ECE 202 – Fall 2013

Exam #1

September 19, 2012

Circle your division:

Division 0101: Furgason (8:30 am)

Division 0201: Bermel (9:30 am)

Name (Last, First)______________________________

Purdue ID #_____________________________

There are 10 multiple choice problems (7 points each),

and 2 workout problems (15 points each).

Instructions

1. DO NOT START UNTIL TOLD TO DO SO.

2. Write your name, division, professor, and student ID# on your scantron sheet and this packet.

3. This is a CLOSED BOOKS and CLOSED NOTES exam.

4. Calculators are not allowed.

5. If extra paper is needed, use back of test pages.

6. Cheating will not be tolerated. Cheating in this exam will result in an F in the course.

7. If you cannot solve a question, be sure to look at the other ones and come back to it if time permits.

8. As described in the course syllabus, we must certify that every student who receives a passing grade in this

course has satisfied each of the course outcomes. On this exam, you have the opportunity to satisfy outcomes i,

ii, and iii. (See the course syllabus for a complete description of each outcome.) On the chart below, we list the

criteria we use for determining whether you have satisfied these course outcomes.

Course

Outcome

Exam

Questions

Total Questions Minimum #

correct responses

required to satisfy

course outcome

i 4,5,11 3 2

ii 1-3,8 4 2

iii 6,7,9,10,12 5 3

If you fail to satisfy any of the course outcomes, don’t panic. There will be more opportunities for you to do so.

9. You will find Laplace transforms on the final pages of this exam. You can tear them out if needed.

Multiple Choice Problems (7 points each)

1. What is the Laplace transform of = 10 − 2 + 5 cos2 − 2 − 1?

(1)

(2)

+ 5 (3)

+ (4) + 5

(5) +

(6)

+ (7) +

(8) None of these

2. What is the Laplace transform ! of the waveform shown below?

(1) −

(2)

−

+

" (3) −

(4) +

"

(5) −

+

" (6) −

+

" (7)

1 − + " (8) None of these

3. What is the inverse Laplace transform of #$%&! = '((?

(1) 7& + 13 (2) +2& − 2(&, (3) +2& + 3& − 2(&,

(4) 2& + (& (5) +7& + 13(&,− (6) +7 − 1 + 13 − 3,

(7) 7& ∙ (8) None of these

4. What is the equivalent impedance Zeq of this circuit in the Laplace domain (in Ω)?

(1) 4 + / + 2! (2) 4 + 0.125! +

(3) 4 + 8! + (4) 6.125

(5) 4 (6) 4 + /3 + 2! (7)

/ + 2! (8) None of these

5. What is the Thevenin equivalent impedance Zth for this circuit (in Ω)?

(1) 2 (2) 2 + " + 2! (3) 2 +

"+ (4) 2 + "

+ 3!

(5) 2! + 4/! (6) 2 + 2! + " (7)

+

" +

5 (8) None of these

6. Determine the transfer function 6+7!, = 89:;&8<=&

of the circuit shown below.

(1) 2( ) ( )tt e u t

−− (2) 2( ) ( )t

t e u t−

− − (3) 2( 2 ) ( )te u t

−− (4) 2( 2 ) ( )t

e u t−

− −

(5) 4(1 ) ( )te u t

−− (6) 4(1 ) ( )t

e u t−

− − (7) −2& (8) None of these

7. The step response of a certain system is given by: ( )24 2 ( )te u t

−− .

Determine the impulse response h(t).

(1) 4( 2 – e-2t

) δ(t) (2) 4( 2 + 2e-2t

) δ(t) (3) 4[δ(t) + 2e-2t

u(t) ]

(4) -4e-2t

u(t) (5) 4( 1 + 2e-2t

) u(t) (6) 8e-2t

u(t)

(7) 2( 1 + 2e-2t

) u(t) (8) None of these

8. The zero-input-response of the circuit shown below is Vout(t) = 3 e-t u(t) V.

The initial capacitor voltage, VC (0-), must have been? (in volts)

(1) -2 (2) 2 (3) 3 (4) -4

(5) 4 (6) -8 (7) 8 (8) None of these

9. A transfer function )(

)()(

sd

snKsH = has the pole-zero plot shown below, K = 4.

Determine the magnitude of the transfer function, |H(0)|.

(1) 2

2 (2) 1.5 (3) 2 (4) 2.5

(5) 3 (6) 4 (7) 4.5 (8) None of these

10. The circuit below will be stable provided that:

(1) 0α > (2) 0α < (3) Rα > (4) Rα <

(5) Rα > − (6) Rα < − (7) R Cα > (8) None of these

Workout Problems (15 points each)

11. Consider the circuit below.

What is the equivalent impedance Zeq of the resistor and inductor in series?_________________________

If = 36 36 4 and >?0 0, find the inductor current @?! in the Laplace domain.

____________________________________________________________

Finally, find the inductor current >? in the time domain. _____________________________________

12.

The circuit shown above is a bandpass filter.

Determine the transfer function, out

in

V( )

VH s = , for this filter.

H(s) = ________________________________________________________