CBSE Class 12 (Science) Dual Nature of Radiation and Matter — practice questions
83 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 (Science) Dual Nature of Radiation and Matter in the app →In a photoelectric experiment, the minimum negative potential applied to the collector plate at which the photThe momentum carried by a photon of wavelength $\lambda$ isThe minimum energy needed to free an electron from a metal is its:Work function is usually measured in:Photoelectric emission was discovered in 1887 by:Below the threshold frequency, photoelectric emission:The maximum photoelectric current at high positive voltage is the:The negative voltage that just stops the current is called the:Photoelectric emission begins after a time lag that is:Who explained the photoelectric effect in 1905?In Einstein's picture, radiation travels as:The number of photoelectrons emitted per second depends on the:The kinetic energy of the photoelectrons is set by the:Increasing the intensity of light leaves the stopping potential:The work function of a surface depends on the:Who proposed that matter also has a wave nature?The waves associated with moving particles are called:The de Broglie relation contains a wave concept together with a:Ultraviolet light causing emission was studied in detail by:However intense the light, no emission occurs below the:Photoelectric current falls to zero at which voltage?The de Broglie wavelength of a fast electron is comparable with:Photoelectric emission was discovered in the year:Who discovered photoelectric emission?Hallwachs and Lenard investigated photoelectric emission during:Lenard observed photoemission when he used radiation that was:The minimum frequency below which no photoemission occurs is the:The minimum energy needed for an electron to escape a metal is the:The work function is usually measured in:One electron volt is the energy gained by an electron accelerated through:Which metal has the highest work function?Who performed the pioneering oil-drop experiment?In interaction with matter, radiation behaves as if made of:The energy of a photon is given by:The momentum of a photon is given by:A photon travels at a speed equal to that of:Increasing the intensity of light of a given wavelength increases the:Photon energy is independent of the radiation's:In a photon-particle collision, what may not be conserved?Who proposed the idea of matter waves in 1924?De Broglie was a physicist of which nationality?De Broglie was awarded the Nobel Prize in Physics in:The wave nature of electrons was confirmed by Davisson and:The de Broglie hypothesis of matter waves supports the stationary orbits of:Which experiment showed that electric charge is quantised?One electron volt is equal to how many joules?On what does the work function of a metal depend?Release of electrons from a metal by heating it is called what?Field emission pulls electrons out of a metal using a field of about what size?Who discovered photoelectric emission in 1887 while producing radio waves?Which kind of light made the detector sparks stronger in Hertz's experiment?What is the minimum frequency below which a metal emits no photoelectrons called?Which group of metals responds even to visible light in photoemission?Zinc, cadmium and magnesium cause photoemission only with which radiation?At fixed frequency and plate potential, how does photocurrent vary with intensity?How is the maximum kinetic energy of photoelectrons related to stopping potential V0?The energy of emitted photoelectrons depends on which property of the light?Above the threshold frequency, how long is the delay before photoemission starts?According to wave theory, electron energy should increase with what?Who proposed light quanta in 1905 to explain the photoelectric effect?How is the threshold frequency related to work function φ0 and Planck constant h?A 4.0 eV photon hits a metal of work function 2.5 eV. What is Kmax?Light of photon energy 4.2 eV falls on a metal with work function 2.2 eV. What is the stopping potential?When stopping potential is plotted against frequency, what does the slope equal?Who measured Planck constant from the slope of the V0 versus frequency line for sodium?Millikan set out to disprove Einstein's photoelectric equation. What was the result?What momentum does a photon of frequency ν carry?A laser emits light of frequency 6.0 × 10¹⁴ Hz. What is each photon's energy?A 2.0 mW source emits photons of 3.98 × 10⁻¹⁹ J each. How many per second?Caesium has work function 2.14 eV. Its threshold frequency is about what?Who proposed in 1924 that moving particles of matter show wave behaviour?What is the de Broglie wavelength of a particle of mass m and speed v?De Broglie argued that matter should be wave-like because nature is what?What does the de Broglie wavelength of a photon equal?A particle's speed is doubled. By what factor does its de Broglie wavelength change?A proton and an alpha particle have equal speeds. What is λ(proton) : λ(alpha)?Two particles have equal kinetic energy, one four times as massive. Ratio of heavy to light wavelength?A 0.12 kg ball moves at 20 m/s. Its de Broglie wavelength is about what?Why do everyday objects show no wave behaviour?An electron's de Broglie wavelength is comparable to the wavelength of which radiation?Davisson and Germer fired slow electrons at a crystal of which metal?Davisson and Germer's electron experiment demonstrated what?A Vienna team in 1999 showed matter-wave diffraction for which molecules?