Quiz: Chapter 15 - Atomic Spectra

1 The Einstein mass-energy relationship is

E = mc E = mc³ E = mc² E = m²c²

2 A positron is a particle having

Mass equal to electron Charge equal to electron Equal mass but opposite charge to electron Mass equal to proton

3 When an electron combines with a positron, we get

One photon Two photons Three photons Four photons

4 In Compton scattering, the Compton shift Δλ will be equal to Compton wavelength if the scattering angle is

0° 45° 60° 90°

5 Production of X-rays can be regarded as the reverse phenomenon of

Pair production Photoelectric effect Compton effect Annihilation of matter

6 The radius of an atom is of the order of

10¹⁰ m 10⁻¹⁰ m 10⁻¹⁴ m 10¹⁴ m

7 In 1905, the special theory of relativity was proposed by

Maxwell De Broglie Bohr Einstein

8 The neutron was discovered in 1932 by

Bohr Chadwick Dirac Fermi

9 The rest mass of a photon is

Infinity Zero hf mc²

10 A maximum Compton shift in the wavelength of a scattered photon will occur at

θ = 0° θ = 45° θ = 90° θ = 180°

11 The Davisson and Germer experiment indicates

Interference Polarization Electron diffraction Refraction

12 The unit of Planck’s constant is

Volt J s J s⁻¹ eV

13 Which one is most energetic?

γ-rays X-rays Ultraviolet rays Visible light

14 The total amount of energy radiated per unit area of a cavity radiator per unit time is directly proportional to

T T² T³ T⁴

15 Planck’s constant h has the same units as that of

Linear momentum Angular momentum Torque Power

16 The photoelectric effect was explained by

Hertz Einstein Rutherford Bohr

17 All motions are

Absolute Uniform Relative Variable

18 The rest mass energy of an electron in MeV is equal to

0.511 0.611 0.902 1.02

19 An observer shoots parallel to a meter stick at relativistic speed and finds its length is

Greater than one meter Less than one meter One meter None

20 Linear momentum of a photon is

Zero hf/c² hf/c c²/hf

21 A photon with energy greater than 1.02 MeV can interact with matter as

Photoelectric effect Compton effect Pair production Pair annihilation

22 Stopping potential for a metal surface in photoelectric emission depends on

Threshold frequency for the metal Intensity of incident light Frequency of incident light and work function None

23 As the temperature of a black body is raised, the wavelength corresponding to maximum intensity

Shifts to longer wavelength Shifts to shorter wavelength Remains the same Shifts to both longer and shorter

24 The name "photon" for quantum of light was proposed by

Ampere Planck Thomson Einstein

25 A photon is a

Unit of energy Positively charged particle Packet of electromagnetic radiation Unit of wavelength

26 The phenomenon where light ejects electrons from a material surface is called

X-ray emission Compton effect Photoelectric effect Nuclear fission

27 The minimum energy needed for a photon to create an electron-positron pair is

1.02 keV 0.51 keV 0.51 MeV 1.02 MeV

28 Davisson and Germer’s experiment indicated

Electron refraction Electron polarization Electron reflection Electron diffraction

29 In Davisson-Germer experiment, diffracted electrons from a crystal show

Particle property Wave property Light property Quantum property

30 In an electron microscope, electric and magnetic fields are used as

Electromagnetic gun Source of EM waves Deflect charged particles Converging source of electrons

31 The uncertainty in momentum and position is due to its

Property of matter and radiation Two-dimensional motion Emission of certain wavelength Very high velocity

32 The energy radiated is directly proportional to the fourth power of Kelvin’s temperature in

Wien’s law Rayleigh-Jeans law Stefan’s law Planck’s law

33 The antiparticle of an electron is

Proton Positron Meson Neutron

34 The reverse process of pair production is

Annihilation Materialization Fission Fusion

35 The decrease in length with speed was explained by

Einstein Lorentz Bohr None

36 All motion in the universe is

Absolute Uniform Variable Relative

37 Pair production is not possible in

Air Water Glass Vacuum

38 The minimum energy required for pair production is

10.2 MeV 1.02 MeV 102 MeV None

39 The relation λ_max T = constant is

Wien’s law Planck’s law Stefan’s law None

40 The quantity √(1 − v²/c²) is always

Greater than one Less than one Equal to one None

41 Who proposed the idea of matter waves?

De Broglie Planck Einstein Huygens

42 The Stefan-Boltzmann constant has the value

5.67 × 10³ Wm⁻²K⁻⁴ 5.67 × 10⁶ Wm⁻²K⁻⁴ 5.67 × 10⁻⁶ Wm⁻²K⁻⁴ 5.67 × 10⁻⁸ Wm⁻²K⁻⁴

43 The energy of a photon of radio waves is about

10⁶ eV 10⁻⁴ eV 10⁻¹⁰ eV 10⁻¹² eV

44 The idea of energy quantization was proposed by

Einstein Max Planck Compton None

45 An application of the photoelectric effect is

Photo diode Photo transistor Photocell None

46 In the Compton effect, the conserved quantities are

Energy Momentum Both None

47 The equation for pair production is

hf = 2m₀c² − KE(e⁻) + KE(e⁺) hf = 2m₀c² + KE(e⁻) + KE(e⁺) hf = 2m₀c² + KE(e⁺) + KE(e⁺) hf = 2m₀c² + KE(e⁺) + KE(e⁺)

48 Which has the same dimension as h/m₀c?

Length Time Mass None

49 Photon "A" has twice the energy of photon "B". Their momentum ratio (A:B) is

4:1 2:1 1:2 None

50 The electron’s antiparticle is

Proton Photon Positron Deuteron

51 The rest mass of a photon is

Infinite Zero hf/c² Undefined

52 Which phenomenon confirms the wave nature of electrons?

Photoelectric effect Compton scattering Davisson-Germer experiment Pair production

53 The energy of a photon is directly proportional to its

Wavelength Frequency Speed Amplitude

54 Which law explains the shift in blackbody radiation peak with temperature?

Stefan’s law Wien’s law Planck’s law Rayleigh-Jeans law

55 The photoelectric effect demonstrates light’s

Wave nature Particle nature Dual nature None

56 The Compton wavelength is a property of

Photons Electrons Protons All particles

57 Which is not a quantum phenomenon?

Photoelectric effect Blackbody radiation Pair production Classical mechanics

58 The concept of "matter waves" applies to

Photons only Electrons only Macroscopic objects All matter

59 The work function in photoelectric emission is the

Minimum energy to eject an electron Kinetic energy of emitted electrons Photon energy Potential difference

60 Which principle states that position and momentum cannot both be precisely known?

Pauli exclusion Heisenberg uncertainty Planck’s quantum De Broglie’s wave

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Chapter 15: Atomic Spectra