Q.1
The wavelenght λ of the Kα X-ray line of an anticathode element of atomic number z is nearly proportional to ...[ MPPMT 1987]
  • a)Z2
  • b) (Z - 1)2
  • c)1/Z-1
  • d)1 / (Z-1)2
Q.2
Both γ-rays and X-rays are electromagnetic waves. the basic difference in them is [ raj.PMT 1997]
  • a) The production of X-rays is a nuclear property whereas the production of γ-rays is an atomic property
  • b) The production of X-rays is an atomic property whereas the production of γ-rays is a nuclear property
  • c)γ rays have less frequency than X-rays
  • d)the velocity of γ rays is more than that of X-rays
Q.3
X-rays passing through a strong uniform magnetic field [ CPMT 1998]
  • a) get deflected in the direction of the field
  • b) get deflected in the direction opposite to that of field
  • c)get deflected in the direction perpendicular to that of the field
  • d)do not get deflected at all
Q.4
The X-ray beam coming from an X-ray tube will be [ IIT 1985]
  • a) Monochromatic
  • b) Haing all wavelengths smaller than a certain maximum wavelength
  • c) Having all wavelengths larger than a certain minimum wavelength
  • d) HAving all wavelengths lying between a minimum and maximum wavelength
Q.5
What happens when fast moving electrons are stopped and fall on the metallic target in an evacuated glass bulb [ MPPMT 1997]
  • a)β particles are produced
  • b) Metal become soft
  • c)γ rays are produced
  • d)X-rays are produced
Q.6
X ray is ...[ CPMT 1999]
  • a) Phenomenon of conservation of Kinetic energy into radiation energy
  • b) Conservation of momentum
  • c)Conservation of mass into energy
  • d)principal of conservation of charge
Q.7
Bragg's equation will not have solution if ....
  • a) λ > 2d
  • b)λ < 2d
  • c)λ < d
  • d)λd
Q.8
Kα characteristic X-ray refers to the transition ..[ MPPMT 1999]
  • a) n=2 to n=1
  • b) n=3 to n=2
  • c) n=3 to n=1
  • d) n=4 to n=2
Q.9
The potential difference applied to an X-ray tube is increased. As a result, in the emitted radiation [ ISM Dhanbad]
  • a)the intensity increases
  • b) the minimum wavelength increases
  • c)the maximum wavelength increases
  • d)the minimum wavelength decreases but intensity remains same
Q.10
When a beam of accelerated electrons hits a target which of the following wavelengths is absent in the X-ray region of spectrum, if the X-ray tube is operating at 40000 volt [ MNR 1995]
  • a) 1.5 Å
  • b) 0.5 Å
  • c)0.25 Å
  • d)1.0 Å
Q.11
The ratio of the energy of an X-ray photon of wavelength 1 Å to that of visible light of wavelength 5000 Å is [ EAMCET 1995]
  • a) 1 : 5000
  • b) 5000 : 1
  • c) 1 : 25 ×106
  • d) 25 × 106
Q.12
The frequency of Kα line for an element of Z=64 is Vα and that for an element Z=80 is v'α. The ratio of frequencies of Kα lines of these elements is
  • a) √(2/5)
  • b) 2/√5
  • c)16/25
  • d)2/5
Q.13
The wavelength of Kα lines given by molybdenum ( atomic number=42) is 0.7078Å then wavelength of Kα for zinc ( atomic number 30) will b [ raj. PET 1997]
  • a) 0.354 Å
  • b) 1.4147 Å
  • c)09425 Å
  • d)1.2547 Å
Q.14
Velocity of photon is proportional to [ CBSE 1996] ν is frequency
  • a) ν
  • b) ν1/2
  • c)ν-1/2
  • d) ν0
Q.15
For photoelectric emission from certain metal the cut-off frequency is ν. If radiation of frequency 2ν impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass)…[NEET 2013]
  • a)
    ch-9_qn-313choice_img_no1.png
  • b)
    ch-9_qn-313choice_img_no2.png
  • c)
    ch-9_qn-313choice_img_no3.png
  • d)
    ch-9_qn-313choice_img_no4.png
Q.16
The wavelength λe of an electron and λp of aphoton of same energy E are related by
  • a)
    ch-9_qn-314choice_img_no1.png
  • b)
    ch-9_qn-314choice_img_no2.png
  • c)
    ch-9_qn-314choice_img_no3.png
  • d)
    ch-9_qn-314choice_img_no4.png
Q.17
The wavelength associated with a gold ball weighing 200g and moving at speed of 5m/h is of the order of ( h=6.625 × 10⁻³⁴ Js) [ IIT 2001]
  • a) 10-10 m
  • b) 10-20 m
  • c) 10-30 m
  • d) 10-40 m
Q.18
The momentum of pfoton of an electromagnetic radiation is 3.3×10⁻²⁹ kgms-What is the frequaency of the associated waves? [ CBSE-PMT 1990] h=6.6×10⁻³⁴Js; c=3×108 ms-1
  • a)1.5 × 1013 Hz
  • b) 7.5 × 1012 Hz
  • c)6.0×103
  • d)3.0×103
Q.19
Monochromatic light of frequaency 6.0×1014 Hz is produced by a laser. the power emitted is 2×10⁻³ W. The number of photons emitted, on the average, by the sources per second is ... [ CBSE-PMT 2007]
  • a) 5×1016
  • b) 5×1017
  • c) 5×1014
  • d) 5×1015
Q.20
A particle of mass 1mg has the same wave length as an electron moving with velocity of 3×106 ms-The velocity of the particle is [ CBSE-PMT 2008] mass of electron=9.1×10⁻³¹ kg
  • a)2.7×10⁻¹⁸ m/s
  • b) 9×10⁻² m/s
  • c)3×10⁻³¹m/s
  • d)2.7×10⁻²¹m/s
Q.21
Given that a photon of light of wavelength 10,000Å has an energy equal to 1.23 eV, when light of wave length 5000Å and intensity I0 falls on photoelectric cell and the saturation current is 0.40×10⁻⁶ ampere stopping potential is 1.36 V. Then the work function is .. [ CPMT 1977]
  • a) 0.43 eV
  • b) 1.10eV
  • c)1.36eV
  • d)2.47eV
Q.22
Given Plank's constant h=6.6×10⁻³⁴ J-sec. The momentum of each photon in a given radiation is 3.3 ×10⁻²⁹ kg-m/sec. The wave-length of radiation is
  • a) 3 × 10⁻³ m
  • b) 6 × 10⁻¹⁰ m
  • c)7.5 × 10⁻² m
  • d)2 × 10⁻⁵ m
Q.23
The de-Broglie wavelength associated with moving electrons is 0.24×10⁻¹⁰ m. The voltage applied between grids to bring it to rest is
  • a) 1000 volts
  • b) 2597 volts
  • c)2597 volts
  • d)none of above
Q.24
When light of intensity 1 W/m2 and wavelength 5×10⁻⁷ is incident on a surface. It is completely absorbed by the surface. If 100 photons emit one electron and area of surface is 1cm2, then the photoelectric current will be
  • a) 2mA
  • b) 0.4 µA
  • c) 4.0 mA
  • d) 4 µA
Q.25
If 5% of the energy supplied to a bulb is radiated as visible light, how many quanta are emitted per second by a 100 watt lamp? Assume wavelength of visible light as 5.6×10⁻⁵ cm
  • a) 1.4 × 1019
  • b) 2.0 × 10⁻⁴
  • c) 1.4 × 10⁻¹⁹
  • d) 2.0 × 104
Q.26
When α-particles are accelerated under the p.d of V volt, their de-Broglie's wavelength is ...Å [ Mass of alpha particle=6.4 ×10⁻²⁷ kg and its charge is 3.2×10⁻¹⁹ C.
  • a)0.287/√V
  • b) 12.27/√V
  • c)0.103/√V
  • d)1.22/√V
Q.27
To reduce de_broglie wavelength of an electron from 10-10m to 0.5×10⁻¹⁰m, its energy should be ...
  • a) increased to four times
  • b) doubled
  • c)halved
  • d)decreased
Q.28
The work function of a metallic substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from the substance is approximately.. [ AFMC 1998]
  • a)220 nm
  • b) 310 nm
  • c)400 nm
  • d)540 nm
Q.29
The wave length of a particle having a momentum of 2×10⁻²⁸ kgm/s is ..[ AFMC 2002]
  • b) 3.3×105 m
  • d) 30 m
  • a) 3.3×10⁻⁶m
  • c) 3.3×10⁻⁴m
Q.30
What is the de-Broglie wavelength of 1 kg mass moving with a velocity of 10 m/s? [ AFMC 2001]
  • d) none of these
  • a) 6.626×10⁻³⁵ m
  • b) 6.626×10⁻³³ m
  • c) 6.626×10⁻³⁴ m
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