Solving Numericals from Previous Year Questions (PYQ) | GATE Electronic Devices - Part 31

TL;DR

A video discusses a Gate question on a NPN Bipolar Junction Transistor and explains how to calculate the collector current.

Transcript

hello friends in this video we are going to discuss about a previous year gate question on electronics device according to the numerical given we can see that a bipolar Junction transistor has been given in the question and it is a NPN transistor where the excess electron profile has been given and it is said that a BJT is biased in a active region... Read More

Key Insights

• ☢️ The Gate question involves analyzing a NPN Bipolar Junction Transistor operating in the active region.
• ⚾ The emitter-base Junction is forward biased, while the base-collector Junction is reverse biased.
• ❓ The diffusion current dominates the total current in the BJT.
• ❓ The Einstein equation is used to calculate the diffusion coefficient.
• 💱 The given electron profile helps determine the change in excess electron concentration within a specific distance.
• 🎮 The video provides the necessary values to calculate the collector current.
• ❓ The collector current is found to be 6.656 milliamperes.

Questions & Answers

Q: What is the given configuration of the Bipolar Junction Transistor in the Gate question?

The Bipolar Junction Transistor in the question is a NPN transistor biased in the active region, with the emitter-base Junction in forward bias and the base-collector Junction in reverse bias.

Q: How is the collector current (IC) calculated in the video?

To calculate IC, the video derives it using the diffusion current dominated behavior of the BJT and applies the formula IC = A * Q * μn * VT * (DN/DX). The necessary values for A, Q, μn, VT, DN, and DX are provided, leading to a value of 6.656 milliamperes.

Q: What is the significance of the given electron profile in the question?

The given electron profile represents the excess electron concentration, which is changing from 10^14 to 0 within a specified distance. This information is crucial for calculating DN (the diffusion coefficient for electrons) and ultimately finding IC.

Q: What is the Einstein equation mentioned in the video?

The Einstein equation relates the diffusion coefficient (DN) of a particle (in this case, electrons) to its mobility (μ). It is given by DN = μ * VT, where VT is the thermal voltage or thermal voltage equivalent to k * T / q.

Summary & Key Takeaways

• The video analyzes a Gate question on a NPN Bipolar Junction Transistor biased in the active region.

• The emitter-base Junction area and electron mobility values are given.

• By applying the Einstein equation and diffusion phenomena, the video calculates the value of the collector current.