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प्रश्न
A student wants to use two p-n junction diodes to convert alternating current into direct current. Draw the labelled circuit diagram she would use and explain how it works.
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उत्तर
The student will use a full wave rectifier.
Two diodes are used to give rectified O/P corresponding to both positive as well as negative half cycles.
When the voltage at A with respect to the centre tap is positive, and the voltage at B is negative. Then, D1 is forward biased and D2 is reversed biased. Hence, D1 conducts and D2 does not.
When the voltage of A becomes negative, then B becomes + ve. Therefore, D1 does not conduct and D2 conducts. Hence, we obtain output voltage during both the positive as well as negative half of cycle.
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संबंधित प्रश्न
Explain briefly with the help of necessary diagrams, the forward biasing of a p-n junction diode. Also draw characteristic curves.
Explain, with the help of a circuit diagram, the working of n-p-n transistor as a common emitter amplifier.
When a p-n junction is reverse-biased, the current becomes almost constant at 25 µA. When it is forward-biased at 200 mV, a current of 75 µA is obtained. Find the magnitude of diffusion current when the diode is
(a) unbiased,
(b) reverse-biased at 200 mV and
(c) forward-biased at 200 mV.
Consider a p-n junction diode having the characteristic \[i - i_0 ( e^{eV/kT} - 1) \text{ where } i_0 = 20\mu A\] . The diode is operated at T = 300 K . (a) Find the current through the diode when a voltage of 300 mV is applied across it in forward bias. (b) At what voltage does the current double?
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(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
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