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Dual Nature of Radiation and Matter

91 Questions Start NEET Test
All Exams NEET AIIMS
2012 Q51 NEET MCQ
10 Mar 2026
A 200 W sodium street lamp emits yellow light of wavelength 0.6 $\mu $m. Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is
A.
1.5 $ \times $ 1020
B.
6 $ \times $ 1018
C.
62 $ \times $ 1020
D.
3 $ \times $ 1019
2012 Q52 NEET MCQ
10 Mar 2026
An $\alpha $-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb/m2. The de Broglie wavelength associated with the particle will be
A.
1 $\mathop A\limits^ \circ $
B.
0.1 $\mathop A\limits^ \circ $
C.
10 $\mathop A\limits^ \circ $
D.
0.01 $\mathop A\limits^ \circ $
2012 Q53 NEET MCQ
10 Mar 2026
Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is
A.
4 $ \times $ 1015 Hz
B.
5 $ \times $ 1015 Hz
C.
1.6 $ \times $ 1015 Hz
D.
2.5 $ \times $ 1015 Hz
2011 Q54 NEET MCQ
10 Mar 2026
The threshold frequency for a photosensitive metal is 3.3 $ \times $ 1014 Hz. If light of frequency 8.2 $ \times $ 1014 Hz is incident on this metal, the cut- off voltage for the photoelectron emission is nearly
A.
1 V
B.
2 V
C.
3 V
D.
5 V
2011 Q55 NEET MCQ
10 Mar 2026
In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by
A.
increasing the potential difference between the anode and filament
B.
increasing the filament current
C.
decreasing the filament current
D.
decreasing the potential difference between the anode and flament
2011 Q56 NEET MCQ
10 Mar 2026
In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is
A.
1.8 V
B.
1.3 V
C.
0.5 V
D.
2.3 V
2011 Q57 NEET MCQ
10 Mar 2026
Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speeds of emitted electrons will be
A.
1 : 4
B.
1 : 2
C.
1 : 1
D.
1 : 5
2011 Q58 NEET MCQ
10 Mar 2026
Photoelectric emission occurs only when the incident light has more than a certain minimum
A.
power
B.
wavelength
C.
intensity
D.
frequency
2011 Q59 NEET MCQ
10 Mar 2026
Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de-Broglie wavelength associated with the electrons would
A.
increase by 2 times
B.
decrease by 2 times
C.
decrease by 4 times
D.
increase by 4 times
2010 Q60 NEET MCQ
10 Mar 2026
When monochromatic radiation of intensity $I$ falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2$I$, the number of emitted electrons and their maximum kinetic energy are respectively
A.
N and 2T
B.
2N and T
C.
2N and 2T
D.
N and T
2010 Q61 NEET MCQ
10 Mar 2026
The electron in the hydrogen atom jumps from excited state (n = 3) to its ground state (n = 1) and the photons thus emitted irradiate a photosensitive material. If the work function of the material is 5.1 eV, the stopping potential is estimated to be (the energy of the electron in nth state En = ${{ - 13.6} \over {{n^2}}}eV$)
A.
5.1 V
B.
12.1 V
C.
17.2 V
D.
7 V
2010 Q62 NEET MCQ
10 Mar 2026
The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work functions 5.01 eV, when ultraviolet light of 200 nm falls on it, must be
A.
2.4 V
B.
$-$ 1.2 V
C.
$-$ 2.4 V
D.
1.2 V
2010 Q63 NEET MCQ
10 Mar 2026
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 charge of the cathode rays is given by

(Where V is the potential difference between cathode and anode)
A.
${{{B^2}} \over {2V{E^2}}}$
B.
${{2V{B^2}} \over {{E^2}}}$
C.
${{2V{E^2}} \over {{B^2}}}$
D.
${{{E^2}} \over {2V{B^2}}}$
2010 Q64 NEET MCQ
10 Mar 2026
A source S1 is producing, 1015 photons per second of wavelength 5000 $\mathop A\limits^ \circ $. Another source S2 is producing 1.02 $ \times $ 1015 photons per second of wavelength 5100 $\mathop A\limits^ \circ $. Then, (power of S2)/(power of S1) is equal to
A.
1.00
B.
1.02
C.
1.04
D.
0.98
2009 Q65 NEET MCQ
10 Mar 2026
The number of photo electrons emitted for light of a frequency $\upsilon $ (higher than the threshold frequency ${\upsilon _0}$) is proportional to
A.
threshold frequency $\left( {{\upsilon _0}} \right)$
B.
intensity of light
C.
frequency of light $\left( {{\upsilon _0}} \right)$
D.
$\upsilon - {\upsilon _0}$
2009 Q66 NEET MCQ
10 Mar 2026
Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per sec. on the average at a target irradiated by this beam is
A.
3 $ \times $ 1016
B.
$9 \times {10^{15}}$
C.
$3 \times {10^{19}}$
D.
$9 \times {10^{17}}$
2009 Q67 NEET MCQ
10 Mar 2026
The figure shows a plot of photo current versus anode potential for a photo sensitive surface for three different radiations. Which one of the following is a correct statement?

AIPMT 2009 Physics - Dual Nature of Radiation and Matter Question 53 English
A.
Curves (a) and (b) represent incident radiations of same frequency but of different intensities.
B.
Curves (b) and (c) represent incident radiations of different frquencies and different intensities.
C.
Curves (b) and (C) represent incident radiations of same frequency having same intensity.
D.
Curves (a) and (b) represent incident radiations of different frequencies and different intensities
2008 Q68 NEET MCQ
10 Mar 2026
In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of
A.
collisions between the charged particles emitted from the cathode and the atoms of the gas
B.
collision between different electrons of the atoms of the gas
C.
excitation of electrons in the atoms
D.
collision between the atoms of the gas
2008 Q69 NEET MCQ
10 Mar 2026
A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of 3 $ \times $ 106 m s$-$1. The velocity of the particle is
A.
3 $ \times $ 10$-$31 ms$-$1
B.
$2.7 \times {10^{ - 21}}\,m{s^{ - 1}}$
C.
2.7 $ \times $ 10$-$18 ms$-$1
D.
9 $ \times $ 10$-$2 ms$-$1
2008 Q70 NEET MCQ
10 Mar 2026
The work function of a surface of a photosensitive material is 6.2 eV. The wavelength of the incident radiation for which the stopping potential is 5 V lies in the
A.
infrared region
B.
X-ray region
C.
Ultraviolet region
D.
Visible region
2007 Q71 NEET MCQ
10 Mar 2026
Monochromatic light of frequency 6.0 $ \times $ 1014 Hz is produced by a laser. The power emitted is 2 $ \times $ 10$-$3 W. The number of photons emitted, on the average, by the source per second is
A.
5 $ \times {10^{16}}$
B.
5 $ \times {10^{17}}$
C.
5 $ \times {10^{14}}$
D.
5 $ \times {10^{15}}$
2007 Q72 NEET MCQ
10 Mar 2026
A 5 watt source emits monochromatic light of wavelength 5000 $\mathop A\limits^ \circ $. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0 m, the number of photoelectrons liberated will be reduced by a factor of
A.
8
B.
16
C.
2
D.
4
2007 Q73 NEET MCQ
10 Mar 2026
A beam of electron passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same magnetic field is maintained, the electrons move
A.
in a circular orbit
B.
along a parabolic path
C.
along a straight line
D.
in an elliptical orbit.
2006 Q74 NEET MCQ
10 Mar 2026
The momentum of a photon of energy 1 MeV in kg m/s will be
A.
5 $ \times $ 10$-$22
B.
0.33 $ \times $ 106
C.
7 $ \times $ 10$-$24
D.
10$-$22
2006 Q75 NEET MCQ
10 Mar 2026
In a discharge tube ionization of enclosed gas is produced due to collisions between
A.
neutral gas atoms/molecules
B.
positive ions and neutral atoms/molecules
C.
negative electrons and neutral atoms/molecules
D.
photons and neutral atoms/molecules.
2006 Q76 NEET MCQ
10 Mar 2026
When photons of energy h$\upsilon $ fall on an aluminimum plate (of work function E0), photoelectrons of maximum kinetic energy K are ejected. If the frequency of radiation is doubled, the maximum kinetic energy of the ejected photoelectrons will be
A.
K + h$\upsilon $
B.
K + E0
C.
2K
D.
K.
2006 Q77 NEET MCQ
10 Mar 2026
A photocell employs photoelectric effect to convert
A.
change in the frequency of light into a change in the electric current
B.
change in the frequency of light into a change in electric voltage
C.
change in the intensity of illumination into a change in photoelectric current
D.
change in the intensity of illumination into a change in the work function of the photocathode.
2005 Q78 NEET MCQ
10 Mar 2026
A photosensitive metallic surface has work function, h$\upsilon $0. If photons of energy $2h{\upsilon _0}$ fall on this surface, the electrons come out with a maximum velocity of 4 $ \times $ 106 m/s. When the photon energy is increased to 5 h$\upsilon $0, then maximum velocity of photoelectrons will be
A.
2 $ \times $ 107 m/s
B.
2 $ \times $ 106 m/s
C.
8 $ \times $ 106 m/s
D.
8 $ \times $ 105 m/s
2005 Q79 NEET MCQ
10 Mar 2026
The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation the metals which will emit photoelectrons for a radiation of wavelength 4100 $\mathop A\limits^ \circ $ is/are
A.
A only
B.
A and B only
C.
all the three metals
D.
none
2004 Q80 NEET MCQ
10 Mar 2026
According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is
A.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 39 English Option 1
B.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 39 English Option 2
C.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 39 English Option 3
D.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 39 English Option 4
2003 Q81 NEET MCQ
10 Mar 2026
J.J. Thomson's cathode-ray tube experiment demonstrated that
A.
cathode rays are streams of negatively charged ions
B.
all the maas of an atom is essentially in the nucleus
C.
the e/m of electrons is much greater than the e/m of protons
D.
the e/m ratio of the cathode-ray particles changes when a different gas is placed in the discharge tube
2003 Q82 NEET MCQ
10 Mar 2026
A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then
A.
each emitted electron carries one quarter of the initial energy
B.
number of electrons emitted is half the initial number
C.
each emitted electron carries half the initial energy
D.
number of electrons emitted is a quarter of the initial number
2002 Q83 NEET MCQ
10 Mar 2026
The value of Planck's constant is
A.
6.63 $ \times $ 10$-$34 J/sec.
B.
6.63 $ \times $ 10$-$34 kg-m2/sec
C.
6.63 $ \times $ 10$-$34 kg-m2
D.
6.63 $ \times $ 10$-$34 J-sec.
2002 Q84 NEET MCQ
10 Mar 2026
When ultraviolet rays incident on metal plate then photoelectric effect does not occur, it occurs by incidence of
A.
infrared rays
B.
X-rays
C.
radio wave
D.
micro wave
2002 Q85 NEET MCQ
10 Mar 2026
Which of the following is not the property of cathode rays ?
A.
In produces heating effect
B.
It does not deflect in electric field
C.
It casts shadow
D.
It produces fluorscence.
2002 Q86 NEET MCQ
10 Mar 2026
If particles are moving with same velocity, then which has maximum de Broglie wavelength?
A.
proton
B.
$\alpha $-particle
C.
neutron
D.
$\beta $-particle
2001 Q87 NEET MCQ
10 Mar 2026
Which one among the following shows particle nature of light?
A.
photo electric effect
B.
interference
C.
refraction
D.
polarization.
2001 Q88 NEET MCQ
10 Mar 2026
A photo-cell is illuminated by a source of light, which is placed at a distance d from the cell. If the distance become d/2, then number of electrons emitted per second, will be
A.
remain same
B.
four times
C.
two times
D.
one-fourth
2001 Q89 NEET MCQ
10 Mar 2026
In Thomson mass spectrograph $\overrightarrow E \bot \overrightarrow B $ then the velocity of electron beam will be
A.
${{\left| {\overrightarrow E } \right|} \over {\left| {\overrightarrow B } \right|}}$
B.
$\overrightarrow E \times \overrightarrow B $
C.
${{\left| {\overrightarrow B } \right|} \over {\left| {\overrightarrow E } \right|}}$
D.
${{{{\overrightarrow E }^2}} \over {{{\overrightarrow B }^2}}}$
2000 Q90 NEET MCQ
10 Mar 2026
By photoelectric effect, Einstein proved
A.
E = h$\upsilon $
B.
K.E. = ${1 \over 2}$ mv2
C.
E = mc2
D.
E = ${{ - Rh{c^2}} \over {{n^2}}}$
2000 Q91 NEET MCQ
10 Mar 2026
Who evaluated the mass of electron infirectly with help of charge
A.
Thomson
B.
Millikan
C.
Rutherford
D.
Newton