Q.1
If E1, E2 and E3 are the respective kinetic energies of an electron, an alpha particle and a proton each having the same de Brogli wavelength then
  • a)E1 > E3 > E2
  • b) E2 > E3 > E1
  • c)E1 > E2 > E2
  • d)E1=E2=E3
Q.2
A particle of mass 10-31 kg is moving with velocity equal to 105 m/sec. The wavelength of the particle is equal to
  • a) 0
  • b) 6.6 ×10-8 m
  • c)0.66 m
  • d)1.5 × 107
Q.3
An electron has a speed of 100 m/s with an accuracy of 0.005%. The uncertainty in position will be
  • a) 0.14 m
  • b) 1.4 m
  • c)0.014 m
  • d)14.0 m
Q.4
A proton when accelerated through a potential difference of V volts has a wavelength λ associated with it. An α-particle in order to have the same λ must be accelerated through a potential difference of
  • a) V volt
  • b) 4V volt
  • c) 2V volt
  • d) V/8 volt
Q.5
The momentum of photon ( in kgms-1) of frequency 109 cycles per second is
  • a)7.3 ×10-29
  • b) 2.2 × 10-33
  • c)6.6 ×10-26
  • d)3.1
Q.6
An electron accelerated through a potential difference of V volts has wavelength λ associated with it. Mass of proton is nearly 2000 times that of electron. In order to have the same λ for proton, it must accelerate through a potential difference o
  • a) V volts
  • b) 2000 V volt
  • c)V/20000 volt
  • d)√(2000) v volt
Q.7
A tiny particle of mass 10-13 kg moving with a velocity of 10 cm/sec is associated with the wavelength
  • a) 6.62 × 10-20 m
  • b)6.62 × 10-20 cm
  • c)6.62 × 10-34 cm
  • d)6.62 × 10-13 m
Q.8
The momentum of electrons having a wavelength of 100 A.U. is
  • a) 6.6 ×10-32 gm ×cm / sec
  • b) 6.6 ×10-29 gm ×cm / sec
  • c) 6.6 ×10-25 gm ×cm / sec
  • d) 6.6 ×10-21 gm ×cm / sec
Q.9
In Bohr's atom the number of de Broglie waves associated with an electron moving in nth permitted orbit is
  • a)n
  • b) 2n
  • c)n/2
  • d)n2
Q.10
A moving particle is associated with a wave packet or group of waves. The group velocity is equal to
  • a) velocity of light
  • b) velocity of sound
  • c)velocity of particle
  • d)1/ particle velocity
Q.11
According to wave mechanics, a material particle is associated with
  • a) a single wave
  • b) a wave packet
  • c)two progressive waves
  • d)a ripple
Q.12
The de Broglie wavelength of an electron in 1.224 Å. The energy of electron is eV is
  • a) 1 eV
  • b) 10eV
  • c) 100eV
  • d) 1224eV
Q.13
The de Broglie wave length associated with an electron moving with (1/10)th of the velocity of light is
  • a)0.24 ×10-19 m
  • b) 0.24 ×10-10 m
  • c)1.24 ×10-10 m
  • d)0.48 ×10-10 m
Q.14
The uncertainty principle is applicable to
  • a) Large system only
  • b) small system only
  • c)sub atomic particles only
  • d)both sub-atomic and large particle
Q.15
The de-Broglie wavelength of a molecule of thermal energy KT ( K is Boltzmann constant and T is absolute temperature) is
  • a)
    ch-9_qn-123choice_img_no1.png
  • b)
    ch-9_qn-123choice_img_no2.png
  • c)
    ch-9_qn-123choice_img_no3.png
  • d)
    ch-9_qn-123choice_img_no4.png
Q.16
The de-Broglie wavelength associated with thermal neutron ( t=51°C say) is of the order of the
  • a) Distance between the atoms in the crystal
  • b) size of the nucleus
  • c) Bohr's radius
  • d) size of grain
Q.17
An electron, proton and a car all have same wavelength. The one possessing highest velocity is
  • a)electron
  • b) proton
  • c)car
  • d)all have same velocity
Q.18
The de Broglie wavelength of 150 eV electron will be
  • a) 1 Å
  • b) 12.27 Å
  • c)0.5 Å
  • d)1.5 Å
Q.19
In the hydrogen atom an electron is moving in nth orbit. The circumference s of the orbit and the de Broglie wavelength, λ of the moving electron are related by the equation
  • a) s=nλ
  • b) s=n/λ
  • c)s=λ/n
  • d)s=1/ nλ
Q.20
The uncertainty in the location of a particle is equal to its de Broglie wavelength then the uncertainty in its velocity will be
  • a) Its velocity
  • b) Half of its velocity
  • c) Twice its velocity
  • d) Four times its velocity
Q.21
What is the de Broglie wave length of an electron accelerated through 40kV?
  • a)614 pm
  • b) 61.4 pm
  • c)6.14 pm
  • d)0.614 pm
Q.22
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.23
Matter waves are similar in nature to
  • a) X-rays
  • b) γ-rays
  • c)Cathode rays
  • d)none of the above
Q.24
The propagation constant of the de Broglie waves associated with an electron is
  • a) Proportional to its mass
  • b) Proportional to its momentum
  • c) Proportional to its energy
  • d) Inversely proportional to its energy
Q.25
The wavelength of the matter wave is independent of
  • a)mass
  • b) velocity
  • c)momentum
  • d)charge
Q.26
An electron accelerated by a potential difference of V volt posses a de Broglie wave length λ. If the accelerating potential is increased by a factor of 4, the de-Broglie wavelength of the electron will be
  • a) Remains unchaged
  • b) Becomes 4 times
  • c)Becomes Half
  • d)Becomes double
Q.27
A photon and electron have same wave length then
  • a) photon has greater momentum
  • b) electron has greater momentum
  • c)they have the same momentum
  • d)none of the above
Q.28
The function of the crystal in Davisson and Germer experiment is
  • a) To reflect the electron beam
  • b) To refract the electron beam
  • c) To diffract the electron beam
  • d) To focus the electron beam
Q.29
The interplanar spacing of crystal is 1.225 Å. the maximum order of diffraction of electrons accelerated through a potential difference of 10 kV is
  • a) 1
  • b) 20
  • c)100
  • d)1000
Q.30
A particle of mass 1kg is moving with a velocity of 1m/s. The de-broglie wavelength associated with it will be
  • a) h
  • b) h/2
  • c) h/4
  • d) 2h
0 h : 0 m : 1 s