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How does Mobile phone work

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  A mobile phone is a part of our life.   But I'm sure you're curious minds have always been struck by such questions as how a mobile phone makes a call, and why there are different generations of mobile communications?   Let's explore the technology behind mobile communications. When you speak on your phone, your voice is picked up by your phone's microphone. The microphone turns your voice into a digital signal with the help of MEMS sensor and IC. The digital signal contains your voice in the form of zeros and ones. An antenna inside the phone receives these zeros and ones and transmits them in the form of electromagnetic waves.   Electromagnetic waves transmit the zeros and ones by altering the wave characteristics, such as the amplitude, frequency, phase, or combinations of these.   For example, in the case of frequency, zero and one are transmitted by using low and high frequencies respectively. So, if you could find a wa...
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سوئچ کے بطور بائپولر ٹرانسلیٹر THE BIPOLAR TRANSISTOR AS A SWITCH

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 THE BIPOLAR TRANSISTOR AS A SWITCH The major application area is switching applications.  When used as an electronic switch, a transistor normally is operated alternately in cutoff and saturation.  In part  (a), the transistor is cut off because the base-emitter junction is not forward biased. In this condition, there is ideally, open between collector and emitter.  In part  (b), the transistor is saturated because the base-emitter junction is forward biased and the base current is large enough to cause the collector current to reach its saturated value. In this condition, there is, ideally, a short between collector and emitter.  Actually, a voltage drop of a few tenths of a volt normally occurs. سوئچ کے بطور بائپولر ٹرانسلیٹر ایپلیکیشن کا اہم علاقہ ایپلی کیشنز کو تبدیل کرنا ہے۔ جب الیکٹرانک سوئچ کے طور پر استعمال ہوتا ہے تو ، عام طور پر ایک ٹرانجسٹر باری باری کٹ آف اور سنترپتی میں چلتا ہے۔ حصے میں (a) ، ٹرانجسٹر منقطع ہوگیا ہے کیونکہ بیس امیٹر ...
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BIPOLAR JUNCTION TRANSISTORS

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  The bipolar junction transistor is constructed with three-doped semiconductor regions separated by two PN junctions.  The three regions are called  a.      Emitter b.      Base c.      Collector.  The two types of bipolar transistors are  (a). One type consists of two N-regions separated by a P-region (NPN),  and the other consists of two P-regions separated by an N-region (PNP).  The PN junction joining the base region and the emitter region is called the base-emitter junction.  The junction joining the base region and the collector region is called the base-collector region. A wire lead connects to each of the three regions.  These leads are labeled E, B, and C for the emitter, base, and collector, respectively. The base material is lightly doped and very narrow compared to the heavily doped emitter and collector materials.  the schematic symbols for the NPN and PNP bipolar transistors. Th...
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  The Light Emitting Diodes (LED) The basic operation of the led is as follows:  When the device is forwarded biased, electron crosses the PN junction from the N-type material and recombine with holes in the P-type material. Recall that those free electrons band and at a higher energy level then holes in the valance band.  When recombination takes place, the recombining electrons release energy in the form of heat and light.  A large exposed surface area on one layer of the semiconductor material permits the photons to be emitted as visible light.  (a) illustrates this process, which is called electroluminescence. The semiconductor materials used in LEDs are gallium arsenide (GaAs), gallium arsenide phosphide (GaAs), and gallium phosphide (GaP).  Silicon and Germanium are not used because they are essentially heated producing material and are very poor at producing light. GaAs LEDs emit infrared (IR) radiation. GaAsP produces either red or yellow light, and...
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Semiconductor device Diode

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  Diode Diode is a semiconductor device. Because of their unique ability to conduct current in only one direction, diode are used in rectifier circuits. Rectification is the process of converting AC to pulsating DC. Diode and its symbol       Half Wave Rectifiers When the sine wave inpu t voltage goes positive, the diode is forward-biased and conducts current to the load resistor. The current produces a voltage across the load, which has same shape as the positive half-cycle of the input voltage. When the input voltage goes negative  during the second half of its cycle, the diode is reversed- biased. There is no current, so the voltage across the load resistor is 0. The net result is that only the positive half cycles of the ac input voltage appears across the load, making the output a pulsating DC voltage. This process is called half wave-rectification ڈایڈ ایک نیم کنڈکٹر ڈیوائس ہے۔   ڈایڈڈ صرف ایک ہی سمت میں کرنٹ...
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Semiconductors سیمی کنڈکٹر

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  Semiconductors Semiconductors are classed below the conductors in their ability to carry current because they have fewer free electrons than do conductors.   Semiconductors are characterized by four valence electrons in their atomic structures.   However, because of their unique characteristics, certain semiconductor materials are the basis for modern electronic devices such as the diode, transistor, and integrated circuit.   Silicon and germanium are common semiconductor materials. سیمی کنڈکٹر کو کرنٹ لے جانے کی صلاحیت میں کنڈیکٹر کے نیچے درجہ بند کیا جاتا ہے کیونکہ ان کے پاس کنڈکٹر کے مقابلے میں الیکٹران کم ہوتے ہیں۔ سیمیکمڈکٹرز کو ان کے جوہری ڈھانچے میں چار والینس الیکٹران کی خصوصیات دی جاتی ہے۔ تاہم ، ان کی انوکھی خصوصیات کی وجہ سے ، کچھ سیمیکمڈکٹر مادے جدید الیکٹرانک آلات جیسے ڈایڈڈ ، ٹرانجسٹر ، اور مربوط سرکٹ کی بنیاد ہیں۔   سیلیکون اور جرمینیم سیمیکمڈکٹر کا عام مادہ ہیں۔    
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First Ten Decimal number change into Binary Code پہلے دس اعشاریہ نمبر کوبائنری کوڈ میں تبدیل کریں

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  First Ten Decimal number change  into Binary Code  پہلے دس اعشاریہ نمبر کوبائنری کوڈ میں تبدیل کریں     Decimal               =                    Binary Code             1                       =                        000 I           2                       =                         00 I0           3                      =                           00II      ...
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