Quiz: Chapter 13 - Modern Physics

1 An observer moving at relativistic speed measures a meter stick as ______

Greater than one meter Less than one meter One meter None of these

2 The linear momentum of a photon is ______

Zero hf/c² hf/c c²/hf

3 A photon with energy >1.02 MeV interacts via ______

Photoelectric effect Compton effect Pair production Pair annihilation

4 Stopping potential in photoelectric effect depends on ______

Threshold frequency Light intensity Incident frequency & work function None

5 As blackbody temperature increases, λ_max ______

Shifts to longer λ Shifts to shorter λ Remains same Shifts both ways

6 The term "photon" was proposed by ______

Ampere Planck Thomson Einstein

7 A photon is a ______

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

8 Light ejecting electrons from a surface is called ______

X-ray emission Compton effect Photoelectric effect Nuclear fission

9 Minimum energy for electron-positron pair production is ______

1.02 KeV 0.51 KeV 0.51 MeV 1.02 MeV

10 Davisson-Germer experiment demonstrated ______

Electron refraction Electron polarization Electron reflection Electron diffraction

11 In Davisson-Germer experiment, diffracted electrons show ______

Particle property Wave property Light property Quantum property

12 Electron microscopes use fields to ______

Act as EM guns Source EM waves Deflect particles Converge electrons

13 Heisenberg’s uncertainty principle arises from ______

Matter-wave duality 2D motion Specific wavelengths High velocity

14 Energy radiated ∝ T⁴ is ______ law

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

15 The antiparticle of an electron is ______

Proton Positron Meson Neutron

16 Reverse of pair production is ______

Annihilation Materialization Fission Fusion

17 Length contraction was explained by ______

Einstein Lorentz Bohr None

18 All motion is ______

Absolute Uniform Variable Relative

19 Pair production is impossible in ______

Air Water Glass Vacuum

20 Minimum energy for pair production is ______

10.2 MeV 1.02 MeV 102 MeV None

21 λ_max T = constant is ______ law

Wien’s Planck’s Stefan’s None

22 √(1−v²/c²) is always ______

>1 <1 =1 None

23 Matter waves were proposed by ______

De Broglie Planck Einstein Huygens

24 Stefan-Boltzmann constant value is

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

25 Radio wave photon energy is ~ eV

10⁶ 10⁻⁴ 10⁻¹⁰ 10⁻¹²

26 Quantization of energy was proposed by ______

Einstein Max Planck Compton None

27 Photoelectric effect applications include ______

Photodiode Phototransistor Photocell None

28 In Compton effect, ______ is conserved

Energy Momentum Both None

29 Pair production equation is ______

hf = 2m₀c² + KE(e⁻) + KE(e⁺) hf = 2m₀c² - KE(e⁻) + KE(e⁺) hf = 2m₀c² + KE(e⁻) - KE(e⁺) None

30 h/m₀c has the same dimension as ______

Length Time Mass None

31 If photon A has 2× energy of B, momentum ratio A:B is ______

4:1 2:1 1:2 None

32 The antiparticle of an electron is ______

Proton Photon Positron Deuteron

33 Einstein’s mass-energy relation is ______

E = mc E = mc³ E = mc² E = m²c²

34 A positron has ______

Mass = electron Charge = electron Mass = electron, charge opposite Mass = proton

35 e⁻ + e⁺ annihilation produces ______ photons

1 2 3 4

36 X-ray production is the reverse of

Pair production Photoelectric effect Compton effect Annihilation

37 Atomic radius is ~ m

10¹⁰ 10⁻¹⁰ 10⁻¹⁴ 10¹⁴

38 Special relativity was proposed in 1905 by ______

Maxwell De Broglie Bohr Einstein

39 Neutron discovered in 1932 by ______

Bohr Chadwick Dirac Fermi

40 Photon rest mass is ______

Infinite Zero hf mc²

41 Max Compton shift occurs at θ = ______

0° 45° 90° 180°

42 Davisson-Germer experiment showed ______

Interference Polarization Electron diffraction Refraction

43 Electron rest mass energy is ______ MeV

0.511 0.611 0.902 1.02

44 Compton shift Δλ = λ_C at θ = ______

0° 45° 60° 90°

45 Planck’s constant unit is ______

Volt J·s J/s eV

46 Most energetic radiation is ______

γ-rays X-rays UV rays Visible light

47 Cavity radiator energy ∝ ______

T T² T³ T⁴

48 Planck’s constant has same unit as ______

Linear momentum Angular momentum Torque Power

49 Photoelectric effect explained by ______

Hertz Einstein Rutherford Bohr

50 All motion is ______

Absolute Uniform Relative Variable

51 Aldehydes are generally more reactive than ketones because:

Less steric hindrance Less electron donation by alkyl groups Both A and B Neither A nor B

52 Schiff bases are formed by reaction of:

Aldehydes/ketones with primary amines Alcohols with amines Acids with amines Esters with amines

53 Oximes are formed by reaction with:

Hydroxylamine Hydrazine Phenylhydrazine Semicarbazide

54 Hydrazones are formed by reaction with:

Hydroxylamine Hydrazine Phenylhydrazine Both B and C

55 Grignard reagents react with carbonyl compounds to give:

Primary alcohols Secondary alcohols Tertiary alcohols Depends on carbonyl compound

56 Reformatsky reaction involves:

Zn + α-bromoester + carbonyl Mg + alkyl halide + carbonyl Li + alkyl halide + carbonyl Na + ester + carbonyl

57 McLafferty rearrangement is observed in:

NMR spectroscopy IR spectroscopy Mass spectrometry UV spectroscopy

58 Carbonyl compounds show characteristic absorption in IR at:

1600-1700 cm⁻¹ 1700-1750 cm⁻¹ 2500-3000 cm⁻¹ 3200-3600 cm⁻¹

59 Halogenation of ketones occurs at:

α-position β-position γ-position Carbonyl carbon

60 Haloform reaction is used to identify:

All aldehydes All ketones Methyl ketones and acetaldehyde Aromatic aldehydes

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Chapter 13: Modern Physics