Atomic Spectra Class 12 MCQ: Class 12 Physics MCQ Questions and Answer. Students get here all Important MCQ on Atomic Spectra Class 12.
Atomic Spectra Class 12 MCQ with Answers:
Multiple choice questions.
1.) The relation between wavelength λ and Rydberg’s constant RH in Balmer series is,
a) 1/λ = RH((1/2²)-(1/n²))
b) 1/λ = RH((1/5²)-(1/n²))
c) 1/λ = RH((1/3²)-(1/n²))
d) 1/λ = RH((1/4²)-(1/n²))
Ans : a) 1/λ = RH((1/2²)-(1/n²))
2.) The relation between wavelength λ and Rydberg’s constant RH in Lyman series is,
a) 1/λ = RH((1/2²)-(1/n²))
b) 1/λ = RH((1/5²)-(1/n²))
c) 1/λ = RH((1/1²)-(1/n²))
d) 1/λ = RH((1/4²)-(1/n²))
Ans : c) 1/λ = RH((1/1²)-(1/n²))
3.) The relation between wavelength λ and Rydberg’s constant RH in Paschen series is,
a) 1/λ = RH((1/2²)-(1/n²))
b) 1/λ = RH((1/5²)-(1/n²))
c) 1/λ = RH((1/1²)-(1/n²))
d) 1/λ = RH((1/3²)-(1/n²))
Ans : d) 1/λ = RH((1/3²)-(1/n²))
4.) The relation between wavelength λ and Rydberg’s constant RH in Brackett series is,
a) 1/λ = RH((1/2²)-(1/n²))
b) 1/λ = RH((1/4²)-(1/n²))
c) 1/λ = RH((1/1²)-(1/n²))
d) 1/λ = RH((1/3²)-(1/n²))
Ans : b) 1/λ = RH((1/4²)-(1/n²))
5.) The relation between wavelength λ and Rydberg’s constant RH in Brackett series is,
a) 1/λ = RH((1/2²)-(1/n²))
b) 1/λ = RH((1/4²)-(1/n²))
c) 1/λ = RH((1/5²)-(1/n²))
d) 1/λ = RH((1/3²)-(1/n²))
Ans : c) 1/λ = RH((1/5²)-(1/n²))
6.) n be the principal quantum number, m and v are the mass and velocity of the orbiting electrons and h be the Planck’s constant then the relation between them is,
a)mnh = vr/2π. b) mvh = nr/2π
c) mvr = nh/2π. d) nh = mvr/2π
Ans : c) mvr = nh/2π
7.) Complete the postulate.
” Only those stationary orbits are allowed for which orbital angular momentum is equal to an integral multiple of ______”
a)1/2π. b) h/2π
c) π/2h. d) 2π/h
Ans : b) h/2π
8.) The energy required to completely remove an electron from the first Bohr orbit. This energy is called,
a) Electron energy. b) Hydro energy
c) Binding energy. d) Ionisation energy
Ans : d) Ionisation energy
9.) The value of E = 2π²k²me⁴/h² = constant is
a)12.3 eV. b) 1.87 eV
c) 13.6 eV. d) 19.3 eV
Ans : c) 13.6 eV
10.) The speed of electron is the nth orbit is
vn = 2πke²/______
a) nh. b)3n²h
c) n²h. d) nrh
Ans : a) nh
11.) The value of Rydberg’s constant is,
a) 1.0974×10-8m-2
b) 1.0974×107m-1
c) 10.974×10-7m-2
d) 1.0974×10-8m-2
Ans : b) 1.0974×107m-1
12) The radius of hydrogen atom is about,
a) 5×10¹¹ m-1.
b) 5×10–¹⁰ N
c) 5×10-11m
d) 4×10¹¹m
Ans : c) 5×10-11m
13.) It is the acronym for light Amplification by Stimulated Emission of Radiation, what is if called.
a)CAT-scanner.
b) Laser
c) X-ray tube.
d) X- ray spectrum
Ans : b) Laser
14.) How many percent of Helium filled in the discharge tube of Helium – Neon laser.
a)80%.
b) 95%
c) 75%.
d) 85%
Ans : d) 85%
15.) How many percent of Neon filled in the discharge tube of Helium-Neon laser.
a)20%.
b) 5%
c) 15%.
d) 25%
Ans : c) 15%
16.) Whenever an electron makes a transition, i.e., jumps from high energy state E to a lower energy state E,a photon of energy h is emitted so that.
a)f = h(Ep-En).
b) hf = En-Ep
c) f = h(En-Ep)
d) fh = Ep-En
Ans : b) hf = En-Ep
17.) The X- ray emitted in inner shell transition are called,
a) X-ray spectrum
b) Characteristic X- ray
c) X- ray tube
d) Continuous X-rays
Ans : b) Characteristic X-ray
18.) In characteristic X-ray their energy depend upon the type of _______
a) Large material
b) Smaller material
c) Target material
d) Direction material
Ans : c) Target material
19.) The incident photon absorbed by an atom in the ground state E, there by leaving the atom in the excited state E is called,
a) Addition absorption
b) Magnetic fussion
c) Photo emission
d) Induced absorption
Ans : d) Induced absorption
20.) The X-rays that are emitted in all directions and with a continuous range of frequencies are known as.
a) X- ray spectra
b) Characteristic X-ray
c) Continuous X-rays
d) X-ray tube
Ans : c) Continuous X-rays
21.) The spontaneous emission is that in which the atom emits a photon of energy in any arbitrary direction, can be expressed as,
a) hf= (E2-E1).
b) f = h( E2-E1)
c) f = h(E1/E2)
d) fh = E2/E1
Ans : b) hf = E2-E1
22.) If V be the potential difference between C and T of the X-ray tube then Kinetic energy can be expressed as,
a) K.E = Ve
b) K.E = V/2e
c) K.E = 2Ve
d) K.E = 1/Ve
Ans : a) K.E = Ve
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