JEE Questions for Physics Dual Nature Of Radiation And Matter Quiz 18 - MCQExams.com

A metal block is exposed to beams of X-ray of different wavelengths X-rays of which wavelength penetrate most
  • 2 Å
  • 4 Å
  • 6 Å
  • 8 Å
Given below is a list of electromagnetic spectrum and its mode of production. Which one does not match?
  • Gamma rays-Radioactive of the nucleus
  • Ultraviolet-Magnetron value
  • Infrared Vibration of atoms and molecules
  • Radiowave-Rapid acceleration and deceleration of electrons in conducting wires
Mosley\'s law relates the frequencies of line X-rays with the following characteristics of the target element
  • Its density
  • Its atomic weight
  • Its atomic number
  • Interplaner spacing of the atomic planes
A beam of 35.0 keV electrons strikes a molybdenum target, generating the X-rays. What is the cut-off wavelength?
  • 35.5 pm
  • 40.0 pm
  • 15.95 pm
  • 18.2 pm
X-rays and y-rays of the same energies may be distinguished by
  • Their velocity
  • Their ionizing power
  • Their intensity
  • Method of production
The wavelength of Kα line in copper is 1.54 Å. The ionization energy of K electron in copper in Joule is
  • 11.2 × 10–27
  • 12.9 × 10–16
  • 1.7 × 10–18
  • 10 × 10–16
The X-ray beam corning from an X-ray tube will be
  • Monochromatic
  • Having all wavelengths smaller than a certain maximum wavelength
  • Having all wavelengths larger than a certain minimum wavelength
  • Having all wavelengths lying between a minimum and a maximum wavelength
In X-ray spectrum wavelength λ of line Kα depends onatomic number Z as

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An X-ray tube with a copper target emits Kα line of wavelength 1.50 A. What should be the minimum voltage through which electrons are to be accelerated to produce this wavelength of X-rays?
(h = 6.63 × 10–34 J-s, c = 3 × 108 m/s)
  • 8280 V
  • 828 V
  • 82800 V
  • 8.28 V
If V be the accelerating voltage, then the maximum frequency of continuous X-rays is given by

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The minimum wavelength of X-rays produced by electrons accelerated by a potential difference of volts is equal to

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The potential difference applied to an X-ray tube is increased. As result, in the emitted radiation
  • The intensity increases
  • The minimum wavelength increases
  • The intensity decreases
  • The minimum wavelength decreases
A potential difference of 42,000 volts is used in an X-ray tube to accelerate electrons. The maximum frequency of the X-radiations produced is
(leV = 1.6 × 10–19 J and h = 6.63 × 10–34 J-s)
  • 1019 Hz
  • 1018 Hz
  • 1016 Hz
  • 1020 Hz
Which of the following is accompanied by the characteristic X-ray emission ?
  • α–particle emission
  • Electron emission
  • Position emission
  • K-electron capture
X-ray beam can be deflected by
  • Magnetic field
  • Electric field
  • Both (a) and (b)
  • None of these
X-rays are produced due to
  • Break up of molecules
  • Changing in atomic energy level
  • Changing in nuclear energy level
  • Radioactive disintegration
Solid targets of different elements are bombarded by highly energetic electron beams. The frequency (f) of the characteristic X-rays emitted from different targetsvaries with atomic number Z as

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In vacuum an electron of energy 10 keV hits tungsten target, then emitted radiation will be
  • Cathode rays
  • X-rays
  • Infrared rays
  • Visible spectrum
Penetrating power of X-rays can be increased by
  • Increasing the potential difference between anode and cathode
  • Decreasing the potential difference between anode and cathode
  • Increasing the cathode filament current
  • Decreasing the cathode filament current
For the structural analysis of crystals, X-rays are used because
  • X-rays have wavelength of the order of interatomic spacing
  • X-rays are highly penetrating radiations
  • Wavelength of X-rays is of the order of nuclear size
  • X-rays are coherent radiations
The essential distinction between X-rays and γ-rays is that
  • γ-rays have smaller wavelength than X-rays
  • γ-rays emanate from nucleus while X-rays emanate from outer part of the atom
  • γ-rays have greater ionizing power than X-rays
  • γ-rays are more penetrating than X-rays
The wavelength of X-rays decreases, when
  • Temperature of target is increased
  • Intensity of electron beam is increased
  • K.E. of electrons striking the target is increased
  • K.E. of electrons striking the target is decreased
What determines the hardness of the X-rays obtained from the Coolige tube ?
  • Current in the filament
  • Pressure of air in the tube
  • Nature of target
  • Potential difference between cathode and target
On increasing the number of electrons striking the anode of an X-rays tube, which one of the following parameters of the resulting X-rays would increase?
  • Penetration power
  • Frequency
  • Wavelength
  • Intensity
Hard X-rays for the study of fractures in bones should have a minimum wavelength of 10–11m. The accelerating voltage for electrons in X-ray machineshould be
  • < 124.2 kV
  • > 124.2 kV
  • Between 60 kV and 70 kV
  • = 100 kV
If the voltage of X-ray tube is doubled, the intensity of X-rays will become
  • Half
  • Unchanged
  • Double
  • Four times
For the production of X-rays, the target should be made of
  • Steel
  • Copper
  • Aluminum
  • Tungsten
Intensity of X-rays depends upon the number of
  • Electrons
  • Protons
  • Neutrons
  • Positrons
When X-rays pass through a strong uniform magneticfield. Then they
  • Do not get deflected at all
  • Get deflected in the direction of the field
  • Get deflected in the direction opposite to the field
  • Get deflected in the direction perpendicular to the field
What is the difference between soft and hard X-rays?
  • Velocity
  • Intensity
  • Frequency
  • Polarization
The minimum wavelength of X-ray emitted by X-rays tube is 0.4125 Å. The accelerating voltage is
  • 30 kV
  • 50 kV
  • 80 kV
  • 60 kV
Characteristic X-rays are produced due to
  • Transfer of momentum in collision of electrons with target atoms
  • Transition of electrons from higher to lower electronic orbits in an atom
  • Heating of the target
  • Transfer of energy in collision of electrons with atoms in the target
X-rays when incident on a metal
  • Exert a force on it
  • Transfer energy to it
  • Transfer pressure to it
  • None of these
The minimum wavelength of X-rays produced in a coolidge tube operated at potential difference of 40 kV is
  • 0.31 Å
  • 3.1 Å
  • 31 Å
  • 311 Å
If the operating potential of an X-ray tube is 50 kV, thevelocity of X-rays coming out of it is
  • 4 × 104 m/s
  • 3 ×108 m/s
  • 108 m/s
  • 3 m/s
The nature of X-rays spectrum is
  • Continuous
  • Line
  • Continuous and line
  • None of the above
A 1 µA beam of protons with a cross-sectional area of 0.5 sq. mm is moving with a velocity of 3 × 104ms–1.Then charge density of beam is
  • 6.6 × 10–4 C/m3
  • 6.6 × 10–5 C/m3
  • 6.6 × 10–6 C/m3
  • None of the above
In the Davission and Germer experiment, the velocity of electrons emitted from the electron gun can beincreased by
  • Decreasing the potential difference between the anode and filament
  • Increasing the potential difference between the anode and filament
  • Increasing the filament current
  • Decreasing the filament current
A photon of 1.7 × 10–13 Joules is absorbed by amaterial under special circumstances. The correct statement is
  • Electrons of the atom of absorbed material will go the higher energy states
  • Electron and positron pair will be created
  • Only positron will be produced
  • Photoelectric effect will occur and electron will be produced
The maximum velocity of an electron emitted by light of wavelength X incident on the surface of a metal of work function ɸ, is
Where h = Planck\'s constant, m = mass of electron and c = speed of light.

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In a photoemissive cell with exciting wavelength λ, the fastest electron has speed v. If the exciting wavelength is changed to 3λ /4, the speed of the fastest emitted electron will be
  • v(3 /4)1/2
  • v(4 /3)1/2
  • Less than v(4 /4)1/2
  • Greater than v(4 /3)1/2
Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 of the incident light rays (v1> v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

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Work function of lithium and copper are respectively 2.3 eV and 4.0 eV. Which one of the metal will be useful for the photoelectric cell working with visible light
(h = 6.6 × 10–34 J-s, C = 3 × 108 m/s)
  • Lithium
  • Copper
  • Both
  • None of these
An X-ray pulse of wavelength 4.9 Å is sent through a section of Wilson cloud chamber containing a super saturated gas, and tracks of photo electron ejected from the gaseous atoms are observed. Two groups of tracks of 1.40 cm and 2.02 cm are noted. If the range-energy relation for cloud chamber is given by R = αE with α =1 cm/keV, obtain the binding energies of the two levels from which electrons are emitted. Given h = 6.63 × 10–34 J-s, e = 1.6 × 10–19 J.
  • 0.52 KeV
  • 0.75 eV
  • 0.52 eV
  • 0.75 keV
The wavelength of Kα, X-rays produced by an X-ray tube is 0.76 Å. The atomic number of the anode material of the tube is
  • 20
  • 60
  • 40
  • 80
X-ray beam of intensity I0passes through an absorption plate of thickness d. If absorption coefficient of material of plate is µ, the correct statement regarding the transmitted intensity I of X-rays is
  • I = I0(1 –e–µd)
  • I = I0e–µd
  • I = I0 (1 –eµ/d)
  • I = I0e–µ/d
The Kα, X-ray emission line of tungsten occurs at λ = 0.021 nm. The energy difference between K and L levels in this atom is about
  • 0.51 MeV
  • 1.2 MeV
  • 59 KeV
  • 13.6 eV
A silver ball of radius 4.8 cm is suspended by a thread in the vacuum chamber. UV light of wavelength 200 nm is incident on the ball for some time during which a total energy of 1 × 10–7 J falls on the surface. Assuming onan average one out of 103 photons incident is able to eject electron, the potential on sphere will be
  • 1 V
  • 2 V
  • 3 V
  • Zero

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  • 1
  • 1/4
  • 1/2
  • 2
A proton, a deutron and anα–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-68388.png
  • 1 : 2 : 8
  • 1 : 2 : 4
  • 1 : 1 : 2
  • None of these
0:0:1


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