Photoelectric Effect Questions and Answers

Carbon, 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 =

Calculate 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?

1. 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.

Two 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?

2. 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

An 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?

When ultraviolet light with a wavelength of 400 nm falls on a certain metal surface, the maximum kinetic energy of the emitted photoelectrons is 1.10 eV. What is the maximum kinetic energy Ko of the photoelectrons when light of wavelength 260 nm falls on the same surface?

If h/mc is very very large compared to the wavelength of the radiation that you're sending in to hit the electron, then this shift in wavelength is going to be...... small infinity Zero very high

Tungsten has electron shell binding energies of: K = 69 keV, L = 12 keV, M = 2 keV. A 60 keV electron striking a tungsten target could cause emission of characteristic x-rays of which of the following energies (keV)? a) 69, 60, 9 b) 69, 12, 2 c) 60, 12, 2 d) 10,2

Calculate the speed of the fastest photoelectron emitted from tungsten surface when irradiated with photons of energy 5.8 eV. [Photoelectric work function of tungsten = 4.5 eV]

The threshold wavelength of photoelectric emission from a material is 550 nm. Photoelectrons will be emitted when this material is illuminated with monochromatic radiation from a 0.10 W infrared lamp 100 W infrared lamp 0.10 W ultraviolet lamp 100 W ultraviolet lamp

Photons of frequency, v, fall on metal surface for which the threshold of frequency is ν. Then A. All ejected electrons have the same kinetic energy, h(ν – ν₀). B. The ejected electrons have a distribution of kinetic energy from zero to h(ν - ν₀) C. The most energetic electron has kinetic energy hν D. The average kinetic energy of ejected electrons is h(ν - ν₀).

The Sun has a power of P = 3.85 x 1026 Watts. The Earth is a distance of (on average) 1.49 x 108 km away from the Sun. A solar sail is a distance R = 1.50 x 107 km away from the Sun. What pressure does the light exert on the sail? You can assume that the sail is not being blocked by the Earth in anyway. You can assume the system is completely reflective. Make sure to put your answer in terms of mPa (milliPascal) and include appropriate significant figures.