College Physics (10th Edition)
10th Edition
ISBN: 9780321902788
Author: Hugh D. Young, Philip W. Adams, Raymond Joseph Chastain
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 28, Problem 9CQ
To determine
Whether it is possible to make a phosphor that converts visible light
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
What is the frequency (in Hz) of an ultraviolet photon with wavelength 139 nm? Express your answer in scientific notation.
For years, exposure to ultra-violet radiation from prolonged time in the sun has been the major
identified cause of skin cancer. New research is showing that ultra-violet is not the only type of
radiation from the sun that can increase the risk of skin cancer. Rates of skin cancer among
pilots are twice that of non-pilots, but the glass used in planes blocks most the ultra-violet
radiation. Pilots are also exposed to x-rays from the sun during flight. The x-rays that pilots are
exposed to in one day of work are equivalent to a chest x-ray. Although getting an x-ray for
medical reasons is believed to be safe, researchers believe that the frequent exposer that pilots
experience increases their risk for skin cancer.
The Electromagnetic Spectrum
IMHE
IGHE
Fregiency r
10
10 10
1e 10 10" 10
10
10"
Camme
wened
Wwwdengih in 10 10 10 1 10 10 10 10
o* 10* 10 10 10 19" 1e 10 1o
Ikm
Imm
Tum
Inm
Ipm
Use your knowledge of the electromagnetic spectrum to support the claim that pilots are at a
greater…
Oxygenated hemoglobin absorbs weakly in the red (hence its red color) and strongly in the near infrared, whereas deoxygenated hemoglobin has the opposite absorption. This fact is used in a “pulse oximeter” to measure oxygen saturation in arterial blood. The device clips onto a person’s finger and has two light emitting diodes (i.e., LEDs) – a red (660nm) and an infrared (940nm) – and a photocell that detects the amount of light transmitted through the finger at each wavelength
a)Determine the frequency of each of these light sources.
b)If the intensity of the beams is 1.00X10-6 Watts/m2 , calculate the peak electric and magnetic fields of the light supplied by the LEDs.
Chapter 28 Solutions
College Physics (10th Edition)
Ch. 28 - Prob. 1CQCh. 28 - Prob. 2CQCh. 28 - Prob. 3CQCh. 28 - Prob. 4CQCh. 28 - Prob. 5CQCh. 28 - Prob. 6CQCh. 28 - Prob. 7CQCh. 28 - Prob. 8CQCh. 28 - Prob. 9CQCh. 28 - Prob. 10CQ
Ch. 28 - Prob. 11CQCh. 28 - Prob. 12CQCh. 28 - Prob. 1MCPCh. 28 - Prob. 2MCPCh. 28 - Prob. 3MCPCh. 28 - Prob. 4MCPCh. 28 - Prob. 5MCPCh. 28 - Prob. 6MCPCh. 28 - Prob. 7MCPCh. 28 - Prob. 8MCPCh. 28 - Prob. 9MCPCh. 28 - Prob. 10MCPCh. 28 - Prob. 11MCPCh. 28 - Prob. 12MCPCh. 28 - Prob. 1PCh. 28 - Prob. 2PCh. 28 - Prob. 3PCh. 28 - Prob. 4PCh. 28 - Prob. 5PCh. 28 - Prob. 6PCh. 28 - Prob. 7PCh. 28 - Prob. 8PCh. 28 - Prob. 9PCh. 28 - Prob. 10PCh. 28 - Prob. 11PCh. 28 - Prob. 12PCh. 28 - Prob. 13PCh. 28 - Prob. 14PCh. 28 - Prob. 15PCh. 28 - Prob. 16PCh. 28 - Prob. 17PCh. 28 - Prob. 18PCh. 28 - Prob. 19PCh. 28 - Prob. 20PCh. 28 - Prob. 21PCh. 28 - Prob. 22PCh. 28 - Prob. 23PCh. 28 - Prob. 24PCh. 28 - Prob. 25PCh. 28 - Prob. 26PCh. 28 - Prob. 27PCh. 28 - Prob. 28PCh. 28 - Prob. 29PCh. 28 - Prob. 30PCh. 28 - Prob. 31PCh. 28 - Prob. 32PCh. 28 - Prob. 33PCh. 28 - Prob. 34PCh. 28 - Prob. 35PCh. 28 - Prob. 36PCh. 28 - Prob. 37PCh. 28 - Prob. 38PCh. 28 - Prob. 39PCh. 28 - Prob. 40PCh. 28 - Prob. 41PCh. 28 - Prob. 42PCh. 28 - Prob. 43PCh. 28 - Prob. 44PCh. 28 - Prob. 45PCh. 28 - Prob. 46PCh. 28 - Prob. 47PCh. 28 - Prob. 48PCh. 28 - Prob. 49PCh. 28 - Prob. 50GPCh. 28 - Prob. 51GPCh. 28 - Prob. 52GPCh. 28 - Prob. 53GPCh. 28 - Prob. 54GPCh. 28 - Prob. 55GPCh. 28 - Prob. 56GPCh. 28 - Prob. 57GPCh. 28 - Prob. 58GPCh. 28 - Prob. 59GPCh. 28 - Prob. 61GPCh. 28 - Prob. 62GPCh. 28 - Prob. 63GPCh. 28 - Prob. 64GPCh. 28 - Prob. 65GPCh. 28 - Prob. 66PPCh. 28 - Prob. 67PPCh. 28 - Prob. 68PPCh. 28 - Prob. 69PPCh. 28 - Prob. 70PPCh. 28 - Prob. 71PPCh. 28 - Prob. 72PPCh. 28 - Prob. 73PPCh. 28 - Prob. 74PP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Human skin is opaque to visible light but transparent to X-rays. Why?arrow_forwardWhat is the energy (in eV) of a 450-nm photon of blue light?Give your answers to three significant figures.arrow_forwardWhat is the wavelength, in nm, of a photon with energy (a) 0.30 eV, (b) 3.0 eV, and (c) 30 eV? For each, is this wavelength visible light, ultraviolet, or infrared?arrow_forward
- Determine the energy of a 891 nm photon in eV. Express your answer in three decimal places.arrow_forwardWhen a photoconductor is exposed to light a. less current flows through it b.its resistance increases c.it becomes less conductive d.it becomes more conductive e.it acts like an insulatorarrow_forwardWhat is the energy of a 858 nm photon in eV? (Note: Planck's constant for eV units is 4.135 1o 15 ev's)arrow_forward
- Compare the energies of photons emitted by two radio stations, operating at 92 MHz (FM) and 1500 kHz (MW)? A 7.25x10-s M solution of potassium permanganate has a transmittance of 44.1% when measured in a 2.10 cm cell at a wavelength of 525 nm. Calculate a. the absorbance of this solution and b. the molar absorptivity of KMNO4arrow_forwardSuppose you are standing in the dark and facing a 20-W LED bulb 100 meters away. If the diameter of your pupils is about 8 mm under these conditions, about how many photons of visible light enter your eye every second? (Hint: the answer is about 6 billion photons per second)arrow_forward(a) Calculate the wavelength of light in vacuum that has a frequency of 5.06 x 10 18 nm (b) What is its wavelength in flint glass? nm (c) Calculate the energy of one photon of such light in vacuum. Express the answer in electron volts. eV (d) Does the energy of the photon change when it enters the flint glass? The energy of the photon changes. The energy of the photon does not change. Hz. Explain.arrow_forward
- The temperature of an object is 310 K. The electromagnetic radiation emitted by this object is: O in the ultraviolet region of the spectrum. O in the microwave region of the spectrum. O in the visible region of the spectrum (red). O in the visible region of the spectrum (yellow). O in the visible region of the spectrum (violet).. O in the infrared region of the spectrum.arrow_forwardLight Absorption (Photovoltaics / Mertens) 1. What is the photon energy of light at the wavelength λ = 560 nm in eV? (Planck's constant is 6.6 x 10-34 m2 kg / s) 2. What is the penetration depth of light at the wavelength λ = 560nm in c-Si (crystalline Si) and a-Si (amorphous Si)? 3. Light with a wavelength of 600 nm and an irradiance of E= 500 W/m 2 impinges vertically on to a semiconductor of amorphous silicon. At this wavelength the material has a refractive index of 4.6. a. What portion of the light is reflected at the semiconductor surface? b. What thickness and what refractive index should an anti-reflective film possess in an ideal case? Assume SiN is used as an anti-reflective film. What should the thickness of the film be in this case? (you need to look up the refractive index of SIN) 4. Given is a c-Si cell of thickness d = 140 micormeters that is illuminated by light with a strength of E= 1000 W/m 2 ,( a = 100/cm; n = 3.3; λ = 1000 nm). a. How large is the penetration depth…arrow_forwardHow many photons are emitted per second from a semiconductor laser that emits 0.75 mW of light at wavelength 852 nm?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningAn Introduction to Physical SciencePhysicsISBN:9781305079137Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar TorresPublisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
An Introduction to Physical Science
Physics
ISBN:9781305079137
Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar Torres
Publisher:Cengage Learning