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Dual Nature of Radiation and Matter

84 Questions
All Exams NEET AIIMS
2011 NEET MCQ
AIPMT 2011 Prelims
Photoelectric emission occurs only when the incident light has more than a certain minimum
A.
power
B.
wavelength
C.
intensity
D.
frequency
2011 NEET MCQ
AIPMT 2011 Prelims
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 NEET MCQ
AIPMT 2010 Mains
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 NEET MCQ
AIPMT 2010 Mains
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 NEET MCQ
AIPMT 2010 Prelims
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 NEET MCQ
AIPMT 2010 Prelims
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 NEET MCQ
AIPMT 2010 Prelims
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 NEET MCQ
AIPMT 2009
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 NEET MCQ
AIPMT 2009
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 NEET MCQ
AIPMT 2009
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 50 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 NEET MCQ
AIPMT 2008
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 NEET MCQ
AIPMT 2008
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 NEET MCQ
AIPMT 2008
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 NEET MCQ
AIPMT 2007
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 NEET MCQ
AIPMT 2007
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 NEET MCQ
AIPMT 2007
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 NEET MCQ
AIPMT 2006
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$-$24
D.
10$-$22
2006 NEET MCQ
AIPMT 2006
In a discharge tube ionization of enclosed gas is produced due to collisions between
A.
neutral gas atoms/molecules
B.
positive ions and neutral atoms/molecules
C.
negative electrons and neutral atoms/molecules
D.
photons and neutral atoms/molecules.
2006 NEET MCQ
AIPMT 2006
When photons of energy h$\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 NEET MCQ
AIPMT 2006
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 NEET MCQ
AIPMT 2005
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 NEET MCQ
AIPMT 2005
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 NEET MCQ
AIPMT 2004
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 36 English Option 1
B.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 36 English Option 2
C.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 36 English Option 3
D.
AIPMT 2004 Physics - Dual Nature of Radiation and Matter Question 36 English Option 4
2003 NEET MCQ
AIPMT 2003
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 NEET MCQ
AIPMT 2003
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 NEET MCQ
AIPMT 2002
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 NEET MCQ
AIPMT 2002
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 NEET MCQ
AIPMT 2002
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 NEET MCQ
AIPMT 2002
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 NEET MCQ
AIPMT 2001
Which one among the following shows particle nature of light?
A.
photo electric effect
B.
interference
C.
refraction
D.
polarization.
2001 NEET MCQ
AIPMT 2001
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 NEET MCQ
AIPMT 2001
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 NEET MCQ
AIPMT 2000
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 NEET MCQ
AIPMT 2000
Who evaluated the mass of electron infirectly with help of charge
A.
Thomson
B.
Millikan
C.
Rutherford
D.
Newton