JEE Questions for Physics Dual Nature Of Radiation And Matter Quiz 7 - MCQExams.com

Photo sensitive surface is incident by light having frequency 3 times its threshold frequency. In this condition, if frequency of light is made half and intensity of light is made double, magnitude of photo electric current becomes........................
  • Fourth
  • double
  • half
  • zero
If ratio of threshold frequencies of two metals is 1 : 3, ratio of their work functions is.............
  • 1 : 3
  • 3 : 1
  • 4 : 16
  • 16 : 4
It work function of Na and Fe are 2.5 eV and 5 eV respectively ratio of their threshold frequencies.........................
  • 2 : 1
  • 1 : 2
  • 125 : 1
  • 1 : 1
If electron is accelerated under the effect of 200 V p.d., its kinetic energy = ...................
  • 1.6 × 10–17 J
  • 3.2 × 10–17 J
  • 4.8 × 10–17 J
  • 6.4 × 10–17 J
In quantum mechanics, a particle.......................
  • can be regarded as group of harmonic waves.
  • can be regarded as a single wave of definite wavelength only
  • Can be regarded as only a pair of two harmonic waves
  • is a point-like object with mass.
The de-Broglie wavelength of a proton and α - particle is same. The ratio of their velocities will be.............. (α - particle is the He-nucleus, having two protons and two neutrons. Thus, its mass Mα = 4mp where mp is the mass of the proton.)
  • 1 : 4
  • 1 : 2
  • 2 : 1
  • 4 : 1
The de-Broglie wavelength associated with a particle with rest mass 0 m and moving with speed of light in vacuum is..................

  • Physics-Dual Nature of Radiation and Matter-67581.png
  • 0
  • ∞

  • Physics-Dual Nature of Radiation and Matter-67582.png
A proton and electron are lying in a box having unpenetrable walls, the ratio of uncertainty in their velocities are........( me = mass of electron and mp = mass of proton.)

  • Physics-Dual Nature of Radiation and Matter-67584.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67585.png

  • Physics-Dual Nature of Radiation and Matter-67586.png

  • Physics-Dual Nature of Radiation and Matter-67587.png
Photons of energy 1 eV and 2.5 ev successively illuminate a metal, whose work function is 0.5 eV, the ratio of maximum speed of emitted electron is..........................
  • 1 : 2
  • 2 : 1
  • 3 : 1
  • 1 : 3
The uncertainty in position of a particle is same as its de-Broglie wavelength, uncertainty in its momentum is.......................

  • Physics-Dual Nature of Radiation and Matter-67589.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67590.png

  • Physics-Dual Nature of Radiation and Matter-67591.png

  • Physics-Dual Nature of Radiation and Matter-67592.png
Wavelength of an electron having energy 10 keV is....... Å
  • 0.12
  • 1.2
  • 12
  • 120
Wavelength λA and λB are incident on two identical metal plates and photo electrons are emitted. If λa = 2λB , the maximum kinetic energy of photo electrons is................

  • Physics-Dual Nature of Radiation and Matter-67595.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67596.png

  • Physics-Dual Nature of Radiation and Matter-67597.png

  • Physics-Dual Nature of Radiation and Matter-67598.png
The de-Broglie wave length of a particle having velocity of 2.25 × 108 ms–1, is the same value of a photon wavelength, then the ratio of kinetic energy and photon energy of the particle is ......(c = 3 × 108 ms–1 )

  • Physics-Dual Nature of Radiation and Matter-67600.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67601.png

  • Physics-Dual Nature of Radiation and Matter-67602.png

  • Physics-Dual Nature of Radiation and Matter-67603.png
The ration of de - Begli wavelengths of molecules of hydrogen and helium which are at temperature 27o and 127oC respectively is...................

  • Physics-Dual Nature of Radiation and Matter-67605.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67606.png

  • Physics-Dual Nature of Radiation and Matter-67607.png
  • 1
A photon, an electron and a uranium nucleus all have same wavelength. The one with the most energy..................
  • is the photon
  • is the electron
  • is the uranium nucleus
  • depends upon the wavelength and properties of the particle.
A light of frequency 1.5 times the threshold frequency is incident on photo-sensitive material. If the frequency is halved and intensity is doubled, the photoelectric current becomes....................
  • zero
  • doubled
  • quadrupled
  • halved
An electron with rest mass m0 moves with a speed of 0.8 C. Its mass, when it moves with this speed is...............
  • m0
  • 2)
    Physics-Dual Nature of Radiation and Matter-67610.png

  • Physics-Dual Nature of Radiation and Matter-67611.png

  • Physics-Dual Nature of Radiation and Matter-67612.png
The cathode of a photoelectric cell is changed such that the work function changes from W1 to w2 (W1 >W2) . If the currents before and after change are I1 and I2 , all other conditions remaining unchanged, then assuming hf > W2 .............
  • I1 = I2
  • I1 < I2
  • I1 > I2
  • I1 < I2 < 2I1
The mass of a particle is 400 times than that of an electron and charge is double. The particle is accelerated by 5V. Initially the particle remained at rest, then its final kinetic energy is.................
  • 5 eV
  • 10 eV
  • 100 eV
  • 2000 eV
The work function of a metal is 1 eV. Light of wavelength 3000 Å is incident on this metal surface. The maximum velocity of emitted photo election will be..................
  • 10 ms–1
  • 103 ms–1
  • 104 ms–1
  • 106 ms–1
The work function for tungsten and sodium are 4.5 eV and 2.3 eV respectively. If the threshold wavelength λo for sodium is 5460 Å the value of λo for tungsten is...
  • 528 Å
  • 2791 Å
  • 5893 Å
  • 10683 Å
In the Davission and Germer\'s experiment the filament of electron gun is coated with.........
  • Cotton
  • BaO
  • Oil
  • FeO
Suppose ψ(x, y, z) represents a particle in three dimensional space, then probility of finding the particle in the unit volume at a given point x,y,z is .........
  • inversely proportional to ψ(x, y, z)
  • directly proportional ψ *
  • directly proportional to | ψ ψ *|
  • inversely proportional to | ψ ψ *|
Select the correct statement from the following
  • Radiantion and matter (particles) may not exhibit both the wave nature and particle nature simultaneously at the some moment.
  • At some moment electromagnetic waves get divided in to small pieces named particles
  • In a given circumstance a particle at one moment behaves like particle and the at the next moment as wave and so on
  • Each microscopic particle is envloped by a wave
In which of the following phenomena the photon picture is required ?
  • Energy distribution in black body radiation
  • Compton scattering
  • Photoelectric effect
  • None of these
Two identical detect 25 and 16 photons per second as shown in the Fig. ...... the ratio of the amplitudes of these light waves.
Physics-Dual Nature of Radiation and Matter-67616.png

  • Physics-Dual Nature of Radiation and Matter-67617.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67618.png

  • Physics-Dual Nature of Radiation and Matter-67619.png

  • Physics-Dual Nature of Radiation and Matter-67620.png
Calculate the energy of a photon of radian wavelength 6000 Å in eV.
  • 20.6 eV
  • 2.06 eV
  • 1.03 eV
  • 4.12 eV

Physics-Dual Nature of Radiation and Matter-67623.png
  • 4π × 1020
  • 1.51 × 1020
  • 16π2 × 1019

  • Physics-Dual Nature of Radiation and Matter-67624.png
The work function of metal is 5.3 eV. What is threshold frequency ?
  • 1.3 × 1015 Hz
  • 3.1 × 1015 Hz
  • 3.1 × 1045 Hz
  • 1.3 × 1045 Hz
An electron moving with velocity 0.6c, then de-brogly wavelength associated with is...........
(rest mars of electron, m0 = 9.1 × 10–31 K/s, h = 6.63 × 10–31 Js)
  • 3.24 × 10–12 m
  • 32.4 × 10–12 m
  • 320 × 10–12 m
  • 3.29 × 10–12 m
In an experiment to determine photoelectric characteristics for a metal the intensity of radiation is kept constant. St rating with threshold frequency. Now, frequency of incident radiation is increased. It is observed that ........
  • the nuber of photoelectrons increases
  • the energy of photoelectrons decreases
  • the number of photoelectrons decreases
  • the energy of photo electrons increases
Valance electrons in metals .......
  • are completely free to move anywhere in metal
  • move in the space according to their wave function inside the metal
  • can move outside metal also
  • never escape from metal
Rayleigh and jeans regarded the black body radiations as

  • Physics-Dual Nature of Radiation and Matter-67627.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67628.png

  • Physics-Dual Nature of Radiation and Matter-67629.png

  • Physics-Dual Nature of Radiation and Matter-67630.png
According to Rayleigh and Jeans the black body radiation in the cavity is system of
  • progressive electromagnetic waves
  • standing electromagnetic waves
  • electromagnetic waves of discrete frequencies
  • standing waves in lattice

Physics-Dual Nature of Radiation and Matter-67631.png
  • 150 Kms–1
  • 200 Kms–1
  • 500 Kms–1
  • 250 Kms–1
Radius of a nucleus 2 × 10–15 m . If we imagine an electron inside the nucleus then energy of electron will be = ......... MeV.
me = 9.1 × 10–31 kg, h = 6.6 × 10–34 Js
  • 6.98 × 103
  • 8.94 × 103
  • 4.98 × 103
  • 9.48 × 103
2mW light of wave length 4400 Å is incident on photo sensitive surface of Cs. If quantum efficiency is 0.5 %, what will be the value of photoelectric current ?
  • 1.56 μA
  • 2.56 μA
  • 4.56 μA
  • 3.56 μA
A proton, a deutron and an a-particle having the same momentum, enters a region of uniform electric field between the parallel plates of a capacitor. The electric field is perpendicular to the initial path of the particles. Then the ratio of deflections suffered by them is
Physics-Dual Nature of Radiation and Matter-67634.png
  • 1 : 2 : 8
  • 1 : 2 : 4
  • 1 : 1 : 2
  • None of these
In the following agreement y = 1.0 mm, d = 0.24 mm and D = 1.2 m. The work function of the material of the emitter is 2.2 eV. The stopping potential V needed to stop the photon is ..........
Physics-Dual Nature of Radiation and Matter-67636.png
  • 0.9 V
  • 0.5 V
  • 0.1 V
  • 0.4 V
Assertion : Stopping potential is a measure of K.E. of photo-electrons.
Reason : W = eVs = 1/2 mv2 = K. E
  • Both Assertion and Reason are true and Reason is correct explanation of Assertion.
  • Both Assertion and Reason are true, but Reason is not correct explanation of Assertion.
  • Assertion is true but the Reason is false.
  • Both Assertion and Reason is false.
Assertion : Metals like Na or K, emit electrons even when visible lights fall on them .
Reason : This is because their work function is low.
  • Both Assertion and Reason are true and Reason is correct explanation of Assertion
  • Both Assertion and Reason are true, but Reason is not correct explanation of Assertion.
  • Assertion is true but the Reason is false
  • Both Assertion and Reason is false.
Assertion : The de Broglie wavelength of an electron accelerated through 941 volts is 0.4 Å
Reason : Higher the acceleration potentials of electron, smaller is the de Broglie wavelength.
  • Both Assertion and Reason are true and Reason is correct explanation of Assertion
  • Both Assertion and Reason are true, but Reason is not correct explanation of Assertion.
  • Assertion is true but the Reason is false.
  • Both Assertion and Reason is false.
Threshold - Frequency is equal to = ................ × 1014 Hz.
  • 4.0
  • 4.2
  • 8.0
  • 8.4
An electron is accelerated under a potential difference of 64 V, the de Broglie wave length associated with electron is = ............. Å
(Use charge of electron = 1.6 × 10–19 C, C = 9.1 × 10–31 Kg, mass of electron h = 6.623 × 10–34 J.sec))
  • 4.54
  • 3.53
  • 2.53
  • 1.534
A α particle and proton has same K.E. The ratio of de Broglie wavelength of a α - particle and proton is....

  • Physics-Dual Nature of Radiation and Matter-67640.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67641.png
  • 1
  • 2
If α particle and proton have same momenta, the ratio of de Broglie wavelength of α -particle and proton is.....

  • Physics-Dual Nature of Radiation and Matter-67643.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67644.png
  • 1
  • 2
If α - particle and proton have same velocities, the ratio of de Broglie wavelength of α -particle and proton is ....

  • Physics-Dual Nature of Radiation and Matter-67646.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67647.png
  • 1
  • 2
If α - particle and proton are accelerated through the same potential difference, then the ratio of de Brogile wavelength of α - particle and proton is ........

  • Physics-Dual Nature of Radiation and Matter-67648.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67649.png

  • Physics-Dual Nature of Radiation and Matter-67650.png

  • Physics-Dual Nature of Radiation and Matter-67651.png
Read the paragraph carefully and select the proper choice from given multiple choices. According to Einstein when a photon of light of frequency f or wavelength λ is incident on a photo sensitive metal surface of work function Ø . Where Ø < hf (here h is Plank\'s constant) then the emission of photo-electrons place takes place. The maximum K.E. of emitted photo electrons is given by Kmax = hf – Ø . If the there hold frequency of metal is f0 then hf0 = Ø .
A metal of work function 3.3 eV is illuminated by light of wave length 300 nm. The maximum K.E > of photo-electrons is  ........eV. (h = 6.6 × 10–34 J.sec)
  • 0.825
  • 0.413
  • 1.32
  • 1.65
Gases begin to conduct electricity at low pressure because
  • At low pressure, gases turn to plasma
  • Colliding electrons can acquire higher kinetic energy due to increased mean free path leading to ionisation of atoms
  • Atoms break up into electrons and protons
  • The electrons in atoms can move freely at low pressure
0:0:1


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