+2 Physics Unit 6 - Atomic Physics
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Prepared by P. ILAIYARAJA M. Sc. ,B. Ed. , PG ASST IN PHYSICS , GHSS, PANCHANATHIKKULAM EAST, NAGAI DT. ; & www. Padasalai. Net
- 1.The cathode rays are
- A.
A stream of electrons
- B.
A stream of positive ions
- C.
A stream of uncharged particles
- D.
The same as canal rays
- 2.
![A narrow electron beam passes undeviated through an electric
field and an overlapping magnetic field
. The electron motion, electric field and magnetic
field are mutually perpendicular. The speed of the electron is
- ProProfs]( "A narrow electron beam passes undeviated through an electric
field and an overlapping magnetic field
. The electron motion, electric field and magnetic
field are mutually perpendicular. The speed of the electron is")
A narrow electron beam passes undeviated through an electric field and an overlapping magnetic field . The electron motion, electric field and magnetic field are mutually perpendicular. The speed of the electron is- A.
(3)
- B.
(1)
- C.
(2)
- D.
(4)
- 3.According to Bohr’s postulates, which of the following quantities take discrete values?
- A.
Angular momentum
- B.
Kinetic energy
- C.
Potential energy
- D.
Option 4
- 4.The ratio of the radii of the first three Bohr orbit is,
- A.
1 : 4 : 9
- B.
1 : 8 : 27
- C.
1 : 1/2 : 1/3
- D.
1 : 2 : 3
- 5.The first excitation potential energy or the minimum energy required to excite the atom from ground state of hydrogen atom is,
- A.
10.2 eV
- B.
13.6 eV
- C.
3.4 eV
- D.
1.89 eV
- 6.According to Rutherford atom model, the spectral lines emitted by an atom is,
- A.
Continuous spectrum
- B.
Continuous absorption specturm
- C.
line spectrum
- D.
Band spectrum
- 7.
![Energy levels A, B, C of a certain atom correspond to increasing
values of energy (i.e.,) . If are the wavelengths
of radiations corresponding to the transitions C to B, B to A and C
to A respectively, which of the following statements is correct.
- ProProfs]( "Energy levels A, B, C of a certain atom correspond to increasing
values of energy (i.e.,) . If are the wavelengths
of radiations corresponding to the transitions C to B, B to A and C
to A respectively, which of the following statements is correct.")
Energy levels A, B, C of a certain atom correspond to increasing values of energy (i.e.,) . If are the wavelengths of radiations corresponding to the transitions C to B, B to A and C to A respectively, which of the following statements is correct.- A.
(2)
- B.
(1)
- C.
(3)
- D.
(4)
- 8.The elliptical orbits of electron in the atom were proposed by
- A.
Sommerfeld
- B.
J.J.Thomson
- C.
Bohr
- D.
De Broglie
- 9.X−ray is
- A.
Phenomenon of conversion of kinetic energy into radiation.
- B.
Conversion of momentum
- C.
Conversion of energy into mass
- D.
Principle of conservation of charge
- 10.In an X-ray tube, the intensity of the emitted X−ray beam is increased by
- A.
Increasing the filament current
- B.
Decreasing the filament current
- C.
increasing the target potential
- D.
Decreasing the target potential
- 11.The energy of a photon of characteristic X-ray from a Coolidge tube comes from
- A.
An atomic transition in the target.
- B.
The kinetic energy of the striking electron
- C.
The kinetic energy of ions of the target
- D.
The kinetic energy of the free electrons of the target
- 12.
![A Coolidge tube operates at 24800 V. The maximum frequency of X radiation
emitted from Coolidge tube is
- ProProfs]( "A Coolidge tube operates at 24800 V. The maximum frequency of X radiation
emitted from Coolidge tube is")
A Coolidge tube operates at 24800 V. The maximum frequency of X radiation emitted from Coolidge tube is- A.
(1)
- B.
(2)
- C.
(3)
- D.
(4)
- 13.In hydrogen atom, which of the following transitions produce a spectral line of maximum wavelength
- A.
6 → 5
- B.
4 → 1
- C.
2 → 1
- D.
5 → 2
- 14.In hydrogen atom, which of the following transitions produce a spectral line of maximum frequency
- A.
2 → 1
- B.
6 → 2
- C.
4 → 3
- D.
5 → 2
- 15.After pumping process in laser,
- A.
The number of atoms in the excited state is greater than the number of atoms in the ground state.
- B.
The number of atoms in the ground state is equal to the number atoms in the excited state.
- C.
No atoms are available in the excited state.
- D.
The number of atoms in the ground state is greater than the number of atoms in the excited state.
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