ECE 1250 Final Part 1-- Replaces Midterm I
April 30, 2015
Name___________________________________________________
Homework Folder # _________
You may use your notes and a calculator but no textbook. Read each problem carefully.
Good luck, and do well!
Part I – Replaces Midterm I
Problem 1
Problem 2
Problem 3
____ / 40 points
____ / 40 points
____ / 20 points
Total Part 1
____ / 100 points
SHOW YOUR WORK to receive full credit
1. (40 points) For Vs = 1V, R1=R2=R3=R4= 1kΩ, Find I1.
SHOW YOUR WORK to receive full credit
2. (40 points) Use voltage and/or current dividers to find:
a) Va = ________ volts (calculate the value)
b) I2 = ________amps
(calculate the value)
SHOW YOUR WORK to receive full credit
3. (20 points) If all resistors = 1kΩ, find Rin = _______ kΩ
SHOW YOUR WORK to receive full credit
ECE 1250 Final Part 2-- Replaces Midterm II
April 30, 2015
Name___________________________________________________
Homework Folder # _________
You may use your notes and a calculator but no textbook. Read each problem carefully.
Good luck, and do well!
Part 2 – Replaces Midterm II
Problem 1
Problem 2
____ / 50 points
____ / 50 points
Total Part 2
____ / 100 points
SHOW YOUR WORK to receive full credit
1.(50 points) Given Vs=10V, R1=R2=R3=1kΩ. Find Va = ________
SHOW YOUR WORK to receive full credit
2. (50 points) Note: this circuit is the same as problem 1, and you may re-use your
calculations for Va. Find the Thevenin equivalent circuit:
SHOW YOUR WORK to receive full credit
ECE 1250 Final Part 3-- Replaces Midterm III
April 30, 2015
Name___________________________________________________
Homework Folder # _________
You may use your notes and a calculator but no textbook. Read each problem carefully.
Good luck, and do well!
Part 3 – Replaces Midterm III
Problem 4
Problem 5
Problem 6
____ / 30 points
____ / 30 points
____ / 40 points
Total Part 3
____ / 100 points
1.
SHOW YOUR WORK to receive full credit
(30 points) (Hint: This system is made up of ‘standard’ op amp circuits such as
summers, amplifiers, voltage followers, etc.)
Given V1 = 10V. R1=R2=R3=R4= 1kΩ
(a) Circle and Label the types of standard op amp circuits in this system.
(b) Find V2 = _____________
(c) Find V3 = _____________
(d) Find Vout = ___________
NOTE: If you get stuck and can’t find V2 or V3 or Vout, just use the one(s) you
can’t find as variables and proceed to compute the remaining voltages as a
function of those variables.
SHOW YOUR WORK to receive full credit
2. (30 points) Given V1 = V2=10V and all resistors = 1kΩ. Find Vout.
Hint 1: One good way to do this is to assume the op amp is ideal and use the nodevoltage method.
Hint 2: Does any current travel through R2? R3?
SHOW YOUR WORK.
SHOW YOUR WORK to receive full credit
3.
(40 points) Design a system that uses op amps to:
 Calculate Vout = 3 V1 + 0.5 V2 – 7 V3.
 Use any combination of voltage and current dividers, inverting and noninverting amplifiers and summers, differencing (subtracting) amplifiers, op
amp switches, voltage followers, etc.
a) Draw the BLOCK DIAGRAM of your system, and EXPLAIN how it works.
(There are many ways to design this system, please help me understand yours.)
b) Draw the CIRCUIT DIAGRAM (the op amps, resistors, etc.)
c) Specify the values of all resistors, etc. for your design.
SHOW YOUR WORK to receive full credit
ECE 1250 Final Part 4-- Replaces Midterm IV
April 30, 2015
Name___________________________________________________
Homework Folder # _________
You may use your notes and a calculator but no textbook. Read each problem carefully.
Good luck, and do well!
Part 4 – Replaces Midterm IV
Problem 7
Problem 8
Problem 9
____ / 20 points
____ / 40 points
____ / 40 points
Total Part 4
____ / 100 points
1.
SHOW YOUR WORK to receive full credit
(20 points) For a parallel plate capacitor, how will the following affect the total
capacitance? (Circle your answers)
a) Increasing the size of both plates
WILL
Increase Decrease NoChange
b) Increasing the size of ONE plate?
WILL
Increase Decrease NoChange
c) Adding pure (deionized) water between the plates?
WILL Increase Decrease NoChange
d) Increasing the distance between the plates?
WILL
Increase Decrease NoChange
e) Increasing the voltage across the plates?
WILL
Increase Decrease NoChange
SHOW YOUR WORK to receive full credit
2. (40 points) What should L1 be so Zin = 1kΩ?
SHOW YOUR WORK to receive full credit
3. (40 points) Write an expression for Va.
SHOW YOUR WORK to receive full credit