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Physics M.C.Q (1 Marks)

Atoms · Rajasthan Board (RBSE) STD 12 Science (Rajasthan - English Medium). 21 questions.

Questions

M.C.Q (1 Marks)

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21 questions · auto-graded multiple-choice test.

MCQ 11 Mark
Which of the following statements is not correct according to Rutherford model ?
  • A
    Most of the space inside an atom is empty
  • B
    The electrons revolve around the nucleus under the influence of coulomb force acting on them
  • C
    Most part of the mass of the atom and its positive charge are concentrated at its centre
  • ✓
    The stability of atom was established by the model
Answer
Correct option: D.
The stability of atom was established by the model
D
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MCQ 31 Mark
The atomic number and mass number for a specimen are Z and A respectively. The number of neutrons in the atom will be :
  • A
    A
  • B
    Z
  • C
    $A+Z$
  • ✓
    $A-Z$
Answer
Correct option: D.
$A-Z$
D
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MCQ 41 Mark
In hydrogen atom the angular momentum of electron in ground energy state is :
  • A
    $h/\pi$
  • ✓
    $h/2\pi$
  • C
    $2\pi/h$
  • D
    $\pi/h$
Answer
Correct option: B.
$h/2\pi$
B
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MCQ 51 Mark
The energy of electron in first Bohr's orbit of hydrogen atom is $-13.6$ eV. What is energy of electron in its 2nd Bohr's orbit ?
  • ✓
    $-3.4$ eV
  • B
    $-6.8$ eV
  • C
    $-27.2$ eV
  • D
    $+3.4$ eV
Answer
Correct option: A.
$-3.4$ eV
A
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MCQ 61 Mark
Which series of hydrogen atom's spectrum does not lie in infrared region ?
  • A
    Humphreys series
  • B
    Pfund series
  • C
    Brackett series
  • ✓
    Lymann's series
Answer
Correct option: D.
Lymann's series
D
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MCQ 71 Mark
Wavelength of which series in hydrogen spectrum lies in visible region ?
  • A
    Lyman
  • B
    Paschen
  • ✓
    Balmer
  • D
    Brackett
Answer
Correct option: C.
Balmer
C
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MCQ 81 Mark
Specific charge of electron is :
  • ✓
    $1.8 \times 10^{11}$ C/kg
  • B
    $1.8 \times 10^{-19}$ C/kg
  • C
    $1.9 \times 10^{-19}$ C/kg
  • D
    None of these
Answer
Correct option: A.
$1.8 \times 10^{11}$ C/kg
A
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MCQ 91 Mark
In hard X-rays :
  • A
    value of wavelength is large
  • B
    intensity is large
  • C
    frequency is short
  • ✓
    energy of photon is more
Answer
Correct option: D.
energy of photon is more
D
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MCQ 101 Mark
The penetrating power of X-rays depends upon :
  • ✓
    the velocity of these rays
  • B
    current in the tube
  • C
    intensity of the rays
  • D
    nature of the cathode
Answer
Correct option: A.
the velocity of these rays
A
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MCQ 111 Mark
The velocity of X-rays having wavelength 1 Å will be :
  • ✓
    $3.0 \times 10^{8} m \, s^{-1}$
  • B
    $3.0 \times 10^{10} m \, s^{-1}$
  • C
    $3.0 \times 10^{11} m \, s^{-1}$
  • D
    $3.0 \times 10^{12} m \, s^{-1}$
Answer
Correct option: A.
$3.0 \times 10^{8} m \, s^{-1}$
A
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MCQ 121 Mark
If the potential difference applied to an X-ray tube is increased, then for the emitted radiation :
  • A
    the intensity will increase
  • B
    the minimum wavelength will increase
  • ✓
    the minimum wavelength will decrease
  • D
    the maximum frequency will decrease
Answer
Correct option: C.
the minimum wavelength will decrease
C
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MCQ 131 Mark
The minimum wavelength of X-rays emitted by coolidge tube depends upon :
  • A
    distance between cathode and target
  • ✓
    potential difference between cathode and target
  • C
    material of the cathode
  • D
    material of the target electrode
Answer
Correct option: B.
potential difference between cathode and target
B
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MCQ 141 Mark
The minimum wavelength of X-rays produced at accelerating potential V is $\lambda$. If the accelerating potential is changed to 4 V, the minimum wavelength would become :
  • A
    4$\lambda$
  • B
    2$\lambda$
  • ✓
    $\lambda/4$
  • D
    $\lambda/2$
Answer
Correct option: C.
$\lambda/4$
C
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MCQ 151 Mark
X-rays are :
  • A
    moving electrons
  • B
    moving positive ions
  • C
    moving negative ions
  • ✓
    electromagnetic waves
Answer
Correct option: D.
electromagnetic waves
D
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MCQ 161 Mark
The condition for stable orbit in Bohr's model of hydrogen atom is :
  • ✓
    quantization of angular momentum
  • B
    quantization of linear momentum
  • C
    quantization of energy
  • D
    none of these
Answer
Correct option: A.
quantization of angular momentum
A
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MCQ 171 Mark
In the given figures, three paths of an $\alpha$-particle passing nearby a nucleus (N) are shown. Among these, which path will be correct?
Image
  • A
    all the three paths
  • B
    only path-I
  • C
    only path-II
  • ✓
    only path-III
Answer
Correct option: D.
only path-III
D
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MCQ 181 Mark
In hydrogen atom the ratio $(1/137)$ of velocity of electron in first orbit to the velocity of light is called :
  • A
    Rydberg's constant
  • B
    Stefan's constant
  • ✓
    Fine structure constant
  • D
    Boltzman's constant
Answer
Correct option: C.
Fine structure constant
C
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MCQ 191 Mark
In which region of the electromagnetic spectrum does the Paschen series of hydrogen spectrum lie ?
  • ✓
    infrared region
  • B
    ultraviolet region
  • C
    visible region
  • D
    none of these
Answer
Correct option: A.
infrared region
A
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MCQ 201 Mark
Characteristic X-ray radiations are produced when :
  • A
    electrons are accelerated to a definite energy
  • B
    source of electrons should produce mono-chromatic electron beam
  • ✓
    the bombarding electrons should eject the electrons from the inner orbit and electrons from outer orbit should transit into the gap so formed
  • D
    the valency electrons should be removed due to collision of incident electrons
Answer
Correct option: C.
the bombarding electrons should eject the electrons from the inner orbit and electrons from outer orbit should transit into the gap so formed
C
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