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ECE 252 Introduction to Electrical Engineering
Lesson 2. Resistors in Series and Parallel Homework
Version S17
Homework partner name: _______________________Homework partner name: ________________________
Please note: You don’t need delta-wye transformation for this assignment.
1. Quickies
a) Engineers define current as the flow of ( electrons, protons, negative charges, positive charges ).
b) Some of the resistors in the circuit below ( are in parallel, are in series, are neither in series nor in parallel ).
Signatures: ________________________________________________________________________
2. R1 = 9 Ω, R2 = 24 Ω, R3 = 12 Ω, R4 = 5 Ω. Find the resistance between X and Y. The answer is an integer.
RXY =
Signatures: ________________________________________________________________________
3. R1 = 38 Ω, R2 = 22 Ω, R3 = 15 Ω, R4 = 12 Ω. Find the resistance between C and D. The answer is an integer.
RCD =
Signatures: ________________________________________________________________________
4. R1 = 84 Ω, R2 = 160 Ω, R3 = 240 Ω, R4 = 90 Ω. Find the resistance between E and F. The answer is an
integer.
REF =
Signatures: ________________________________________________________________________
5. R1 = 15 Ω, R2 = 4 Ω, R3 = 60 Ω, R4 = 14 Ω, R5 = 20 Ω, R6 = 30 Ω, R7 = 25 Ω, R8 = 75 Ω. Find the resistance
between A and B. The answer is an integer.
RAB =
Signatures: ________________________________________________________________________
6. a) Using exactly five 24 Ω resistors and no other resistors, design and sketch a circuit with a resistance of
exactly 28 Ω. All five resistors must be significant parts of the circuit. b) Combine resistors in series and parallel
to prove that your circuit has the correct resistance. Note: Don’t spend more than ½ hour on this problem.
Signatures: ________________________________________________________________________
7. E is 40 V. R1 is 100 kΩ and has a tolerance of 20%. R2 is 50 kΩ and has a tolerance of 10%. What is the
maximum possible voltage for Vout? What is the minimum possible voltage for Vout?
Max Vout =
Min Vout =
Signatures: ________________________________________________________________________
8. E = 18V. R1 = 9 MΩ. R2 = 1 MΩ. A student uses a voltage divider in hopes of converting 18 V to 2 V, using the
circuit shown. When the student connects a cheap volt-ohm meter (VOM) to Vout, she gets just 1.75 V. Explain
why the voltage is lower than expected. Note: This problem has nothing to do with tolerance (the resistor values
are correct), or temperature. Furthermore, the VOM does not have an accuracy problem.
Signatures: ________________________________________________________________________
BONUS (no partial credit). What is the color code for a 91 kΩ resistor with a tolerance of 5% and 4 color bands?
Signatures: ________________________________________________________________________