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प्रश्न
Two identical p-n junction may be connected in series with a battery in three ways. The potential difference across the two p-n junctions are equal in
पर्याय
circuit 1 and circuit 2
circuit 2 and circuit 3
circuit 3 and circuit 1
circuit 1 only.
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उत्तर
circuit 2 and circuit 3
In circuit 1, one diode is forward biassed and the other diode is reverse biassed.
The forward-biassed diode offers zero resistance (ideally) to the current flow, so it can be replaced by a short circuit. The voltage drop across the first diode will be zero. The second diode is reverse biassed, so it can be replaced by an open circuit; hence, the voltage drop across this diode will be maximum.
In circuit 2, both the diodes are forward biassed, so they can be replaced by short circuits; hence, the voltage drop across both of them will be minimum and equal.
In circuit 3, both the diodes are reverse biassed, so both can be replaced by open circuits; hence, the voltage drop across both of them will be maximum and equal.
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संबंधित प्रश्न
In an unbiased p-n junction, holes diffuse from the p-region to n-region because ______.
In a p-n junction diode, the current I can be expressed as
I = `"I"_0 exp ("eV"/(2"k"_"BT") - 1)`
where I0 is called the reverse saturation current, V is the voltage across the diode and is positive for forward bias and negative for reverse bias, and I is the current through the diode, kBis the Boltzmann constant (8.6×10−5 eV/K) and T is the absolute temperature. If for a given diode I0 = 5 × 10−12 A and T = 300 K, then
(a) What will be the forward current at a forward voltage of 0.6 V?
(b) What will be the increase in the current if the voltage across the diode is increased to 0.7 V?
(c) What is the dynamic resistance?
(d) What will be the current if reverse bias voltage changes from 1 V to 2 V?
Explain, with the help of a circuit diagram, the working of a photo-diode. Write briefly how it is used to detect the optical signals.
When a p-type impurity is doped in a semiconductor, a large number of holes are created, This does not make the semiconductor charged. But when holes diffuse from the p-side to the n-side in a p-n junction, the n-side gets positively charged. Explain.
The drift current in a p-n junction is
The diffusion current in a p-n junction is
In a p-n junction with open ends,
(a) there is no systematic motion of charge carries
(b) holes and conduction electrons systematically go from the p-side to n-side and from the n-side to p-side respectively
(c) there is no net charge transfer between the two sides
(d) there is a constant electric field near the junction.
A semiconducting device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. the device may be
(a) an intrinsic semiconductor
(b) a p-type semiconductor
(c) an n-type semiconductor
(d) a p-n junction
Each of the resistance shown in figure has a value of 20 Ω. Find the equivalent resistance between A and B. Does it depend on whether the point A or B is at higher potential?
Find the current through the battery in each of the circuits shown in figure.
(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
Find the current through the resistance R in figure if (a) R = 12Ω (b) R = 48Ω.
(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
A load resistor of 2kΩ is connected in the collector branch of an amplifier circuit using a transistor in common-emitter mode. The current gain β = 50. The input resistance of the transistor is 0.50 kΩ. If the input current is changed by 50µA. (a) by what amount does the output voltage change, (b) by what amount does the input voltage change and (c) what is the power gain?
An AC source is connected to a diode and a resistor in series. Is the current thorough the resistor AC or DC?
Zener breakdown occurs in a p-n junction having p and n both:
How is a true p-n junction created instead of physically joining separate semiconductor pieces?
In which circuits are diodes used for signal detection?
What is the approximate knee voltage for germanium?
What is the approximate knee voltage for silicon?
Which formula gives the dynamic resistance of a diode?
