# Did I pass my exam????!

Discussion in 'General Electronics Discussion' started by Karl Backe, May 28, 2015.

1. ### Karl Backe

1
0
May 28, 2015
Hi guys!

I'm so curious. I've just finished a hard exam (well, at least for me) and I will have to wait a few weeks before the offical result comes out. So I thought I ask you here, did I pass or not?

I've figured out that if I had the right answer on one of this, it means I did... so did I pick the right answer?

I'd be very pleased to know, thanks!

Question 1

Question 2

2. ### Heevy

4
0
May 27, 2015
as far as i can see, the first is a second order lowpass filter which would make it:

T(s) = 1/LC / (s^2+s(1/CR)+ 1/LC) so that would be the second choice.

As for the second problem, a voltage divider times 10/s:

10/s * 1000 / s*10*10^-3 + 1000 = 100*10^4 / s*(s+100*10^3)

as far as i can see, the first one is wrong but the second one is correct

Best of luck to you.

Heevy

3. ### Ratch

1,094
335
Mar 10, 2013
Your second answer is correct. It is a simple algebraic manipulation to find the answer. The first answer is wrong, because you can see that the curve is dropping 40 db per decade. Therefore there must be a s^2 term in the denominator when there are no s terms in the numerator. The second answer is the only one that fits that criteria.

Ratch