Dual Nature of Radiation & Matter — practice questions

157 curated practice questions from Dual Nature of Radiation & Matter (Physics Class 12, CBSE) — 118 easy, 32 medium, 7 hard. Every question includes the final answer free; step-by-step worked solutions with a free account.

• Assertion (A): Photoelectric current increases with an increase in intensity of incident radiation, for a given…
• Assertion (A): A photon has no rest mass, yet it carries definite momentum. Reason (R): Momentum of a photon is due to…
• A light of frequency v is incident on a metal surface whose work function is W 0 . The kinetic energy of emitted…
• In a photoelectric experiment with a material of work function 2.1 eV, the stopping potential is found to be 2.5 V. The…
• An electron of mass m with an initial velocity v =v_ 0 i is in an electric field E =E_ 0 j . If _ 0 = h m v_ 0 , its de…
• Which one of the following is the correct graph between the maximum kinetic energy (K m ) of the emitted photoelectrons…
• In an experiment, photons of energy 7.5 eV are incident on a metal surface. Electrons emitted from the metal surface…
• For the same objective, what is the ratio of the least separation between two points to be distinguished by a…
• A metallic surface is irradiated by a monochromatic light of frequency _1 and stopping potential is found to be V_1 …
• The frequency of a photon of energy 1 326 eV is:
• Assertion (A): When a certain wavelength of light falls on a metal surface it ejects electrons. Reason (R): Light has…
• The correct graph representing the relation between energy (E) of photoelectrons and frequency of incident light is
• If a photon has velocity c and frequency , then which of the following represents its wavelength?
• If a proton and electron have the same de Broglie wavelength, then
• A and B are two metals with threshold frequencies 1.8 × 10 14 Hz and 2.2 × 10 14 Hz. Two identical photons of energy…
• Two particles A 1 and A 2 of masses m 1 , m 2 ( m 1 > m 2 ) have the same de Broglie wavelength. Then
• A source produces monochromatic light of frequency 5.0 10^ 14 ~Hz and the power emitted is 3.31 mW. The number of…
• Assertion (A): For monochromatic incident radiation, the emitted photoelectrons from a given metal have speed ranging…
• Light of frequency 1.5 v 0 is incident on a photosensitive material of threshold frequency v 0 . If the frequency of…
• Three particles having charges in the ratio of 2 : 3 : 5 produces the same point on the photographic film in the…
• Assertion (A): In photoelectric effect, the kinetic energy of the emitted photoelectrons increases with increase in the…
• Which of the following statements is correct regarding the photoelectric experiment?
• Assuming an electron is confined to a 1 nm wide region. Find the uncertainty in momentum using Heisenberg uncertainty…
• G.P. Thomson experimentally confirmed the existence of matter waves by the phenomena
• In photoelectric effect, the photoelectric current is independent of
• A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum…
• The matter-wave picture of electromagnetic wave/radiation elegantly incorporated the
• A photosensitive surface has a work function of 2.00 eV. The maximum kinetic energy of electrons ejected from this…
• The waves associated with a moving electron and a moving proton have the same wavelength . It implies that they have…
• The figure shows the variation of maximum kinetic energy ( K _ ) of emitted electrons as a function of the frequency v…
• Figure shows a plot of stopping potential (V 0 ) versus 1 , where is the wavelength of the radiation causing…
• In photoelectric effect, electrons are ejected from metals, if the incident light has a certain minimum:
• What is the frequency of photon in question number 46?
• A blue lamp mainly emits light of wavelength 4500 Å. The lamp is rated at 150 W and 8% of the energy is emitted as…
• If the momentum of an electron is changed by p , then the de Broglie wavelength associated with it changes by 0.5%. The…
• The energy flux of sunlight reaching the surface of the earth is 1.388 × 10 3 W m –2 . The photons in the sunlight have…
• In a photoelectric experiment, if both the intensity and frequency of the incident light are doubled, then the…
• The figure shows the variation of stopping potential V _0 with frequency v of incident radiation, for three materials M…
• An X-ray tube produces a continuous spectrum of radiation with its short wavelength end at 0.45 Å. The maximum energy…
• Photons of energy 3.2 eV are incident on a photosensitive surface. If the stopping potential for the emitted electrons…
• Assertion (A): As work function of a material increases by some mechanism, it requires greater energy to excite the…
• We wish to see inside an atom. Assuming the atom to have a diameter of 100 pm [1 picometre (pm) = 10 -12 m], this means…
• A photon of energy 7 eV is incident on a metal surface having the work function of 3.75 eV. The stopping potential is:
• A proton and an alpha particle have the same kinetic energy. The ratio of de Broglie wavelengths associated with the…
• A radiation of energy E falls normally on a perfectly reflecting surface. The momentum transferred to the surface (c =…
• According to Einstein’s photoelectric equation, the graph of kinetic energy of the photoelectron emitted from the metal…
• The minimum energy required for the electron emission from the metal surface can be supplied to the free electrons by…
• An electron of mass m with an initial velocity is in an electric field E =-E_ 0 i ( E 0 = constant > 0). Its de Broglie…
• Electrons with de Broglie wavelength l fall on the target in an X ray tube. The cut off wavelength ( l 0 )of the…
• Atomic spectral emission lines of hydrogen atom are incident on a zinc surface. The lines which can emit photoelectrons…
• Photoelectric emission occurs only when the incident light has more than a certain minimum
• The energy that should be added to an electron to reduce its de Broglie wavelength from one nm to 0.5 nm is
• The time taken by a photoelectron to come out after the photon strikes is approximately
• Which phenomenon best supports the theory that matter has a wave nature?
• Photons of energies 1 eV and 2 eV are successively incident on a metallic surface of work function 0.5 eV. The ratio of…
• In a photon-particle collision (such as photon-electron collision), which of the following is may not conserved ?
• Wave theory cannot explain the phenomena of A. Polarization B. Diffraction C. Compton effect D. Photoelectric effect…
• A photon of energy E ejects a photoelectron from a metal surface whose work function is φ 0 . If this electron enters…
• The stopping potential V _ 0 measured in a photoelectric experiment for a metal surface is plotted against frequency v…
• Monochromatic light of frequency 6 × 10 14 Hz is produced by a laser. The power emitted is 2 × 10 –3 W. The number of…
• Which of the following figure represents the variation of particle momentum ( p ) and associated de Broglie wavelength…
• Assertion (A): The minimum negative potential applied to the anode in a photoelectric experiment at which photoelectric…
• Consider the four gases hydrogen, oxygen, nitrogen and helium at the same temperature. Arrange them in the increasing…
• Consider a beam of electrons (each electron with energy E 0 ) incident on a metal surface kept in an evacuated chamber…
• The maximum frequency and minimum wavelength of X-rays produced by 30 kV electrons respectively is
• Assertion (A): Electrons are ejected from the surface of zinc when it is irradiated by yellow light. Reason (R): Energy…
• A neutron beam of energy K scatters from atoms on a surface with a spacing d = 0.1 nm. The first maximum of intensity…
• Assertion (A): In his study of photoelectric emission, Hallwachs connected a negatively charged zinc plate to an…
• The momentum (in kg m / s ) of a photon of frequency 6.0 10^ 14 ~Hz is:
• A metal surface ejects electrons when hit by green but none when hit by yellow light. The electrons will be ejected…
• The work function for Al, K and Pt is 4.28 eV, 2.30 eV and 5.65 eV respectively. Their respective threshold frequencies…
• In the question number 26, find the wavelength of the incident light if the stopping potential is 0.6 V.
• Assertion (A): An electron microscope is based on de Broglie hypothesis. Reason (R): A beam of electrons behaves as a…
• A graph is plotted between the stopping potential (on y-axis) and the frequency of incident radiation (on x-axis) for a…
• The de Broglie wavelength of a particle of kinetic energy K is λ. What will be the wavelength of the particle, if its…
• Which of these particles having the same kinetic energy) has the largest de Broglie wavelength?
• When the photons of energy h υ fall on a photosensitive metallic surface of work function h υ 0 , electrons are emitted…
• The figure shows stopping potential V 0 and frequency u for two different metallic surfaces A and B . The work function…
• Assertion (A): Photoelectric effect demonstrates the particle nature of light. Reason (R): Photoelectric current is…
• Light of frequency 7.21 × 10 14 Hz is incident on a metal surface. Electrons with a maximum speed of 6 × 10 5 m s – 1…
• Light with an energy flux of 25 10 4 Wm -2 falls on a perfectly reflecting surface at normal incidence. If the surface…
• A light of wavelength 600 nm is incident on a metal surface. When light of wavelength 400 nm is incident, the maximum…
• A proton and an a -particle are accelerated through the same potential difference. The ratio of de Broglie wavelength l…
• The photoelectrons emitted from a given cathode on the incidence of a given monochromatic beam of light have a/an
• Which of the following figures represents the variation of a particle's momentum with the de Broglie wavelength…
• In photoelectric effect, stopping potential depends on
• Assertion (A): Photoelectric effect demonstrates the particle nature of light. Reason (R): Photoelectric current is…
• Assertion (A): The de Broglie wavelength of a molecule varies inversely as the square root of temperature. Reason (R)…
• Photons of energy 4.3 eV are incident on a photosensitive surface of work function 2 3 eV. The stopping potential for…
• The momentum (in SI units) associated with a photon of energy 1.5 eV is:
• The de Broglie wavelength λ of an electron accelerated through a potential V in volts is
• The photoelectric threshold frequency of a metal is υ. When light of frequency 4υ is incident on the metal, the maximum…
• The particle nature and wave nature of electromagnetic waves and electrons can be shown by:
• There are two sources of light, each emitting with a power of 100 W. One emits X-rays of wavelength 1 nm and the other…
• When the velocity of an electron increases, its de Broglie wavelength
• The threshold frequency of a certain metal is 3.3 × 10 14 Hz. If light of frequency 8.2 × 10 14 Hz is incident on the…
• Which of the following graphs correctly represents the variation of a particle momentum with its associated de-Broglie…
• In an experiment on photoelectric effect, the intensity of incident radiation is increased, keeping the frequency v the…
• The de Broglie wavelength of an electron with kinetic energy 120 eV is (Given h = 6.63 × 10 –34 J s, m e = 9 × 10 –31…
• A student performs an experiment on photoelectric effect using two materials A and B . A plot of stopping potential ( V…
• Let _ e , _ p and _ d be the wavelengths associated with an electron, a proton and a deuteron, all moving with the same…
• If alpha particle, proton and electron move with the same momentum, then their respective de Broglie wavelengths λ α …
• Assertion (A): In photoelectron emission, the velocity of electron ejected from near the surface is larger than that…
• A particle of mass 4 m at rest decays into two particles of masses m and 3 m having non-zero velocities. The ratio of…
• For a certain metal, incident frequency υ is five times of threshold frequency υ 0 and the maximum velocity of coming…
• A particle A with a mass m A is moving with a velocity v and hits a particle B of mass m B at rest. If motion is one…
• The momentum of a photon of wavelength is:
• Two beams, A and B whose photon energies are 3.3 eV and 11.3 eV respectively, illuminate a metallic surface (work…
• Photons of frequency v are incident on the surfaces of two metals A and B of threshold frequencies 3 4 v and 2 3 v…
• Who won the Nobel prize in physics in the year 1929 for the discovery of the wave nature of electrons?
• The de Broglie wavelength of a photon is twice the de Broglie wavelength of an electron. The speed of the electron is…
• Which one among the following shows particle nature of light?
• The phenomenon of photoelectric emission was discovered in 1887 by
• The photoelectric cut off voltage in a certain experiment is 1.5 V. The maximum kinetic energy of photoelectrons…
• The variation of the stopping potential ( V _ 0 ) with the frequency ( v ) of the incident radiation for four metals A…
• The work function of a material is 2.21 eV. Which of the following cannot produce photoelectrons from it?
• An electromagnetic wave of wavelength λ is incident on a photosensitive surface of negligible work function. If the…
• In the question number 24, the energy of photon in eV at the red end of the visible spectrum is
• The wavelength of light in the visible region is about 390 nm for violet colour and about 760 nm for red colour. The…
• If the kinetic energy of a particle is increased by 16 times, the percentage change in the de Broglie wavelength of the…
• A 100 W sodium lamp radiates energy uniformly in all directions. The lamp is located at the centre of a large sphere…
• If K 1 and K 2 are maximum kinetic energies of photoelectrons emitted when lights of wavelength λ 1 and λ 2…
• E, c and v represent the energy, velocity and frequency of a photon. Which of the following represents its wavelength?
• Light of wavelengths λ falls on a metal having work function h c _ 0 . Photoelectric effect will take place only
• The work function of caesium is 2.14 eV. The threshold frequency of caesium is
• A proton, a neutron, an electron and an α-particle have same kinetic energy. Then their de Broglie wavelengths compare…
• The wavelength of matter wave associated with an electron of kinetic energy K is . If the kinetic energy of the…
• The graph showing the correct variation of linear momentum (p) of a charge particle with its de-Broglie wavelength ( )…
• A particle is moving three times as fast as an electron. The ratio of the de Broglie wavelength of the particle to that…
• The de Broglie wavelength of an electron in a metal at 27°C is (Given m e = 9.1 × 10 –31 kg, k B = 1.38 × 10 –23 J K –1…
• Which one of the following metals does not exhibit emission of electrons from its surface when irradiated by visible…
• The photoelectric threshold wavelength for silver is λ 0 . The energy of the electron ejected from the surface of…
• The wavelength of a photon is equal to the wavelength associated with an electron. Both will have the same value of:
• In an accelerator experiment on high energy collisions of electrons with positrons, a certain event is interpreted as…
• An α-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb m –2 . The de…
• An electron is moving with an initial velocity and is in a magnetic field B =B_ 0 j . Then its de Broglie wavelength
• If h is Planck’s constant, the momentum of a photon of wavelength 0.01 Å is
• A photocell connected in an electrical circuit is placed at a distance d from a source of light. As a result, current I…
• Assume that a molecule is moving with the root mean square speed at temperature 300 K. The de Broglie wavelength of…
• A particle moves in a closed orbit around the origin, due to a force which is directed towards the origin. The de…
• Which of the following statements about photon is incorrect?
• In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by
• The maximum value of photoelectric current is called
• A beam of red light and a beam of blue light have equal intensities. Which of the following statements is true?
• Photons absorbed in matter are converted to heat. A source emitting n photons per second of frequency u is used to…
• If the kinetic energy of the particle is increased by 16 times, the percentage change in the de Broglie wavelength of…
• The quantum nature of light explains the observations on photoelectric effect as -
• Which one of the given graphs correctly represents the variation of photoelectric current with the intensity of…
• Assertion (A): The de Broglie equation has significance for any microscopic or sub-microscopic particle. Reason (R)…
• If photons of frequency u are incident on the surfaces of metals. A & B of threshold frequencies v 2 and v 3…
• One MeV positron encounters 1 MeV electron travelling in opposite direction. What is the wavelength of photons…
• In Davisson and Germer experiment, the tungsten filament is coated with
• The de Broglie wavelength associated with a ball of mass 150 g travelling at 30 m s –1 is
• 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…
• Assertion (A): In process of photoelectric emission using a monochromatic light, all emitted electrons do not have the…
• Relativistic corrections become necessary when the expression for the kinetic energy 1 2 m v^ 2 , becomes comparable…
• A particle is dropped from a height H . The de Broglie wavelength of the particle as a function of height is…

← All Physics Class 12 chapters · All subjects