Dual Nature of Matter & Radiation PYQs Set 11 (PDF)

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Mere Teacher · Previous Year Questions JEE Main Physics · Dual Nature of Matter & Radiation · Set 11 (Q301-321)
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301. $Statement (I): By increasing the potential difference between cathode and anode continuously in a photoelectric experiment, the photo current always increases continuously. Statement (II): If two photons A and B of energies 2.5 eV and 3.5 eV respectively fall on a metal surface of work function 2.0 eV, then the ratio of maximum kinetic energies emitted between A and B is 3 . Statement (III): The maximum energy needed by an electron to come out from metal surface is called the work function of the metal. Which of the following is correct?$ (1) $Statements I, II and III are true$ (2) $Statements I, II are true, but statement III is false$ (3) $Statements II, III are true, but statement I is false$ (4) $Statements I, II and III are false$ 302. $Given below are two statements: Statement-I: In hydrogen atom, the frequency of radiation emitted when an electron jumps from lower energy orbit (E1) to higher energy orbit (E2), is given as hf = E1 - E2. Statement-II: The jumping of electron from higher energy orbit (E2) to lower energy orbit (E1) is associated with frequency of radiation given as f = \frac{E _{2} - E _{1}}{h} This condition is Bohr's frequency condition. In the light of the above statements, choose the correct answer from the options given below:$ (1) $Both statement I and statement II are true.$ (2) $Both statement I and statement II are false$ (3) $Statement I is correct but statement II is false$ (4) $Statement I is incorrect but statement II is true.$ 303. $An electron of mass m with a velocity v = v_{0} (v_{0} > 0) enters an electric field E = - E_{0} (E_{0} = constant > 0) at t = 0 . If λ_{0} is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is [NEET 2018]$ (1) $λ_{0} t$ (2) $λ_{0} (1 + \frac{e E _{0}}{m v _{0}} t)$ (3) $\frac{λ _{0}}{( 1 + \frac{c E _{0}}{m v _{0}} t )}$ (4) $λ_{0}$ 304. $The light of two different frequencies whose photons have energies 3.8 eV and 1.4 eV respectively, illuminate a metallic surface whose work function is 0.6 eV successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be:$ (1) $1 : 1$ (2) $2 : 1$ (3) $4 : 1$ (4) $1 : 4$ 305. $The electromagnetic theory of light failed to explain$ (1) $photoelectric effect$ (2) $polarization$ (3) $diffraction$ (4) $interference.$ 306. $A photo‐cell is illuminated by a source of light, which is placed at a distance d from the cell. If the distance become d /2, then number of electrons emitted per second will be$ (1) $remain same$ (2) $four times$ (3) $two times$ (4) $one‐fourth$ 307. $By photoelectric effect, Einstein proved$ (1) $E = h ν$ (2) $K . E . = \frac{1}{2} m v^{2}$ (3) $E = m c^{2}$ (4) $E = \frac{- Rh c ^{2}}{n ^{2}}$ 308. $In a discharge tube at 0.02 mm, there is formation of$ (1) $Crooke’s dark space$ (2) $Faraday’s dark space$ (3) $both space partly$ (4) $none of these$ 309. $In a photoelectric experiment, a monochromatic light is incident on the emitter plate E, as shown in the figure. When switch S_{1} is closed and switch S_{2} is open, the photoelectrons strike the collector plate C with a maximum kinetic energy of 1 eV . If switch S_{1} is open and switch S_{2} is closed and the frequency of the incident light is doubled the photoelectrons strike the collector plate with a maximum kinetic energy of 20 eV . The threshold wavelength of the emitter plate is$ (1) $5233.3Å$ (2) $4133.3Å$ (3) $4166.7Å$ (4) $5336.7Å$ 310. $In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of$ (1) $collisions between the charged particles emitted from the cathode and the atoms of the gas$ (2) $collision between different electrons of the atoms of the gas$ (3) $excitation of electrons in the atoms$ (4) $collision between the atoms of the gas.$ 311. $Which of the following phenomena does not explain by wave nature of light.(A) reflection(B) diffraction(C) photoelectric effect(D) interference(E) polarization Choose the most appropriate answer from the options given below:$ (1) $E only$ (2) $B, D only$ (3) $C only$ (4) $A, C only$ 312. $The de Broglie wave corresponding to a particle of mass m and velocity v has a wavelength associated with it$ (1) $\frac{h}{mv}$ (2) $hmv$ (3) $\frac{mh}{v}$ (4) $\frac{m}{hv}$ 313. $Which of the following statements is NOT true?$ (1) $Electromagnetic radiation is made up of particles called photons$ (2) $Each photon moves with the speed of light$ (3) $Photon energy is dependent on the intensity of radiation$ (4) $Photons are not deflected by electric and magnetic field$ 314. $When a proton is accelerated through 1 V, then its kinetic energy will be$ (1) $1 eV$ (2) $13.6 eV$ (3) $1840 eV$ (4) $0.54 eV$ 315. $The wave nature of electrons was experimentally verified by [NEET 2020]$ (1) $de-Broglie$ (2) $Hertz$ (3) $Einstein$ (4) $Davisson and Germer$ 316. $The energy of a photon of wavelength λ is$ (1) $hcλ$ (2) $\frac{hc}{λ}$ (3) $\frac{λ}{hc}$ (4) $\frac{λh}{c}$ 317. $Given below are two statements: Statement I: Figure shows the variation of stopping potential with frequency (v) for the two photosensitive materials M_{1} and M_{2} . The slope gives value of \frac{h}{e}, where h is Planck's constant, e is the charge of electron. Statement II: M_{2} will emit photoelectrons of greater kinetic energy for the incident radiation having same frequency. In the light of the above statements, choose the most appropriate answer from the options given below.$ (1) $Both Statement I and Statement II are correct$ (2) $Statement I is incorrect but Statement II is correct$ (3) $Both Statement I and Statement II are incorrect$ (4) $Statement I is correct and Statement II is incorrect$ 318. $Which of the following statement is not true about stopping potential (V_{0}) ?$ (1) $It is 1 /e times the maximum kinetic energy of electrons emitted.$ (2) $It increases with increase in intensity of the incident light.$ (3) $It depends on the nature of emitter material.$ (4) $It depends upon frequency of the incident light.$ 319. $Momentum of photon wavelength λ is$ (1) $\frac{h ν}{c}$ (2) $zero$ (3) $\frac{hλ}{c ^{2}}$ (4) $\frac{hλ}{c}$ 320. $In Thomson mass spectrograph E ⊥ B then the velocity of electron beam will be$ (1) $\frac{∣ E ∣}{∣ B ∣}$ (2) $E \times B$ (3) $\frac{∣ B ∣}{∣ E ∣}$ (4) $\frac{E}{B}$ 321. $The maximum kinetic energy of the photoelectrons depends only on$ (1) $incident angle$ (2) $potential$ (3) $pressure$ (4) $frequency$