0 · Q86 · MCQ
The threshold frequency for a metallic surface corresponds to an energy of $6.2 e V$ and the stopping potential for a radiation incident on this surface is $5 V .$ The incident radiation lies in2006 · Shift 0 · Q97 · MCQ
The time taken by a photoelectron to come out after the photon strikes is approximately2006 · Shift 0 · Q99 · MCQ
A photocell is illuminated by a small bright source placed $1 m$ away. When the same source of light is placed $\frac{1}{2} m$ away, the number of electrons emitted by photo-cathode would2005 · Shift 0 · Q119 · MCQ
If the kinetic energy of a free electron doubles, it's deBroglie wavelength changes by the factor2005 · Shift 0 · Q140 · MCQ
The work function of a substance is $4.0 e V .$ The longest wavelength of light that can cause photo-electron emission from this substance is approximately.2004 · Shift 0 · Q120 · MCQ
According to Einstein's photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal $V s$ the frequency, of the incident radiation gives as straight the whose slope2004 · Shift 0 · Q122 · MCQ
Two identical photo-cathodes receive light of frequencies $f_{1}$ and $f_{2}$ . If the velocities of the photo electrons (of mass $m$ ) coming out are respectively $v_{1}$ and $v_{2},$ then2003 · Shift 0 · Q122 · MCQ
Sodium and copper have work functions $2.3 e V$ and $4.5 e V$ respectively. Then the ratio of the wavelengths is nearest to2002 · Shift 0 · Q137 · MCQ
Formation of covalent bonds in compounds exhibits2002 · Shift 0 · Q138 · MCQ