Current Amplification Ratio

[TehBigBoss]

Homework Statement

If I_B and I_C (I_B = Base current and I_C = Collector current) of bipolar junction transistor are 1mA and 100 mA respectively, determine its current amplification ratio in common emitter configuration.

Homework Equations

I_C=β*I_B
Where β = current gain = $\alpha$/($\alpha$-1) (is this the same as current amplification ratio)?

Where $\alpha$ = I_C/I_E (I_E = Emitter current)

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 = I_C/I_B = 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.

 

[NascentOxygen]

100 is right. Too easy?

 

[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!

 

[NascentOxygen]

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!

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

 

[HalfLostAndSearching]

Your solution is correct! The current amplification ratio, also known as the current gain, is simply the ratio of collector current to base current. In this case, the current amplification ratio is 100, which means that for every 1 mA of base current, there will be 100 mA of collector current. This is a fundamental property of bipolar junction transistors and is often used in circuit design. Great job!