Bissoy.com
Doctors Medicines MCQs Q&A

What accounts for the flow of charge carriers in forward and reverse biasing of silicon p-n diode -

What accounts for the flow of charge carriers in forward and reverse biasing of silicon p-n diode - Correct Answer Drift in reverse bias and diffusion in forward bias

Concept:

  • In a p-n junction, forward-biased majority charge carriers cross the junction to become minority carriers i.e. Minority carries injection takes place.
  • Because of the huge concentration gradient at the edge of the junction of minority carriers, diffusion takes place which results in the flow of current across the junction.

 

A diode in forward-bias is as shown:

[ alt="F1 S.B Pallavi 09.11.2019 D 6" src="//storage.googleapis.com/tb-img/production/19/11/F1_S.B_Pallavi_09.11.2019_D%206.png" style="width: 288px; height: 204px;">

  • When Reverse-biased, the flow of the majority varies is prevented because of a wide depletion region and high electric field opposing the flow. So, there is no diffusion current that could flow.
  • The reverse bias opposes the majority carriers but makes the minority carriers to cross the p-n junction because of strong attraction by the Electric field.

 

The depletion width is clearly observed for a reverse-biased p-n junction as:

[ alt="F1 S.B Pallavi 09.11.2019 D 7" src="//storage.googleapis.com/tb-img/production/19/11/F1_S.B_Pallavi_09.11.2019_D%207.png" style="width: 307px; height: 193px;">

Related Questions

What accounts for the flow of charge carriers in forward and reverse biasing of silicon p-n diode?
The question given below consists of a statement, followed by three arguments I, II and III. You have to decide which of the arguments is/are ‘strong’ arguments is/are ‘weak’ arguments and accordingly choose your answer from the alternatives given below each question. Statement: For users, Facebook's revelation of a data breach that gave attackers access to 50 million accounts raises an important question: What happens next? For the owners of the affected accounts, and of another 40 million that Facebook considered at risk, the first order of business may be a simple one: sign back into the app. Facebook logged everyone out of all 90 million accounts in order to reset digital keys the hackers had stolen - keys normally used to keep users logged in, but which could also give outsiders full control of the compromised accounts.  Which of the following points do not capture the negligence of Facebook in the most appropriate manner? Arguments: I. What Facebook knows so far is that hackers got access to the 50 million accounts by exploiting three distinct bugs in Facebook's code that allowed them to steal those digital keys, technically known as ‘access tokens’. The company says it has fixed the bugs.  II. The hack is the latest setback for Facebook during a tumultuous year of security problems and privacy issues . So far, though, none of these issues have significantly shaken the confidence of the company's 2 billion global users.  III. One of the bugs was more than a year old and affected how the ‘View As’ feature interacted with Facebook's video uploading feature for posting ‘happy birthday’ messages. But it wasn't until mid-September that Facebook noticed an uptick in unusual activity, and not until this week that it learned of the attack.
Silicon devices can be employed for a higher temperature limit (190°C to 200°C) as compared to germanium devices (85°C to 100°C). With respect to this, which of the following are incorrect? 1) Higher resistivity of silicon 2) Higher gap energy of silicon 3) Lower intrinsic concentration of silicon 4) Use of silicon devices in high-power applications Select the correct answer using the code given below:
Which of the following are true? 1) In reverse bias, the diode undergoes stages of storage and transition times 2) Minority charge carriers accumulation makes the diode as a short circuit 3) Storage time is the sum of recovery and transition times
Advantage of Schottky diode over silicon crystal diode is the presence minority charge carriers.
Consider the following statements: 1. In a silicon controlled rectifier (SCR), if the cathode gate is reverse-biased, then the SCR cannot fire at all. 2. The turn-on time of an SCR increases with temperature. 3. After an SCR is turned on, it can be made to turn off again by reverse biasing the gate. 4. Gate recovery time is the minimum time that the anode voltage must be maintained below holding voltage VH to turn off the SCR. Which of these statements are correct?
The input voltage V1 of the circuit the circuit is 2V and resistor has a resistance of 1KΩ. The cut-in voltage of the silicon diode is 0.7V and the reverse saturation current is 10-8A. The temperature at which diode operates is 30°C. The voltage across resistor when diode starts conducting is _________________
The output of the following Python code is similar to the alphabet . . . . . . . .
import turtlet=turtle.Pen()t1=turtle.Pen()t2=turtle.Pen()t.forward(100)t1.forward(100)t2.forward(100)t1.left(90)t1.forward(75)t2.right(90)t2.forward(75)
From the given circuit diagram, considering the diode to be a silicon semiconductor diode, what is the magnitude of diode current? (Use an appropriate model of the diode)
Find the current Ix if the voltage across the diode is 0.5V. The reverse saturation current of diode 10-11A, the cut-in voltage of diode is 0.6V. Assume that the temperature at which diode operates is 25°C. The resistance R1=2KΩ.