JEE Questions for Physics Dual Nature Of Radiation And Matter Quiz 5 - MCQExams.com

A particle which has zero rest mass and non – zero energy and momentum must travel with a speed of
  • equal to c, the speed of light in vacuum.
  • Greater than c
  • Less than c
  • Tending to infinity
The work function of metal surface is 4.2 eV. The maximum wavelength which can eject electrons from this metal surface is
  • 3076Å
  • 4116Å
  • 2956Å
  • 5088Å
A photocell with a constant p.d of V volt across it is illuminate by a point source from a distance of 25 cm. When the source is moved to a distance of 1m, the electron emitted by the photocell.
  • carry 1⁄4 th their previous energy
  • are 1/16 th as numerous as before
  • are 1⁄4 th as numerous as before
  • are 1⁄4 th their previous momentum.
The correct curve between the stopping potential (Vs) and intensity of incident light (I) is

  • Physics-Dual Nature of Radiation and Matter-67421.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67422.png

  • Physics-Dual Nature of Radiation and Matter-67423.png

  • Physics-Dual Nature of Radiation and Matter-67424.png
In photoelectric effect, the photocurrent
  • depends both on intensity and frequency of the incident light
  • does not depend on the frequency of photon but depends only on intensity of incident light
  • decrease with increase frequency of incident photon
  • increase with increase of frequency of incident photon.
A metal surface of work function 1.07 eV is irradiated with light of wavelength 332 nm. The retarding potential required to stop the escape of photoelectrons is
  • 1.07 eV
  • 2.66 eV
  • 3.74 eV
  • 4.81 eV
The threshold frequency for photo electric effect on sodium corresponds to a wavelength of 5000Å. Its work function is

  • Physics-Dual Nature of Radiation and Matter-67426.png
  • 1J

  • Physics-Dual Nature of Radiation and Matter-67427.png

  • Physics-Dual Nature of Radiation and Matter-67428.png
Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material, photo electric current is emitted. If the frequency of light is halved and intensity is doubled, the photoelectric current becomes .
  • 4 times the original current
  • 2 times the original current
  • half the original current
  • zero times the original current
X – rays of frequency v are used to irradiate sodium and copper surface in two separate experiments and the stopping potential determined . Then
  • The stopping potential is more for sodium than for copper
  • The stopping potential is more for copper than for sodium
  • The stopping potential is same for sodium and copper
  • The stopping potential depends upon the area of the surface of cathode irridiated and position of anode in photoelectric cell.
If E and p are the energy and the momentum of a photon respectively then on increasing the wavelength of photon
  • p and E both will decrease
  • p and E both will increase
  • p will increase and E will decrease
  • p will decreases and E will increase
If the uncertainty in the position of an electron is 10-10 m, then the value of uncertainty in its momentum (in kg–ms-1) will be

  • Physics-Dual Nature of Radiation and Matter-67431.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67432.png

  • Physics-Dual Nature of Radiation and Matter-67433.png

  • Physics-Dual Nature of Radiation and Matter-67434.png
If the X – ray tube is working at 20 kv then the minimum wavelength of X – rays will be
  • 0.31Å
  • 0.62Å
  • 0.93Å
  • 0.47Å
An X – ray tube is operated at an accelerating potential of 40 kV and the current in the tube is 20 mA. Only 2% of the total energy given is converted into X – rays. The maximum energy of emitted radiations will be

  • Physics-Dual Nature of Radiation and Matter-67437.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67438.png

  • Physics-Dual Nature of Radiation and Matter-67439.png

  • Physics-Dual Nature of Radiation and Matter-67440.png
In photoelectric effect, the work function of a metal is 3.5 eV. The emitted electrons can be stopped by applying a potential of –1.2 V. Then
  • the energy of the incident photon is 4.7 eV
  • The energy of the incident photon is 2.3 eV
  • If higher frequency photons be used, the photoelectric current will rise
  • When the energy of photons is 3.5 eV, the photoelectric current will be maximum.
When a centimeter thick surface is illuminated with light of wavelength λ stopping potential is V. When the same surface is illuminated by light of wavelength 2 λ stopping potential is V/3. Threshold wavelength for metallic surface is
  • 4λ/3
  • 4λ
  • 6λ
  • 8λ/3
Which of the following statements is correct ?
  • the current in a photocell increases with increasing frequency of light
  • the photo current is proportional to applied voltage
  • the photo current increases with the increasing intensity of light
  • the stopping potential increases with increasing intensity of light
The kinetic energy of an electron which is accelerated through a potential of 100 volts is

  • Physics-Dual Nature of Radiation and Matter-67444.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67445.png

  • Physics-Dual Nature of Radiation and Matter-67446.png

  • Physics-Dual Nature of Radiation and Matter-67447.png
The photoelectric work function for a metal surface is 4.125 eV. The cut off wavelength for this surface is
  • 4125Å
  • 2062.5Å
  • 3000Å
  • 6000Å
Einsteins’s work on the photoelectric effect provided support for the equation
  • E= mc2
  • 2)
    Physics-Dual Nature of Radiation and Matter-67450.png

  • Physics-Dual Nature of Radiation and Matter-67451.png

  • Physics-Dual Nature of Radiation and Matter-67452.png
A particle with a specific charges S is fired with a speed v towards a wall at a distance d, perpendicular to the wall. What minimum must exist in this region for particle not to hit the wall?

  • Physics-Dual Nature of Radiation and Matter-67453.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67454.png

  • Physics-Dual Nature of Radiation and Matter-67455.png

  • Physics-Dual Nature of Radiation and Matter-67456.png
Particle nature and wave nature of electro-magnetic waves and electrons be shown by
  • electrons have small mass, deflected by the metal sheet
  • X – ray is diffracted, reflected by thick metal sheet
  • Light is refracted and diffracted
  • Photoelectricity and electron microscopy.
The wavelength associated with a gold ball weighing 200 g and moving at a speed of 5 m/h is of the order of (h=(6.626 × 10−34 JS))
  • 10-10 m
  • 10-20m
  • 10-30 m
  • 10-40m
Gases begin to conduct electricity at low pressure because
  • at low pressure, gases turn into plasma
  • colloiding electrons can acquire higher K.E. due to increased mean free path leading to ionization of atoms
  • atom break up into electrons and protons
  • the electrons in atoms can move freely at low pressure.
Which is not true with respect to the cathode rays?
  • A stream of electrons
  • Charged particles
  • Move with speed same as that of light
  • Can be deflected by magnetic fields
  • Can be deflected by electric fields
When ultraviolet rays incident on metal plate then photoelectric effect does not occur, it occurs by incidence of
  • infrared rays
  • radiowaves
  • X – rays
  • Light waves
The potential difference applied to an X – ray tube is 5kV and the current through it is 3.2 mA. Then the number of electrons striking the target per second is

  • Physics-Dual Nature of Radiation and Matter-67459.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67460.png

  • Physics-Dual Nature of Radiation and Matter-67461.png

  • Physics-Dual Nature of Radiation and Matter-67462.png
In Thomson’s experiment of finding e/m for electrons, beam of electron is replaced by that of muons (particle with same charge as that of electrons but of mass 208 times that of electron). No deflection condition in this case is satisfied if.
  • B is increased 208 times
  • E is increased 208 times
  • B is increased 14.4 times
  • None of these
The speed of an electron having a wavelength of 10-10 m is

  • Physics-Dual Nature of Radiation and Matter-67465.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67466.png

  • Physics-Dual Nature of Radiation and Matter-67467.png

  • Physics-Dual Nature of Radiation and Matter-67468.png
An X–ray photon has a wavelength 0.01Å. Its momentum (in kg ms-1) is (Given h = 6.6 × 10-34 Js)

  • Physics-Dual Nature of Radiation and Matter-67470.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67471.png

  • Physics-Dual Nature of Radiation and Matter-67472.png
  • 0
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
  • 540 nm
  • 400 nm
  • 310 nm
  • 220 nm
A charged oil drop is suspended in a uniform electric field of 3 × 104 V/m so that it neither falls nor rises . The charge on the drop will be (take the mass of the drop is 9.9 × 10-15 kg and g = 10 ms-2)

  • Physics-Dual Nature of Radiation and Matter-67475.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67476.png

  • Physics-Dual Nature of Radiation and Matter-67477.png

  • Physics-Dual Nature of Radiation and Matter-67478.png
Which of the following have highest specific charge?
  • Positron
  • Proton
  • α − particle
  • none of these
Particle A and B have electric charge + q and + 4 q. Both have mass m. If both are allowed to fall under the same p.d., ratio of velocities vA/vB =
  • 2 : 1
  • 1 : 2
  • 1 : 4
  • 4 : 1
Energy of photon having wavelength λ is 2 eV. This photon when incident on metal. maximum velocity of emitted is v. If λ is decreased 25% and maximumu velocity is made double, work function of metal is ........ev
  • 1.2
  • 1.5
  • 1.6
  • 1.8
If velocity of free election is made double, change in its de-Broglie wavelength will be......

  • Physics-Dual Nature of Radiation and Matter-67482.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67483.png

  • Physics-Dual Nature of Radiation and Matter-67484.png

  • Physics-Dual Nature of Radiation and Matter-67485.png
de-Broglie wavelength of proton accelerated under 100 V electric potential difference is λ0 . If de - wave length α - particle accelerated by the same electric potential difference will its bouglie ............

  • Physics-Dual Nature of Radiation and Matter-67487.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67488.png

  • Physics-Dual Nature of Radiation and Matter-67489.png

  • Physics-Dual Nature of Radiation and Matter-67490.png
Work function of a body is 4.0 eV. For emission of photo electron from body, maximum wavelength of light = ..........
  • 540 nm
  • 400 nm
  • 310 nm
  • 220 nm
A body of mass 200 g moves at the speed of 5 m/hr. So de-Broglie wavelength related to it is of the order........ (h = 6.626 × 10–34 J - s)
  • 10–10 m
  • 10–20 m
  • 10–30 m
  • 10–40 m
Photo electric effect on surface is found for frequencies 5.5 × 108 MHz and 4.5 × 108 MHz If ratio of maximum kinetic energies of emitted photo electrons is 1 : 5, threshold frequency for metal surface is................
  • 7.55 × 108 MHz
  • 4.57 × 108 MHz
  • 9.35 × 108 MHz
  • 5.75 × 108 MHz
For wave concerned with proton, de - Broglie wavelength change by 0.25% . If its momentum changes by PO initial momentum = ........
  • 100 Po
  • 2)
    Physics-Dual Nature of Radiation and Matter-67495.png
  • 401 Po

  • Physics-Dual Nature of Radiation and Matter-67496.png
According to Einstein\'s photoelectric equation, graph of kinetic energy of emitted photo electrons from metal versus frequency of incident radiation is linear. Its shope.............
  • depends on type of metal used
  • depends on intensity of radiation
  • depends on both metal used and intensity of radiation.
  • is same for all metals and free from intensity of radiation.
Energy corresponding to threshold frequency of metal is 6.2 eV. If stopping potential corresponding to radiation incident on surface is 5V, incident radiation will be in the.....region.
  • X-ray
  • Ultraviolet
  • infrared
  • Visible
At 10oC temperature, de-Broglie wave length of atom is 0.4Å . If temperature of atom is increased by 30oC , what will be change in de-Broglie wavelength of atom ?
  • decreases 10–2 Å
  • decreases 2 × 10–2 Å
  • increases 10–2 Å
  • increases 2 × 10–2 Å
Wavelength of incident radiation on photo sensitive surface is changed from 4000 Å to 3000 Å , so change in stopping potential will be.......
  • 0.345 V
  • 0.435 V
  • 0.543 V
  • 0.534 V
Wavelength of incident radiation on photo sensitive surface is 4000 Å If wavelength of this light is 3600 Å , what will be change in kinetic energy of emitted photo electron ? (h = 6.625 × 10–34 J.s, c = 3 × 108 ms–1, 1eV = 1.6 × 10–19 J)
  • 0.52 eV
  • 1.04 eV
  • 2.08 eV
  • 4.16 eV
A hollow metallic custodial has mass 10 kg and length 10 cm. At what speed this custodial is moved in X-direction so that its de-Broglie wavelength exactly trapped in the custodial ?

  • Physics-Dual Nature of Radiation and Matter-67501.png
  • 2)
    Physics-Dual Nature of Radiation and Matter-67502.png

  • Physics-Dual Nature of Radiation and Matter-67503.png

  • Physics-Dual Nature of Radiation and Matter-67504.png
If we take accelerating voltage V = 50 V, electric charge of electron e = 1.6 × 10–19 C and mass of electron m = 9.1 × 10–31 kg find the wavelength of concerned electron.
  • 0.1735 Å
  • 1.735 Å
  • 17.35 Å
  • 1735 Å
What will be energy in eV of photons of λ- rays having length 0.1 Å coming out of excited nucleus of radium?
Physics-Dual Nature of Radiation and Matter-67507.png
  • 42.12
  • 12.42
  • 22.41
  • 24.21
How many photons of red coloured light having wavelength 8000 Å will have same energy as one photon of violet coloured light of wavelength 4000 Å ?
  • 2
  • 4
  • 6
  • 8
When a radiation of wavelength 3000 Å is incident on metal, 1.85 V stopping potential is obtained . What will be threshold wave length of metal ?
Physics-Dual Nature of Radiation and Matter-67510.png
  • 4539 Å
  • 3954 Å
  • 5439 Å
  • 4395 Å
0:0:1


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