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... Light-emitting diodes (LEDs) convert electrical energy into light energy. They emit radiation (photons) of visible wavelengths when they are “forward biased” (i.e. when the voltage between the p side and the n-side is above the “turn-on” voltage). This is caused by electrons from the “n” region in t ...
... Light-emitting diodes (LEDs) convert electrical energy into light energy. They emit radiation (photons) of visible wavelengths when they are “forward biased” (i.e. when the voltage between the p side and the n-side is above the “turn-on” voltage). This is caused by electrons from the “n” region in t ...
Text Questions
... 4) Why must two arrows within a single block of an orbital diagram be written in opposite (up and down) directions? ...
... 4) Why must two arrows within a single block of an orbital diagram be written in opposite (up and down) directions? ...
Photoelectric Effect - Kansas State University
... which automatically turn on the street lights when it gets dark to the receiving end of the scanners at the grocery store check out counter to the detectors in a CD player. All of these devices work because light striking a material deposits energy in that material and causes a change in the motion ...
... which automatically turn on the street lights when it gets dark to the receiving end of the scanners at the grocery store check out counter to the detectors in a CD player. All of these devices work because light striking a material deposits energy in that material and causes a change in the motion ...
e/m Experiment - sestechno.com
... on Thomson’s method. The e/m-tube is bulb-like and contains a filament, a cathode, a grid, a pair of deflection plates and an anode. The tube is filled with helium at a very low pressure. Some of the electrons emitted by the cathode collide with helium atoms which get excited and radiate visible lig ...
... on Thomson’s method. The e/m-tube is bulb-like and contains a filament, a cathode, a grid, a pair of deflection plates and an anode. The tube is filled with helium at a very low pressure. Some of the electrons emitted by the cathode collide with helium atoms which get excited and radiate visible lig ...
Study Notes for Test 1
... so each pulse in US takes 1/120 sec The higher the Hz, the less time it would take for a pulse 32. What is a focusing cup? It is a metal cup with a negative charge (repells electrons), and is used to redirect and focus the electrons onto a focal spot (anode) 33. Why is the tungsten disc of anode rot ...
... so each pulse in US takes 1/120 sec The higher the Hz, the less time it would take for a pulse 32. What is a focusing cup? It is a metal cup with a negative charge (repells electrons), and is used to redirect and focus the electrons onto a focal spot (anode) 33. Why is the tungsten disc of anode rot ...
Photomultiplier
Photomultiplier tubes (photomultipliers or PMTs for short), members of the class of vacuum tubes, and more specifically vacuum phototubes, are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. These detectors multiply the current produced by incident light by as much as 100 million times (i.e., 160 dB), in multiple dynode stages, enabling (for example) individual photons to be detected when the incident flux of light is very low. Unlike most vacuum tubes, they are not obsolete.The combination of high gain, low noise, high frequency response or, equivalently, ultra-fast response, and large area of collection has maintained photomultipliers an essential place in nuclear and particle physics, astronomy, medical diagnostics including blood tests, medical imaging, motion picture film scanning (telecine), radar jamming, and high-end image scanners known as drum scanners. Elements of photomultiplier technology, when integrated differently, are the basis of night vision devices.Semiconductor devices, particularly avalanche photodiodes, are alternatives to photomultipliers; however, photomultipliers are uniquely well-suited for applications requiring low-noise, high-sensitivity detection of light that is imperfectly collimated.