JEE Questions for Physics Dual Nature Of Radiation And Matter Quiz 15 - MCQExams.com

Assertion X-rays are used for studying the structure of crystals.
Reason The distance between the atoms of crystals is of the order of wavelength of X-rays.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true
Assertion The phenomenon of X-ray production is basically inverse of photoelectric effect.
Reason X-rays are electromagnetic waves.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion
  • If Assertion is true but Reason is false
  • f the Assertion and Reason both are false
  • If Assertion is false but Reason is true
Assertion Davisson-Germer experiment established the wave nature of electrons.
Reason If electrons have wave nature, they can interfere and show diffraction.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Which of the following metal thermionically emits an electron at a relatively lowest temperature among them?]
  • Platinum
  • Copper
  • Aluminum
  • Molybdenum
When green light is incident on the surface of metal, it emits photoelectrons but there is no such emission with yellow colour light. Which one of the colour can produce emission of photoelectrons?
  • Orange
  • Red
  • Indigo
  • None of the above
An electron is moving through a field. It is moving (i) opposite an electric field (ii) perpendicular to a magnetic field as shown. For each situation the de-Broglie wavelength of electron
Physics-Dual Nature of Radiation and Matter-68108.png
  • Increasing, increasing
  • Increasing, decreasing
  • Decreasing, same
  • Same, Same
The figure shows different graphs between stopping potential (V0) and frequency (v) for photosensitive plots are parallel. Correct ranking of the targets according to their work function greatest first will be
Physics-Dual Nature of Radiation and Matter-68110.png
  • (i) > (ii) > (iii) > (iv)
  • (i) > (iii) > (ii) > (iv)
  • (iv) > (iii) > (ii) > (i)
  • (i) = (iii) > (ii) = (iv)
The Kα X-rays arising from a cobalt (z =target have a wavelength of 179 pm. The Kα X-rays arising from a nickel target (z =is
  • > 179 pm
  • < 179 pm
  • = 179 pm
  • None of these
If a voltage applied to an X-ray tube is increased to 1.5 times the minimum wavelength (λmin) of an X-ray continuous spectrum shifts by ∆λ = 26 pm. The initial voltage applied to the tube is
  • ≈10 kV
  • ≈16 kV
  • ≈ 50 kV
  • ≈ 75 kV

Physics-Dual Nature of Radiation and Matter-68114.png
  • 1.8 eV
  • 2.1 eV
  • 4.5 eV
  • 3.3 eV
If light of wavelength λ1 is allowed to fall on a metal, then kinetic energy of photoelectrons emitted is E1. If wavelength of light changes to λ2 then kinetic energy of electrons changes to E2. Then work function of the metal is

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  • 2)
    Physics-Dual Nature of Radiation and Matter-68118.png

  • Physics-Dual Nature of Radiation and Matter-68119.png

  • Physics-Dual Nature of Radiation and Matter-68120.png
If maximum velocity with which an electron can be emitted from a photo cell is 4 × 108 cm/s, the stopping potential is (mass of electron = 9 × 10–31 kg)
  • 30 volt
  • 45 volt
  • 59 volt
  • Information is insufficient
The collector plate in an experiment on photoelectric effect is kept vertically above the emitter plate. Light source is put on and a saturation photo current is recorded. An electric field is switched on which has a vertically downward direction
  • The photo current will increase
  • The kinetic energy of the electrons will increase
  • The stopping potential will decrease
  • The threshold wavelength will decrease
If the momentum of an electron is charged by ∆p, then the de-Broglie wavelength associated with it changes by 0.50% . The initial momentum of the electron will be

  • Physics-Dual Nature of Radiation and Matter-68124.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68125.png
  • 199 ∆p
  • 400 ∆p
If 10000 V is applied across an X-ray tube, what will be the ratio of de-Broglie wavelength of the incident electrons to the shortest wavelength of X-ray produced (e/m for electron is 1.8 × 1011c kg–1)
  • 1
  • 0.1
  • 0.2
  • 0.3
Two large parallel plates are connected with the terminal of 100 V power supply. These plates have a fine hole at the centre. An electron having energy 200 eV is so directed that it passes through the holes. When it comes out it\'s de-Broglie wavelength is
Physics-Dual Nature of Radiation and Matter-68128.png
  • 1.22 Å
  • 1.75 Å
  • 2 Å
  • None of the above
If the potential difference between the anode and cathode of the X-ray tube is increase
Physics-Dual Nature of Radiation and Matter-68130.png
  • The peaks at R and S would move to shorter wavelength
  • The peaks at R and S would remain at the same wavelength
  • The cut off wavelength at P would decrease
  • (b) and (c) both are correct
Monochromatic light of wavelength 3000 Å is incident on a surface area 4 cm2. If intensity of light is 150 mW/m2, then rate at which photons strike the target is
  • 3 × 1010/s
  • 9 × 1013/s
  • 7 × 1015/s
  • 6 × 1019/s
For characteristic X-ray of some material
  • E (Kγ) < E(Kβ)< E(Kα)
  • E(Kα)α)α)
  • λ(Kγ) < λ(Kβ < λ (Kα)
  • λ (Mα ) < λ (Lα) < λ (Kα)
The maximum velocity of electrons emitted from a metal surface is V when frequency of light falling on it is f. The maximum velocity when frequency becomes 4f is
  • 2 V
  • > 2 V
  • < 2 V
  • Between 2 V and 4 V
In the phenomenon of electron discharge through gases at low pressure, the coloured glow in the tube appears as a result of
  • Collisions between the charged particles emitted from the cathode and the atoms of the gas
  • Collision between different electrons of the atoms of the gas
  • Excitation of electrons in the atoms
  • Collision between the atoms of the gas
Which of the following law is used in the Millikan\'s method for the determination of charge?
  • Ampere's law
  • Stoke's law
  • Fleming's left hand rule
  • Fleming's right hand rule

Physics-Dual Nature of Radiation and Matter-68136.png
  • Rotation of e– clockwise and anticlockwise direction respectively
  • Rotation of e– anticlockwise and clockwise directions respectively
  • Rotation in any direction according to convention
  • None of the above
In Millikans oil drop experiment, a charged drop of mass 1.8 × 10–14 kg is stationary between its plates. The distance between its plates is 0.90 cm and potential difference is 2.0 kilo volts. The number of electrons onthe drop is
  • 500
  • 50
  • 5
  • 0
From the following, what charges can be present on oil drops in Millikan\'s experiment
(Here e is the electronic charge)
  • Zero, equal to the magnitude of charge on α–particle
  • 2e, 1.6 × 10–18 C
  • 1.6 × 10–19 C, 2.5 e
  • 1.5 e, e
In a discharge tube ionization of enclosed gas is produced due to collisions between
  • Photons and neutral atoms/molecules
  • Neutral gas atoms/molecules
  • Positive ions and neutral atoms/molecules
  • Negative electrons and neutral atoms/molecules
Cathode rays are similar to visible light rays as
  • They both can be deflected by electric and magnetic fields
  • They both have a definite magnitude of wavelength
  • They both can ionize a gas through which they pass
  • They both can expose a photographic plate
Which of the following devices makes use of the electrons to strike certain substances to produce fluorescence ?
  • Thermionic valve
  • Photoelectric cell
  • Cathode ray oscilloscope
  • Electron gun
The radius of the orbital of electron in the hydrogen atom is 0.5 Å. The speed of the electron is 2 ×106 m/s. Then the current in the loop due to the motion of the electron is
  • 1 mA
  • 1.5 mA
  • 2.5 mA
  • 1.5 × 10–2 mA
A metal plate gets heated when cathode rays strike against it due to
  • Kinetic energy of cathode rays
  • Potential energy of cathode rays
  • Linear velocity of cathode rays
  • Angular velocity of cathode rays
In Millikan\'s experiment, an oil drop having charge q gets stationary on applying a potential difference V in between two plates separated by a distance ‘d\'. The weight of the drop is

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  • 2)
    Physics-Dual Nature of Radiation and Matter-68142.png

  • Physics-Dual Nature of Radiation and Matter-68143.png

  • Physics-Dual Nature of Radiation and Matter-68144.png
Electron volt is a unit of
  • Potential
  • Charge
  • Power
  • Energy
Which of the following is not the property of a cathode ray?
  • It casts shadow
  • It produces heating effect
  • It produces fluroscence
  • It does not deflect in electric field
In Bainbridge mass spectrograph a potential difference of 1000 V is applied between two plates distant 1 cm apart and magnetic field B =1 T. The velocity of undeflected positive ions in m/s from the velocity selector is
  • 107 m/s
  • 104m/s
  • 105 m/s
  • 102 m/s
An electron is accelerated through a p.d. of 45.5 volt. The velocity acquired by it is (in ms–1)
  • 4 × 106
  • 4 × 104
  • 106
  • Zero
A cathode emits 1.8 × 1014 electrons per second, whenheated. When 400 V is applied to anode all the emitted electrons reach the anode. The charge on electron is 1.6 × 10–19 C. The maximum anode current is
  • 2.7 µA
  • 29µA
  • 72 µA
  • 29 mA
Order of q/m ratio of proton, α–particle and electron is
  • e > p > a
  • p > a > e
  • e > a > p
  • None of these
An electron initially at rest, is accelerated through a potential difference of 200 volt, so that it acquires a velocity 8.4 × 106 m/s. The value of e/m of electron will be
  • 2.76 × 1012 C/kg
  • 1.76 × 1011 C/kg
  • 0.76 × 1012 C/kg
  • None of these
An oil drop carrying a charge q has a mass m kg. It is falling freely in air with terminal speed v. The electric field required to make the drop more upwards with thesame speed is

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  • 2)
    Physics-Dual Nature of Radiation and Matter-68152.png

  • Physics-Dual Nature of Radiation and Matter-68153.png

  • Physics-Dual Nature of Radiation and Matter-68154.png
Positive rays consists of
  • Electrons
  • Neutrons
  • Positive ions
  • Electro magnetic waves
O++,C+, He++and H+ ions are projected on the photographic plate with same velocity in a mass spectrograph. Which one will strike farthest
  • O++
  • C+
  • He++

  • Physics-Dual Nature of Radiation and Matter-68156.png
A beam of cathode rays is subjected to crossed Electric (E) and Magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific chargeof the cathode rays is given by

  • Physics-Dual Nature of Radiation and Matter-68158.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68159.png

  • Physics-Dual Nature of Radiation and Matter-68160.png

  • Physics-Dual Nature of Radiation and Matter-68161.png
Positive rays are very identical to
  • α–particle rays
  • β–rays
  • γ–rays
  • None of these
The frequency of a photon, having energy 100 eV is (h = 6.6 × 10–34 J-s)
  • 2.42 × 1026 Hz
  • 2.42 × 1016 Hz
  • 2.42 × 1012 Hz
  • 2.42 × 109 Hz
The mass of a photo electron is
  • 9.1 × 10–27 kg
  • 9.1 × 10–29 kg
  • 9.1 × 10–31kg
  • 9.1 × 10–34kg
A charged oil drop of mass 2.5 × 10–7 kg is in space between the two plates, each of area 2 × 10–2 m2 of a parallel plate capacitor. When the upper plate has a charge of 5 × 10–7 C and the lower plate has an equal negative charge, the oil remains stationary. The charge of the oil drop is (Take g = 10 m /s2)
  • 9 × 10–1 C
  • 9 × 10–6 C
  • 8.85 × 10–13 C
  • 1.8 × 10–14 C
A particle which has zero rest mass and non-zero energy and momentum, must travel with a speed
  • Equal to c, the speed of light in vacuum
  • Greater than c
  • Less than c
  • Tending to infinity
A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of 3 × 106ms–1. The velocity of the particle is
(Mass of electron = 9.1 × 10–31 kg)
  • 3 × 10–31ms–1
  • 2.7 × 10–21ms–1
  • 2.7 × 10–18ms–1
  • 9 × 10–2ms–1
The de-Broglie wavelength λ associated with an kinetic energy E is given by the expression

  • Physics-Dual Nature of Radiation and Matter-68166.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68167.png

  • Physics-Dual Nature of Radiation and Matter-68168.png

  • Physics-Dual Nature of Radiation and Matter-68169.png
What is the de-Broglie wavelength of the α–particle accelerated through a potential difference V?

  • Physics-Dual Nature of Radiation and Matter-68177.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68178.png

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  • Physics-Dual Nature of Radiation and Matter-68180.png
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