Current Amplification Ratio

1. Mar 2, 2014

TehBigBoss

1. The problem statement, all variables and given/known data
If IB and IC (IB = Base current and IC = Collector current) of bipolar junction transistor are 1mA and 100 mA respectively, determine its current amplification ratio in common emitter configuration.

2. Relevant equations
IC=β*IB
Where β = current gain = $\alpha$/($\alpha$-1) (is this the same as current amplification ratio)???

Where $\alpha$ = IC/IE (IE = Emitter current)

3. The attempt at a solution
I understand that whatever signal is input in through the base is amplified out through the collector.

I found this page very helpful http://230nsc1.phy-astr.gsu.edu/hbase/solids/trans2.html#c6

β = IC/IB = 100mA/10mA = 100

Was this problem really that easy?! Or am I missing something big here? Professor usually assigns pretty involved homework problems.

Thank you.

2. Mar 2, 2014

Staff: Mentor

100 is right. Too easy?

3. Mar 2, 2014

TehBigBoss

Well he usually give us problems where we have to derive our own equations to use. This one seemed too much like a plug and chug question considering that equation was all over the lecture and book. Thank you though!

4. Mar 2, 2014

Staff: Mentor

The solution would have been slightly more challenging had you been told that it was the emitter current that was 100mA, determine β.

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