(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

2. Relevant equations

For the 1st part

Ohms law and resistance across zener is 10V

I cant get 2nd

3. The attempt at a solution

For 1st part I took Vi/p = 18V

Putting KVL for left loop of source-->collector-->base-->zener-->ground

18 = Vcb + 10

So Vcb = 8V

And Vbe = 0.7V

So Vce = 8.7V Correct answer.

For second question,

P dissipated in transistor = Vce times total current = Vce times Ie

Ie = 10 - 0.7 divided by 1 K

=9.3mA

So P dissipated by transistor = 8.7 times 9.3 = 80.91 mW

Book answer is A.

Where am I wrong?

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# Homework Help: Power dissipated across a transistor regulator

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