Photoelectric Effect Questions and Answers

Physics
Photoelectric EffectThe arrows in the diagram is likely to result in continuous emission spectrum not predictable as there are to many energy states involved absorption spectrum line spectrum

Physics
Photoelectric Effect4. During a photoelectric effect experiment, light possessing 2.53 eV of energy is incident on the photosensitive material. Electrons are emitted with an energy of 1.71 eV of energy. What is the work function of the material?
2.53 eV
4.24 eV
1.71 eV
0.82 eV

Physics
Photoelectric Effect3. The frequency of orange light is 5.01 x 10¹4 Hz. How much-energy does a photon of orange light carry? (h= 6.626 x 10-34 J-s; 1 eV = 1.60 x 10-1⁹ J)
5.43 eV
3.32 eV
2.07 eV
7.56 eV

Physics
Photoelectric Effect9. During a photoelectric effect experiment, light possessing 2.53 eV of energy is incident on the photosensitive material. The work function of the material is 0.78 eV What is the kinetic energy of the emitted electrons?
5.30 x 10-19 J
4.05 x 10-19 J
1.25 x 10-19 J
2.80 x 10-19 J

Physics
Photoelectric Effect2. What is the de Broglie wavelength of a 2.89 x 10-28 kg particle moving at 3.00 x 108 m/s? (h= 6.626 x 10-34 J-s)
4.45 x 10-15 m
7.65 x 10-15 m
7.99 x 10-15 m
9.12 x 10-15 m

Physics
Photoelectric Effect1. What is the de Broglie wavelength of a particle with a momentum of 1.11 x 10-10 kg-m/s? (h= 6.626 x 10^-34 J-s)
5.17 x 10-24 m
3.78 x 10-24 m
5.96 x 10-24 m
6.79 x 10-24 m

Physics
Photoelectric Effect2. The frequency of violet light is 7.5 x 10¹4 Hz. How much energy does a photon of violet light carry? (h= 6.626 x 10-34 J-s; 1 eV = 1.60 x 10-¹⁹ J)
3.14 x 10³ ev
2.73 x 10-² ev
0.148 eV
3.11 eV

Physics
Photoelectric EffectA cylindrical rod of some laser material 5 x 10-2m long and 10-2m in diameter contains 2 × 1025 ion per m³. If on excitation all the ions are in the upper energy level and de-excite simultaneously emitting photons in the same direction, calculate the maximum energy contained in a pulse of radiation of wavelength 6.6 x 10-7m . If the pulse lasts for 10-7 s, calculate the average power of the laser during the pulse
A. 33.55 W
B. 43.55 W
C. 23.55 W
D. 29.55 W

Physics
Photoelectric EffectA Laser light of wavelength 600nm is used to weld retina detachment. If a Laser pulse of width 60ms and 0.5kW is used the approximate number of photons in the pulse are:
A. 10^20
B. 10^18
C. 10^22
D. 10^19

Physics
Photoelectric EffectIn Young's double slit experiment the separation d between the slits is 2mm, the wavelength of light used is 5896A and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the angular fringe width to 0.21° (with same > and D) the separation between the slits needs to be changed to.

Physics
Photoelectric EffectCarbon, silicon and germanium have four valence
electrons each. These are characterised by valence
and conduction bands separated by energy band
gap respectively equal to (Eg)c, (Eg) si and
(Eg) Ge .Which of the following statements is true?
A
B (Eg)c< (Eg) Ge> (Eg) Si
C
(Eg) Si < (Eg) Ge < (Eg)c
D
(Eg)c (Eg) Si > (Eg) Ge
>
(Eg)c = (Eg) Si
= (Eg)G
=

Physics
Photoelectric EffectCalculate the maximum wavelength, Amax, of electromagnetic radiation that could eject electrons from the surface of aluminum, which has a work function of 6.50 x 10^-19 J.
If the maximum speed of the emitted photoelectrons is 2.30 x 10^6 m/s, what wavelength of electromagnetic radiation struck the surface and caused the ejection of the photoelectrons?

Physics
Photoelectric Effect1. Which of the following is true about the Joly Photometer?
You can use the Joly Photometer to measure the absolute brightness (in W/m² for example) of a light source.
You can use it to measure the relative brightness of the two light sources.
The Joly Photometer is made of a solid block of wax
The Joly Photometer is complicated to build and expensive.

Physics
Photoelectric EffectTwo stars, both of which behave like ideal blackbodies, radiate the same total energy per second. The cooler one has a surface temperature T and 3.5 times the diameter of the hotter star.
What is the temperature of the hotter star in terms of T?
What is the ratio of the peak-intensity wavelength of the hot star to the peak-intensity wavelength of the cool star?

Physics
Photoelectric Effect2. Consider a metal exposed to light of wavelength 600 nm. The maximum energy of the electron doubles when light of wavelength 400 nm is used. Find the work function in eV. Ans: Let the maximum energies of emitted electrons are K₁ and K₂ when 600 nm and 400 nm visible light are used according to question

Physics
Photoelectric EffectAn electron microscope is using a 1.00-keV electron beam. An atom has a diameter of about 10-10 meters.
Can an individual atom theoretically be resolved using this electron microscope?