- #1
freswood
- 11
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My year 12 exams are in 1 week exactly and I'm worried about a question (from last year's exam) that my teacher can't even answer. Each year they tend to repeat the difficult questions, and this was one of those.
I'll just give a summary of the question, and maybe you'll be able to answer my question without having to look at it.
- An AC input signal of 0.3V peak to peak is applied at the base.
- There is also a DC voltage of 4 V going through the base.
- The voltage gain is 200.
- The DC supply voltage is 20 V.
- They don't give a linear transfer characteristic.
To answer the question, you have to draw a graph of output voltage against time. In their answer, the graph is clipped at +8 and -12. I don't understand where they got those values from. What I thought I had to do was add the AC voltage to the DC across the base (ie. sinusoidal from 3.85 to 4.15, varying about 4V) and then normally you just read off the V in against V out graph.
The question is in this pdf: http://www.vcaa.vic.edu.au/vce/studies/physics/pastexams/2006/physics1w06.pdf
It's in the electronics section, question 3.
This post is so messy - hopefully you'll be able to understand it. I so desperately need the answer to this! Thanks for your help
I'll just give a summary of the question, and maybe you'll be able to answer my question without having to look at it.
- An AC input signal of 0.3V peak to peak is applied at the base.
- There is also a DC voltage of 4 V going through the base.
- The voltage gain is 200.
- The DC supply voltage is 20 V.
- They don't give a linear transfer characteristic.
To answer the question, you have to draw a graph of output voltage against time. In their answer, the graph is clipped at +8 and -12. I don't understand where they got those values from. What I thought I had to do was add the AC voltage to the DC across the base (ie. sinusoidal from 3.85 to 4.15, varying about 4V) and then normally you just read off the V in against V out graph.
The question is in this pdf: http://www.vcaa.vic.edu.au/vce/studies/physics/pastexams/2006/physics1w06.pdf
It's in the electronics section, question 3.
This post is so messy - hopefully you'll be able to understand it. I so desperately need the answer to this! Thanks for your help