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Is light emitting diodes emit visible light when forward biased?
Wiki User
∙ 12y ago
It depends on the particular LED. Some of them emit infrared light. But, yes, emission occurs when forward-biased.
Wiki User
∙ 12y ago
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For what does LED lights stand for?
Light Emitting Diodes
Why diode drop 0.7v ouccuer in forward baised?
Diodes normally drop between 0.2 and 3.5 volts in the forward bias direction, depending on type, and forward current. The word "ouccuer" is not understood". Please restate the question.
Why ordinary diodes dont work properly At high frequencies?
Because of stray capacitance. At very high frequencies, the inter-electrode capacitance has a low enough impedance that the diode no longer cuts off when reverse-biased, there is still significant conduction via capacitive coupling. High-frequency diodes are constructed so as to minimize this capacitance.
Are diodes polarised?
Yes, diodes are very polarity sensitive. They conduct in one direction, the forward bias state, where the anode is more positive than the cathode, and they do not conduct in the other direction, the reverse bias state, where the cathode is more positive than the anode. (Assuming you do not exceed forward current or reverse voltage limits.) This is how diodes "rectify", i.e. convert from AC to DC.This is for normal diodes. Zener diodes are different. They conduct in both directions, but at different voltages. The forward voltage is similar to a normal diode, typically around 0.6V to 1.4V, while the reverse voltage is higher, such as 5.6V, which is how a zener diode can be used in a voltage regulator circuit.If, however, when you say "polarised", you mean the action of "polarising" an automobile's electrical system, do not even think about it. That technique is no longer necessary since the advent of the alternator. Besides, that technique involves shorting out the battery, which has always been a highly dangerous operation.
What is the purpose of the light-emitting diod?
Light Emitting Diodes (or LED's) serve many purposes, such as statuses (EG Computer is powered on, PC is reading from Hard disk (Power and HDD LED's)). They can also be used to display messages (LED Boards) New age brighter LED's are used in the Audi and BMW cars as sidelights. 4 L1GH7 3M1771N6 D10D35 1S C001
Why current flow from cathode to anode in zener diode?
First off, I don't know if by current flow you mean conventional current flow or electron current flow. You realize they are in opposite directions and most electronics engineers use conventional current flow in circuit analysis.Ignoring this, I will assume your real question is "Why does current flow backwards in zener diodes compared to ordinary diodes?" The answer is that zener diodes are not operated in the forward biased range as are ordinary diodes, instead they are operated in the reverse biased range. When reverse biased enough any diode reaches breakdown voltage and suddenly conducts. Most ordinary diodes can be destroyed by breakdown, but zener diodes are designed to tolerate it. In zener diodes, this breakdown is referred to as "zener breakdown" and the voltage it happens at the "zener voltage".Low voltage zener diodes can still be used in the forward biased mode, like ordinary diodes. However most high voltage zener diodes have a "blocking diode" that is not documented on the data sheet to block forward biased operation. "Blocking diodes" are simply ordinary diodes wired in series with the zener; when the zener would be forward biased they are reverse biased (and thus blocking current), when the zener would be reverse biased they are forward biased.
Why semiconductor photo-diodes are reverse biased?
Because if you forward-biased them they would always conduct, even in total darkness.
What are the vi characteristics of ideal diodes?
Zero current flow when reverse biased, zero voltage drop when forward biased.
A diode is a perfect short when it is forward biased True or False?
A forward biased diode is not a complete short. Depending on it's design, it will have some forward voltage drop. Silicon diodes normally hafe a drop around .7 V, germanium have a drop around .2V. Some of the newer Schottky diodes fall in between. Selenium diodes have a greater FWD drop.
What is maximum forward current in case of diodes?
the maximum amount of current that a forward-biased diode can withstand before burning out or being seriously degraded.
For what does LED lights stand for?
Light Emitting Diodes
Why are light emitting diodes bad?
They aren't bad.
What is a full form of led?
Light Emitting Diodes.
What has the author Joshua T Hall written?
Joshua T. Hall has written: 'Light-emitting diodes and optoelectronics' -- subject(s): Light emitting diodes, Optoelectronic devices
What are examples of diodes?
There are so many different types of diodes. Some of the common examples include light emitting diodes, silicon diodes, zener diodes and so many more.
Where did Light Emitting Diodes get made?
They make them in many different places.
Why does an LED emit light when forward biased?
A special semiconductor material is used in Light Emitting Diodes (LED). When an LED is forward biased, the anode is connected to positive and cathode is connected to negative terminal of the supply, then current flows through the LED, just like in a regular diode. The electrons in the special semiconductor are excited, and when they return to 'normal' state, they give off energy in the form of photons (light rays). One such semiconductor material which is commonly used is gallium arsenide. Note: the photons are not necessarily in the visible light spectrum. The remote control for your television set or DVD player most likely has an infrared LED, to transmit information to the TV.
