Advertisements
Advertisements
प्रश्न
Find the currents through the resistance in the circuits shown in figure.
(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
Advertisements
उत्तर
We know that under forward bias, an ideal diode acts as a short circuit; and under reverse bias, an ideal diode acts as an open circuit.
(a) Since both the diodes are forward biassed, they can be replaced by short circuits.
Net resistance = 2 Ω
\[i = \frac{2 V}{2 \Omega} = 1 A\]
(b) One diode is forward biassed and the other is reverse biassed; thus, the resistance of one becomes ∞. The circuit becomes open at the position of the second diode, so no current flows through this arm.
\[\therefore i = \frac{2}{2 + \infty} = 0 A\]
(c) Both of them are forward biassed. Thus, the resistance is zero.
We can replace both the resistors by short circuits.
Net resistance = 2 Ω
\[\therefore i = \frac{2}{2} = 1 A\]
(d) One of them is forward biassed and the other is reverse biassed.
Thus, the current passes through the forward-biassed diode and the other acts as open circuit.
\[\therefore i = \frac{2}{2} = 1 A\]
APPEARS IN
संबंधित प्रश्न
In an unbiased p-n junction, holes diffuse from the p-region to n-region because ______.
Explain briefly with the help of necessary diagrams, the forward biasing of a p-n junction diode. Also draw characteristic curves.
Explain briefly with the help of necessary diagrams, the reverse biasing of a p-n junction diode. Also draw characteristic curves.
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.
Mention the important considerations required while fabricating a p-n junction diode to be used as a Light Emitting Diode (LED). What should be the order of band gap of an LED if it is required to emit light in the visible range?
Explain, with the help of a circuit diagram, the working of n-p-n transistor as a common emitter amplifier.
How is a zener diode fabricated so as to make it a special purpose diode? Draw I-V characteristics of zener diode and explain the significance of breakdown voltage.
Explain briefly, with the help of a circuit diagram, how a p-n junction diode works as a half wave rectifier.
If the two ends of a p-n junction are joined by a wire,
The diffusion current in a p-n junction is
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
The potential barrier existing across an unbiased p-n junction is 0.2 volt. What minimum kinetic energy a hole should have to diffuse from the p-side to the n-side if (a) the junction is unbiased, (b) the junction is forward-biased at 0.1 volt and (c) the junction is reverse-biased at 0.1 volt?
The drift current in a p-n junction is 20.0 µA. Estimate the number of electrons crossing a cross section per second in the depletion region.
The current−voltage characteristic of an ideal p-n junction diode is given by \[i = i_0 ( e^{eV/KT} - 1)\] where, the drift current i0 equals 10 µA. Take the temperature T to be 300 K. (a) Find the voltage V0 for which \[e^{eV/kT} = 100 .\]One can neglect the term 1 for voltages greater than this value. (b) Find an expression for the dynamic resistance of the diode as a function of V for V > V0. (c) Find the voltage for which the dynamic resistance is 0.2 Ω.
(Use Planck constant h = 4.14 × 10-15 eV-s, Boltzmann constant k = 8·62 × 10-5 eV/K.)
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?
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.)
Choose the correct option.
Current through a reverse-biased p-n junction increases abruptly at:
If in a p-n junction diode, a square input signal of 10 V is applied as shown Then the output signal across RL will be ______
During the formation of a p-n junction ______.
