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### Course: Modern Physics (Essentials) - Class 12th>Unit 5

Lesson 4: How current flows in transistors

# Transistor current and parameters

Let's explore the names of the currents through the transistor, find the connection between them and talk about transistor parameters. These parameters tell us how good or bad a transistor is. Created by Mahesh Shenoy.

## Want to join the conversation?

• Why is Ic the output current? Isn't it coming back into the transistor?
• Ic is the output current as it is the amplified version of Ib which is required by the stereo to convert it into sound wave.
• Won't some electrons go to the ground and therefore emiiteer current will be less than sum of collector and base currrent?
• As we know that the current (flow of charges) always flows from lower potential to higher potential,but here the potential of ground and that of emitter wire is same,hence no current would flow and therefore no transfer of charge to the ground.
• How did he get the equation for beta?
(1 vote)
• Beta is IC / IB (Found by rearranging the current gain formula). Beta is a ratio between IC and IB, so the Ie gets cancelled out. We know that IC = alpha, so IB is the rest of the total, which is 1 - alpha. Therefore Beta = alpha / (1 - alpha).
• why is the Ic the output current when both are coming inside at 5.47
(1 vote)
• Ic is the output current as it is the amplified version of Ib which is required by the stereo to convert it into sound wave.
• can you compare the terms Ib, Ic and Ie to terms like Ig, Id, Is? in my electrical Engineering class we use the terms IG- Gate current ID -Current Drain and IG- which is I ground, i'm just having trouble with term association.
(1 vote)
• IG- gate current is IB in the video
ID - drain current is the IC collector current
IS - source current is the IE in the video