Concept explainers
A cathode ray tube (CRT) is a device that produces a focused beam of electrons in a vacuum. The electrons strike a phosphor-coated glass screen at the end of the tube, which produces a blight spot of light. The position of the bright spot of light on the screen can be adjusted by deflecting the electrons with electrical fields, magnetic fields, or both. Although the CRT tube was once commonly found in televisions, computer displays, and oscilloscopes, newer appliances use a liquid crystal display (LCD) or plasma screen. You still may come across a CRT in your study of science. Consider a CRT with an electron beam average current of
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
University Physics Volume 2
Additional Science Textbook Solutions
The Cosmic Perspective (8th Edition)
Sears And Zemansky's University Physics With Modern Physics
University Physics (14th Edition)
College Physics (10th Edition)
Essential University Physics: Volume 2 (3rd Edition)
Essential University Physics: Volume 1 (3rd Edition)
- Professor Edward Ney was the founder of infrared astronomy at the University of Minnesota. In his later years, he wore an artificial pacemaker. Always an experimentalist, Ney often held a strong laboratory magnet near his chest to see what effect it had on his pacemaker. Perhaps he was using the magnet to throw switches that control different modes of operation. An admiring student (without an artificial pacemaker) thought it would be fun to imitate this great man by holding a strong magnet to his own chest. The natural pacemaker of the heart (known as the sinoatrial node) carries a current of about 0.5 mA. Estimate the magnetic force exerted on a natural pacemaker by a strong magnet held to the chest. How do you think the student might have felt during the experiment? Explain your geometric assumptions. Hints: See Table 30.1 (page 941) to estimate the magnetic field, and assume the field is roughly uniform. Use Figure P30.58 to estimate the size of the sinoatrial node; your heart is about the size of your fist. FIGURE P30.58arrow_forwardSolvearrow_forwardhelparrow_forward
- A particle passes through a mass spectrometer as illustratedin Figure P19.15. The electric field between the plates ofthe velocity selector has a magnitude of 8 250 V/m, and themagnetic fields in both the velocity selector and the deflectionchamber have magnitudes of 0.093 1 T. In the deflectionchamber the particle strikes a photographic plate 39.6 cmremoved from its exit point after traveling in a semicircle.(a) What is the mass - to - charge ratio of the particle? (b) Whatis the mass of the particle if it is doubly ionized? (c) What isits identity, assuming it’s an element?arrow_forwardSolve with the same answers and with stepsarrow_forwardA particular species of copepod, a small marine crustacean, emits a flash of light consisting of 1.4 x 1010 photons at a wavelength of 490 nm. The flash lasts for 2.4 s. What is the power of the flash?arrow_forward
- Due to collisions in a wire, the electron’s overall speed or drift speed is very slow (about 1x10-5 m/s). How then does a light turn on almost instantly when the switch is flipped?arrow_forwardAn Electromagnetic wave of v = 5 MHz passes from vacuum into the dielectric medium with permittivity E, = 4, then: The wavelength is doubled and the frequency becomes half The wavelength and frequency both remain unchanged The wavelength is halved and the frequency remains unchanged The wavelength is doubled and the frequency is halvedarrow_forwardIn experiment 8, we measure the current drawn from a signal generator. According to the multimeter below, what is the maximum current supplied by the signal generator? Choose the closest value to your answer. 6. 4. 8 L.. CAT 30N max 2 10 ~ויויויוי 2 2 6 4 2 8. 3 10 8 10 METRA max 2arrow_forward
- A 13.0-mW helium-neon laser emits a beam of circular cross section with a diameter of 3.10 mm. (a) Find the maximum electric field in the beam. (b) What total energy is contained in a 1.00-m length of the beam? (c) Find the momentum carried by a 1.00-m length of the beam. Step 1 We will find the reasonable size of the electric field in a beam of bright light. At the speed of light, only a small fraction of a joule is contained in a meter-length beam. The momentum of the beam is a very small fraction of a kg. m/s. Light is described by energy and momentum but possesses no mass. Step 2 We will use the equation relating the intensity of light to the wave amplitude. From the definition of intensity, we can find the energy content of the beam of light. Then the relationship between momentum, energy, and the speed of light will give us the momentum of a length of the beam. Step 3 The intensity of light I is given by the average magnitude of the Poynting vector. We have 2 I = S₂ avg P Tr²…arrow_forwardMammography is an x-ray imaging procedure for breast cancer diagnosis and screening. Assume that 20ke V x-ray is used in mammography. Also assume that the breast of a patient is 6 cm in thickness (soft tissue), and the propagation speed of x-ray photons in soft tissue is about the same as in vacuum. How long will it take for x- ray photons to travel through the breast?arrow_forwardThe spectrum of a glowing filament has its peak at a wavelength of 1200 nm. What is the temperature of the filament, in °C?arrow_forward
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College