Advertisements
Advertisements
Question
Find the equivalent resistance of the network shown in figure between the points A and B.
(Assume that the resistance of each diode is zero in forward bias and is infinity in reverse bias.)
Advertisements
Solution
Let the potentials at A and B be VA and VB, respectively.
(i) When VA > VB, that is, a battery is connected between points A and B, with its positive terminal connected to point A and its negative terminal connected to point B:
As the potential on the p-side of the diode is greater than the potential on the n-side of the diode, the diode is forward biased; thus, it can be replaced by a short circuit.
As the two resistances are connected in parallel, the effective resistance becomes
Equivalent resistance \[= \frac{10}{2} = 5 \Omega\]
(ii) When VA < VB:
The diode is reverse biased, so it is replaced by an open circuit. Thus, no current flows through this branch.
∴ Equivalent resistance = 10 Ω
APPEARS IN
RELATED QUESTIONS
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?
Write the two processes that take place in the formation of a p-n junction.
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?
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.
Diffusion current in a p-n junction is greater than the drift current in magnitude
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?
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?
An AC source is connected to a diode and a resistor in series. Is the current thorough the resistor AC or DC?
A diode, a resistor and a 50 Hz AC source are connected in series. The number of current pulses per second through the resistor is __________ .
Choose the correct option.
Current through a reverse-biased p-n junction increases abruptly at:
p-n junction diode is formed
The formation of the depletion region in a p-n junction diode is due to ______.
For an ideal diode, in forward and reverse biased condition the resistance is respectively ______.
Diode and resistance are connected as shown in figure. Out of the following statements which one is TRUE?
In p-n junction diode ______.
