JEE Questions for Physics Dual Nature Of Radiation And Matter Quiz 20 - MCQExams.com

Assertion X-rays cannot be diffracted by means of grating.
Reason X-rays do not obey Bragg\'s law.
  • 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 X-rays can penetrate through the flesh but not through the bones.
Reason The penetrating power of X-rays depends on voltage.
  • 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 Intensity of X-rays can be controlled by adjusting the filament current and voltage.
Reason The intensity of X-rays does not depend on number of X-ray photons emitted per second from the target.
  • 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 Soft and hard X-rays differ in frequency as well as velocity.
Reason The penetrating power of hard X-rays is more than the penetrating power of soft 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 Penetrating power of X-rays increases with the increasing the wavelength.
Reason The penetrating power of X-rays increases with the frequency 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 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.
  • 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 photo electrons but there is no such emission with yellow colour light. Which one of the colour can produce emission of photo electrons?
  • Orange
  • Red
  • Indigo
  • None of these
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-68475.png
  • Increasing, increasing
  • Increasing, decreasing
  • Decreasing, same
  • Same, Same
The figure shows different graphs between stopping potential (V0) and frequency (v) for photosensitive surface of cesium, potassium, sodium and lithium. The plots are parallel. Correct ranking of the targets according to their work function greatest first will be
Physics-Dual Nature of Radiation and Matter-68476.png
  • (i) > (ii) > (iii) > (iv)
  • (i) > (ii) > (iii) > (iv)
  • (iv) > (iii) > (ii) < (i)
  • (i) = (iii) > (ii) = (iv)
The Kα X-rays arising from a cobalt (z =targethave 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

Physics-Dual Nature of Radiation and Matter-68477.png
  • 1.8 eV
  • 2.1 eV
  • 4.5 eV
  • 3.3 eV
Five elements A, B, C, D and E have work functions 1.2 eV, 2.4 eV, 3.6 eV, 4.8 eV and 6 eV respectively. If light of wavelength 4000 Å is allowed to fall on these elements, then photo electrons are emitted by
  • A, B and C
  • A, B, C, D and E
  • A and B
  • Only E
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

  • Physics-Dual Nature of Radiation and Matter-68478.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68479.png

  • Physics-Dual Nature of Radiation and Matter-68480.png

  • Physics-Dual Nature of Radiation and Matter-68481.png
If the momentum of an electron is changed by ∆p, thenthe 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-68482.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68483.png

  • Physics-Dual Nature of Radiation and Matter-68484.png

  • Physics-Dual Nature of Radiation and Matter-68485.png

Physics-Dual Nature of Radiation and Matter-68486.png
  • 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-68487.png
  • 1.22 Å
  • 1.75 Å
  • 2 Å
  • None of these
If the potential difference between the anode and cathode of the X-ray tube is increase
Physics-Dual Nature of Radiation and Matter-68488.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 increase
  • (b) and (c) both are correct
Photoelectric effect supports quantum nature of light, because
I. there is minimum frequency of light below which no photoelectrons are emitted.
II. electric charge of photoelectrons is quantised.
III. maximum kinetic energy of photoelectrons depends only on the frequency of light and not on its intensity.
IV. even when metal surface is faintly illuminated the photoelectrons leave the surface immediately.
  • I, II and III
  • I, II and IV
  • II, III and IV
  • I, III and IV
An important spectral emission line has a wavelength of 21 cm. The corresponding photon energy is (h = 6.62 × 10–34 Js and c = 3 × 108 ms–1)

  • Physics-Dual Nature of Radiation and Matter-68489.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68490.png

  • Physics-Dual Nature of Radiation and Matter-68491.png

  • Physics-Dual Nature of Radiation and Matter-68492.png
X – rays are used to irradiate sodium and copper surfaces in two separate experiments and stopping potential determind. This stopping potential is
  • equal in both cases
  • greater for sodium
  • greater for copper
  • infinite in both cases
A proton and an x-particle are passed through same potential difference. If their initial velocity is zero, the ratio of their de Broglie\'s wavelength after getting accelerated is...................
  • 1 : 2
  • 1 : 2
  • 2 : 1
  • 2√2 : 1
Photocell is a device to
  • store photons
  • measure light intensity
  • convert photon energy into mechanical energy
  • store electrical energy for replacing storage batteries.
An electron and proton are moving with the same speed. Mass of proton =1836 times mass of electron. The ration of their de – Broglie wavelengths will be
  • 1
  • 1836
  • 1/1836
  • 918
The de – Broglie wavelength of a neutron at 927o C is λ . What will be its wavelength at 27oC ?
  • λ /2
  • λ /4
  • 4λ
  • 2λ
The correctness of velocity of an electron moving with velocity 50ms-1 is 0.005 %. The accuracy with which its position can be measured will be

  • Physics-Dual Nature of Radiation and Matter-68497.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68498.png

  • Physics-Dual Nature of Radiation and Matter-68499.png

  • Physics-Dual Nature of Radiation and Matter-68500.png
An X – ray tube is operated at 20kV. The maximum speed of electrons striking the anticathode will be

  • Physics-Dual Nature of Radiation and Matter-68502.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68503.png

  • Physics-Dual Nature of Radiation and Matter-68504.png

  • Physics-Dual Nature of Radiation and Matter-68505.png
When X – rays of wavelength 1Å passes through a gold foil of thikness 2.303 mm , then their intensity reduces to half. The coefficient of absorption for gold (in mm-1) will be A passes through a gold foil of thikness
  • 0.2
  • 0.3
  • 0.4
  • 0.5
An X – rays tube is operated at 50 kV, produce heat at the target at the rate of 796 watt. If 0.5% energy of incident electrons is converted into X –rays,then the number of electrons striking the target per second will be
  • 1019
  • 1018
  • 1017
  • 1016
An X – ray tube is operating at 15 kv. The lower limit of the wavelength of X – rays produced is

  • Physics-Dual Nature of Radiation and Matter-68509.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68510.png

  • Physics-Dual Nature of Radiation and Matter-68511.png

  • Physics-Dual Nature of Radiation and Matter-68512.png
Light of wavelength 5000Å falls on a sensitive plate with photoelectric work function of 1.9 eV. The kinetic energy of the photoelectron emitted will be
  • 0.58 eV
  • 2.48 eV
  • 1.24 eV
  • 1.16 eV
Two radiations containing photons of energy twice and five times the work function of a metal are incident successively on the metal surface. The ratio of the maximum velocities of the emitted electrons in the two cases will be
  • 1:3
  • 1:4
  • 1:2
  • 1:1
Electron with energy 80 ke V are incident on the tungsten target of an X – ray tube. K shell electrons of tungsten have –72.5 Ke V energy .X –rays emitted by the tube contain only
  • a continuously X – rays spectrum (Bremsstrahlung) with a minimum wavelength of 0.155Å
  • a continuous X – ray spectrum (Bremsstrahlung) with all wavelengths
  • the characteristic X – ray spectrum of tunsten
  • a continuously X – ray spectrum (Bremsstrahlung) with a minimum wavelength of o tunsten 0.155Å and the characteristic X – ray spectrum of
An ionised gas contains both positive and negative ions. If it is subjected simultaneously to an electric field along the +x direction and a magnetic field along the +z direction, then
  • positive ions deflect towards + y direction and negative ions deflect towards –y direction
  • all ions deflect towards + y direction
  • all ions deflect towards –y direction
  • positive ions deflect towards –y direction and negative ions towards +y direction
Find the kinetic energy of the photoelectrons emitted when light of wavelength 4000Å is incident on a metal of work function 2eV (find approximately)
  • 0.5eV
  • 1.1 eV
  • 2.5 eV
  • 3 eV
If the potential difference applied across X – ray tube is V volt, then approximately minimum wavelength of the emitted X – rays will be

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  • 2)
    Physics-Dual Nature of Radiation and Matter-68520.png

  • Physics-Dual Nature of Radiation and Matter-68521.png

  • Physics-Dual Nature of Radiation and Matter-68522.png
A proton and an alpha particle are accelerated through a potential difference of 100 V. The ratio of the wavelength associated with the proton to that associated with an alpha particle is

  • Physics-Dual Nature of Radiation and Matter-68524.png
  • 2

  • Physics-Dual Nature of Radiation and Matter-68525.png

  • Physics-Dual Nature of Radiation and Matter-68526.png
Two identical photo – cathodes receive light of frequencies f1 and f2. If the velocities of the photoelectrons ( of mass m) coming out are respectively v1 and v2,then.

  • Physics-Dual Nature of Radiation and Matter-68528.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68529.png

  • Physics-Dual Nature of Radiation and Matter-68530.png

  • Physics-Dual Nature of Radiation and Matter-68531.png
An X – ray tube is operated at a constant potential difference and it is required to get X – rays of wavelength not less than 0.2 nano-meter. Then the potential difference in kilo volt is (h = 6.63 × 10–34 Js ; e = 1.6 × 10-19 C, c = 3 × 108 m/s)
  • 24.8
  • 12.4
  • 6.2
  • 3.1
The energy of a photon is equal to the kinetic energy of proton.The energy of a photon is E. Let λ1 be the de- Brogile wavelength of the proton and λ2 be the wavelength of the photon. The ratio λ1/λ2 is proportional to
  • Eo
  • E1/2
  • E-1
  • E-2
An electron and a proton are accelerated through the same potential difference. The ratio of their de – Broglie wavelength will be

  • Physics-Dual Nature of Radiation and Matter-68535.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68536.png

  • Physics-Dual Nature of Radiation and Matter-68537.png
  • 1
If the kinetic energy of a free electron doubles, its de Broglie wavelength changes by the factor

  • Physics-Dual Nature of Radiation and Matter-68539.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68540.png
  • 2

  • Physics-Dual Nature of Radiation and Matter-68541.png
An element with atomic number Z=11 emits kα X – ray of wavelength λ . The atomic number of element which emits Kα X – ray of wavelength 4λ.
  • 6
  • 4
  • 11
  • 44
A small metal plate (work function = 1.17 eV) is placed at a distance of 2 m from a monochromatic light source of wavelength 4.8 × 10−7 m and power 20 watt. The light falls normally on the plate. The number of photons striking the metal plate per second per sq metre area will be

  • Physics-Dual Nature of Radiation and Matter-68544.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68545.png

  • Physics-Dual Nature of Radiation and Matter-68546.png

  • Physics-Dual Nature of Radiation and Matter-68547.png
The minimum light intensity that can be perceived by the eye is about 10-10 w/m2. The number of photons of wavelength 5.6 × 10–7 m that must enter the pupil of area 10–4 m2 per second, for vision is approximately equal to (h = 6.6 × 10-34 Js)

  • Physics-Dual Nature of Radiation and Matter-68549.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68550.png

  • Physics-Dual Nature of Radiation and Matter-68551.png

  • Physics-Dual Nature of Radiation and Matter-68552.png
The earth receives 8.4 J/minute/m2 energy from the sun. If the solar energy in 10 × 104 m2 area is concentrated in a cup filled with 100 g water at 0oC, in how much time the water will boil
  • 3 sec
  • 6 sec
  • 9 sec
  • 12 sec
A photon and electron have same de – Broglie wavelength. Given that υ is the speed of electron and c is the velocity of light. Ee, Ep are the kinetic energy of electron and photon respectively. pe, ph are the momentum of electron and photon respectively. Then which of the following relation is correct.

  • Physics-Dual Nature of Radiation and Matter-68555.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-68556.png

  • Physics-Dual Nature of Radiation and Matter-68557.png

  • Physics-Dual Nature of Radiation and Matter-68558.png
When electric bulb having 100 W efficiency emits photon having wavelength 410 mm every second, numbers of photons will be......(h = 6 × 10–34 J.s, c = 3 × 108 ms–1 )
  • 100
  • 1000
  • 3 × 1020
  • 3 × 1018
Photocell cell is enlightened by small bright source 1 m away. If the same light source is placed 1/2 m away, number of electrons emitted by cathode will be............
  • increases twice
  • decreases twice
  • increases 4 times
  • decreases 4 times
0:0:1


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