my instructor told me to find out the reason of the following fact:

why the power dissipation in transistor decreases with increase in collector current after a certain value.he also said that the power dissipation also decreases before that certain value of collector current.

it seems to me mysterious cause power dissipation means only voltage drop multiplied by current through.can u explain the reason,plz?

 

Take a look at what happens to the voltage drop between the collector and the emitter when the collector current increase significantly and then apply your understanding of the definition of power dissipation.

That should reveal the answer to you.

hgmjr