Dual Nature of Radiation and Matter

CBSE Class 12 Physics · every board question from this chapter, 2022–2026 · 45 of them repeated across years

• A 500 nm photon is incident normally on a perfectly reflecting surface and is reflected. The value of momentum transferred to the…2026
• The momentum of a photon associated with a microwave of wavelength 4 · 00 cm is:2026
• A photosensitive surface is illuminated by radiations of wavelength λ 1, λ 2 ( λ 1) and λ 3 one by one and photoemission is…2026
• The maximum kinetic energy of the electrons emitted from a photo sensitive surface depends on2026
• Light of which of the following colours will have the maximum energy in a photon associated with it?2026
• While studying photoelectric emission from a given surface, the wavelength of the incident radiation is changed from 600 nm to…2026
• Radiation of wavelength 200 nm is incident on a photosensitive surface of work function 4 · 2 eV. The kinetic energy of fastest…2026asked 2×
• Radiation of wavelength 331 nm irradiates the following metals: Which of the following statements is correct?2026asked 3×
• A proton and an alpha particle have equal momentum. The ratio of their kinetic energies ( E p / E a ) and de Broglie wavelengths…2026
• The kinetic energy of a charged particle is increased to four times of its initial value. The de Broglie wavelength associated…2026asked 3×
• The equivalent mass of a photon of wavelength 100 nm is2026
• The velocity of the photoelectrons emitted from a surface depends upon the: Wavelength of incident radiation only Intensity of…2026
• In an experiment on photoelectric emission, the intensity of incident radiation is halved keeping its frequency constant. As a…2026
• Photons of frequency v are incident on the surfaces of two metals A and B of threshold frequencies v/2 and v/3. The ratio of…2026
• Assertion: On increasing the intensity of incident light of frequency v( v 0) on a photosensitive surface, the photocurrent…2026asked 3×
• Assertion: If accelerated electrons are passed through a narrow slit, a diffraction pattern is observed. Reason (R): Electrons…2026asked 3×
• Assertion: Photoelectric current depends upon the intensity of the incident radiation. Reason (R): Stopping potential is…2026asked 3×
• Assertion: Photoelectric effect is a spontaneous phenomenon. Reason (R): According to the wave picture of radiation, an electron…2026asked 3×
• In a photoelectric experiment, the emitter plate is irradiated with radiation of 200 nm. The photocurrent becomes zero when the…2026
• Calculate the de Broglie wavelength of a neutron having kinetic energy of 150 eV.2026
• Find ratio (λ a / λ p) of the de Broglie wavelength λ a and λ p associated respectively with an alpha particle and a proton, (i)…2026asked 3×
• Find the ratio ( λ aλ p) of de Broglie wavelength λ a associated with an alpha particle to de Broglie wavelength λ p associated…2026
• Light of frequency 5 · 0 × 10^14 Hz is incident on a metal surface. If the maximum speed of photoelectrons emitted is 6.63 × 10^5…2026
• In an electron microscope, accelerated electrons have wavelength of 0.011 nm. Calculate the voltage through which electrons were…2026
• A particle of mass M at rest splits up into two particles of masses m 1 and m 2 having non-zero velocities. Calculate the ratio…2026
• What are X-rays? How are they produced? Give two uses of X-rays.2026
• Explain how the dual aspect of matter is evident in the de Broglie relation. Radiation of wavelength λ is incident on a…2026asked 3×
• Photoemission of electrons occurs from a metal ( φ 0=1 · 96 eV ) when light of frequency 6.4 × 10^14 Hz is incident on it.…2026asked 3×
• A particle of charge q and mass m is accelerated through a potential difference V. Deduce an expression for the de Broglie…2026
• What are de Broglie waves? Show that the wavelength of the electromagnetic radiation is equal to the de Broglie wavelength of its…2026
• A researcher performs an experiment on photo-electric effect using two metals A and B with unknown work functions. She…2026asked 3×
• The frequency of a photon of energy 1 · 326 eV is:2025asked 3×
• A source produces monochromatic light of frequency 5.0 × 10^14 Hz and the power emitted is 3.31 mW. The number of photons emitted…2025
• The stopping potential V 0 measured in a photoelectric experiment for a metal surface is plotted against frequency v of the…2025
• Choose the correct statement:2025asked 3×
• In a photoelectric experiment with a material of work function 2.1 eV, the stopping potential is found to be 2.5 V. The maximum…2025
• Atomic spectral emission lines of hydrogen atom are incident on a zinc surface. The lines which can emit photoelectrons from the…2025asked 3×
• A beam of red light and a beam of blue light have equal intensities. Which of the following statements is true?2025asked 3×
• The de Broglie wavelength associated with an electron moving with energy 5 eV is:2025
• Let λ e, λ p and λ d be the wavelengths associated with an electron, a proton and a deuteron, all moving with the same speed.…2025asked 3×
• The work function of a material is 2 · 21 eV. Which of the following cannot produce photoelectrons from it?2025
• The wavelength of a photon is equal to the wavelength associated with an electron. Both will have the same value of:2025
• The momentum (in kg m / s ) of a photon of frequency 6.0 × 10^14 Hz is:2025asked 3×
• The kinetic energy of an alpha particle is four times the kinetic energy of a proton. The ratio ( λ αλ p) of de Broglie…2025asked 3×
• Assertion: X-rays are produced when slow moving electrons are stopped by a metal target of high atomic number. Reason (R): X-rays…2025asked 3×
• Assertion: For monochromatic incident radiation, the emitted photoelectrons from a given metal have speed ranging from zero to a…2025asked 3×
• Assertion: The minimum negative potential applied to the anode in a photoelectric experiment at which photoelectric current…2025asked 3×
• The threshold frequency for a given metal is 3.6 × 10^14 Hz. If monochromatic radiations of frequency 6.8 × 10^14 Hz are incident…2025asked 3×
• A laser beam of wavelength 500 nm and power 5 mW strikes normally on a perfectly reflecting surface of area 1 mm^2 of a body. It…2025
• A laser beam of frequency 3.0 × 10^14 Hz produces average power of 9 mW. Find (i) the energy of photon of the beam, and (ii) the…2025
• Radiations of two frequencies are incident on a metal surface of work function 2.0 eV one by one. The energies of their photons…2025
• The threshold wavelength of a metal is 450 nm. Calculate (i) the work function of the metal in eV and (ii) the maximum energy of…2025
• A light of wavelength 400 nm is incident on metal surface whose work function is 3.0 × 10^-19 J. Calculate the speed of the…2025
• Briefly explain Einstein's photoelectric equation. Four metals with their work functions are listed below: K=2 · 3 eV, Na=2 · 75…2025
• Answer the following, giving reasons: The maximum kinetic energy of the photoelectrons is independent of the intensity of…2025
• Draw a plot of frequency v of incident radiations as a function of stopping potential V 0 for a given photo emissive material.…2025
• Mention any three features of results of experiment on photoelectric effect which cannot be explained using the wave theory of…2025
• Answer the following giving reason: All the photo electrons do not eject with the same kinetic energy when monochromatic light is…2025
• Define 'work function' of a metal. How can its value be determined from a graph between stopping potential and frequency of the…2025
• Explain the following observations using Einstein's photoelectric equation: Photoelectric emission does not occur from a surface…2025asked 3×
• Einstein explained photoelectric effect on the basis of Planck's quantum theory, where light travels in the form of small bundles…2025asked 2×
• Einstein explained photoelectric effect on the basis of Planck's quantum theory, where light travels in the form of small bundles…2025
• When a photon of suitable frequency is incident on a metal surface, photoelectron is emitted from it. If the frequency is below a…2025asked 3×
• The quantum nature of light explains the observations on photoelectric effect as -2024asked 3×
• A photosensitive surface has a work function of 2 · 00 eV. The maximum kinetic energy of electrons ejected from this surface by…2024
• The variation of the stopping potential ( V 0 ) with the frequency ( v ) of the incident radiation for four metals A, B, C and D…2024asked 2×
• The work function for a photosensitive surface is 3 · 315 eV. The cut-off wavelength for photoemission of electrons from this…2024
• The momentum (in SI units) associated with a photon of energy 1 · 5 eV is:2024
• The figure shows the variation of stopping potential V 0 with frequency v of incident radiation, for three materials M 1, M 2 and…2024
• The variation of the stopping potential ( V 0 ) with the frequency ( v ) of the incident radiation for four metals A, B, C and D…2024
• Which one of the following is the correct graph between the maximum kinetic energy ( K m ) of the emitted photoelectrons and the…2024
• The wavelength of matter wave associated with an electron of kinetic energy K is λ. If the kinetic energy of the electron is…2024
• Two beams, A and B whose photon energies are 3 · 3 eV and 11 · 3 eV respectively, illuminate a metallic surface (work function 2…2024asked 3×
• The waves associated with a moving electron and a moving proton have the same wavelength λ. It implies that they have the same:2024asked 3×
• Assertion: Photoelectric current increases with an increase in intensity of incident radiation, for a given frequency of incident…2024asked 3×
• Assertion: In photoelectric effect, the kinetic energy of the emitted photoelectrons increases with increase in the intensity of…2024asked 3×
• Assertion: Electrons are ejected from the surface of zinc when it is irradiated by yellow light. Reason (R): Energy associated…2024asked 3×
• Assertion: Photoelectric effect demonstrates the particle nature of light. Reason (R): Photoelectric current is proportional to…2024asked 3×
• What are matter waves? A proton, an electron and an α -particle have the same kinetic energy. Write the de Broglie wavelengths…2024
• The ratio of de Broglie wavelengths of a proton and a deuteron accelerated by potential V p and V d respectively, ((λ p)/(λ d))…2024
• A proton and α -particle are accelerated through different potentials V 1 and V 2 respectively so that they have the same de…2024
• Consider a neutron (mass m ) of kinetic energy E and a photon of the same energy. Let λ n and λ p be the de Broglie wavelength of…2024asked 3×
• Light of wavelength 500 nm is incident on caesium metal (work function 2 · 14 eV ) and photoemission of electrons occurs.…2024
• Light of wavelength 600 nm is incident on potassium (work function 2.3 eV). Will photoemission of electrons occur? What is the…2024
• The minimum intensity of white light that our eyes can perceive is about 0.1 nWm^-2. Calculate the number of photons of this…2024
• Write Einstein's photoelectric equation. How did Millikan prove the validity of this equation? Explain the existence of threshold…2024
• A photosensitive surface of work function 2.1 eV is irradiated by radiation of wavelength 150 nm. Calculate (i) the threshold…2024
• The threshold frequency for a metal is 3.0 × 10^14 Hz. A beam of frequency 9.0 × 10^14 Hz is incident on the metal. Calculate (i)…2024
• Briefly explain de Broglie hypothesis for wave nature of matter. Find the ratio of de Broglie wavelength associated with a proton…2024
• de Broglie wavelength λ as a function of 1√ K, for two particles of masses m 1 and m 2 are shown in the figure. Here, K is the…2024
• The energy of a photon of wavelength 663 nm is2023
• The momentum of a photon of wavelength λ is:2023
• A light of frequency v is incident on a metal surface whose work function is W 0. The kinetic energy of emitted electron is K. If…2023
• In an experiment, photons of energy 7 · 5 eV are incident on a metal surface. Electrons emitted from the metal surface are…2023
• Photons of energy 3 · 2 eV are incident on a photosensitive surface. If the stopping potential for the emitted electrons is 1.5…2023asked 2×
• E, c and v represent the energy, velocity and frequency of a photon. Which of the following represents its wavelength?2023
• In an experiment on photoelectric effect, the intensity of incident radiation is increased, keeping the frequency v the same. The…2023
• The energy of a photon of wavelength λ is2023asked 2×
• Which one of the following metals does not exhibit emission of electrons from its surface when irradiated by visible light?2023
• A graph is plotted between the stopping potential (on y -axis) and the frequency of incident radiation (on x -axis) for a metal.…2023
• Which of the following graphs correctly represents the variation of a particle momentum with its associated de-Broglie wavelength?2023
• Which of the following graphs correctly represents the variation of a particle momentum with its associated de-Broglie wavelength?2023
• Figure shows a plot of stopping potential (V 0) versus 1/(λ), where λ is the wavelength of the radiation causing photoelectric…2023
• Light of frequency 6.4 × 10^14 Hz is incident on a metal of work function 2 · 14 eV. The maximum kinetic energy of the emitted…2023asked 3×
• A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum kinetic…2023
• A proton and an alpha particle have the same kinetic energy. The ratio of de Broglie wavelengths associated with the proton to…2023asked 3×
• Assertion: Photoelectric effect demonstrates the particle nature of light. Reason ( R ): Photoelectric current is proportional to…2023asked 3×
• Plot a graph showing the variation of photo electric current, as a function of anode potential for two light beams having the…2023
• How will the De Broglie wavelength associated with an electron be affected when the (i) velocity of the electron decreases? and…2023asked 3×
• The figure shows v m^2 versus 1/(λ) graph for photoelectrons emitted from a surface where v m is the maximum speed of electrons…2023asked 3×
• A particle of mass m and charge q is accelerated through a potential difference V. Plot a graph of de Broglie wavelength λ…2023
• The threshold wavelength for a metal is 3315. What should be the wavelength of light incident on the metal surface so that the…2023
• Calculate the wavelength of de Broglie waves associated with a proton having (500/(1 · 673)) eV energy. How will the wavelength…2023
• How does Einstein's photoelectric equation explain the emission of electrons from a metal surface? Explain briefly. Plot the…2023
• A particle is associated with a de Broglie wave of wavelength 1.2 nm. The kinetic energy of the particle is made four times.…2023
• The figure shows de Broglie wavelength ( λ ) for two particles A and B having same charges but different masses as a function of…2023
• Figure shows the variation of photoelectric current measured in a photo cell circuit as a function of the potential difference…2023asked 3×
• Draw the circuit diagram of an illuminated photodiode and its I-V charcteristics. 1 How can a photodiode be used to measure the…2022
• Name the spectral series for a hydrogen atom which lies in the visible region. Find the ratio of the maximum to the minimum…2022asked 3×
• What results do you expect if α -particle scattering experiment is repeated using a thin sheet of hydrogen in place of a gold…2022asked 3×
• How is an emf generated by a solar cell due to the three basic processes involved? Explain.2022
• Calculate the frequency of a photon of energy 6.5 × 10^-19 J. Can this photon cause emission of an electron from the surface of…2022
• Ultra-violet light of wavelength 200 nm from a source is incident on a metal surface. If the stopping potential is -2.5 V,…2022
• An alpha particle is accelerated through a potential difference of 100 V. Calculate: (i) The speed acquired by the alpha…2022
• The work function of a metal is 2.31 eV. Photoelectric emission occurs when light of frequency 6.4 × 10^14 Hz is incident on the…2022
• The de-Broglie wavelength associated with an electron is 0.30 nm. Calculate: the speed, and the kinetic energy (in eV), of the…2022
• Give an example each of a metal from which photoelectric emission takes place when irradiated by (i) UV light (ii) visible light.…2022
• The wavelength of the waves associated with a particle having kinetic energy E is λ. How and by what factor should its kinetic…2022
• A proton is accelerated through a potential difference V. After acceleration, the de Broglie wavelength associated with it is λ.…2022
• Calculate the energy and momentum of a photon in a monochromatic beam of wavelength 331.5 nm. How fast should a hydrogen atom…2022
• Use Einstein's photoelectric equation to depict the variation of the maximum kinetic energy ( E k ) of electrons emitted, with…2022
• An electron is accelerated from rest through a potential difference of 100 V. Find: (i) the wavelength associated with (ii) the…2022
• Photoelectrons are emitted from a metal surface when illuminated with UV light of wavelength 330 nm. The minimum amount of energy…2022
• Find the ratio of the de Broglie wavelengths associated with an alpha particle and a proton, if both have the same speeds, have…2022asked 3×

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