Title: Facilitator Help Page: Quiz 5-9 -- (Do Not Publish)
Course: Basic Electrical Theory and Wiring (Sandbox) > Section: Module 5: Resistance

Labe 5-9 Quiz Answers

1. \(R_{Tot}=\frac{1}{\frac{1}{680+270}+\frac{1}{430}}+1000=\frac{1}{\frac{1}{950}+\frac{1}{430}}+1000=\frac{1}{0.002326+0.001053}+1000=\frac{1}{0.003378}+1000=296.0145\:+\:1000\:=\:1296Ω\)
  1. The student should measure between 1231 and 1360 Ω.
2. \(R_{Tot}=\frac{1}{\frac{1}{240+270+470}+\frac{1}{390}}+1000+1000=\frac{1}{\frac{1}{980}+\frac{1}{390}}+2000=\frac{1}{0.002564+0.00102}+2000=\frac{1}{0.003585}+2000=278.98\:+\:2000\:=\:2279Ω\:=\:2.279\:kΩ\)
  1. The student should measure between 2.165 and 2.393 kΩ
3. Done in 2 parts.
  1. \(R_{P1}=\frac{1}{\frac{1}{390}+\frac{1}{270}}+270=\frac{1}{0.002564+0.003704}+270=\frac{1}{0.006268}+270=429.54Ω\)
  2. \(R_{Tot}=\frac{\:1}{\frac{1}{R_{P1}}+\frac{1}{270}}=\frac{\:1}{\frac{1}{429.54}+\frac{1}{270}}=\frac{1}{0.002328+0.003704}=\frac{1}{0.006032}=166\:Ω\)
    1. The student should measure between 158 and 143 .
4. Done in 4 parts
  1. \(R_{P1}=\frac{1}{\frac{1}{680+270}+\frac{1}{270}}=\frac{1}{\frac{1}{950}+\frac{1}{270}}=\frac{1}{0.001053+0.003704}=210.2459\:Ω\)
  2. \(R_{P2}=\frac{1}{\frac{1}{R_{P1}+430}+\frac{1}{270}}=\frac{1}{\frac{1}{210.2459+430}+\frac{1}{270}}=\frac{1}{\frac{1}{640.2459}+\frac{1}{270}}=\frac{1}{0.001562+0.003704}=189.9118\:Ω\)
  3. \(R_{P3}=\frac{1}{\frac{1}{R_{P2}+390}+\frac{1}{270}}=\frac{1}{\frac{1}{189.9118+390}+\frac{1}{270}}=\frac{1}{\frac{1}{579.9118}+\frac{1}{270}}=\frac{1}{0.001724+0.003704}=184.2264\:Ω\)
  4. \(R_{Tot}=240\:+\:R_{P3}=240+184.2264\:=\:424\:Ω\)
    1. The student should measure between 403 and 445 Ω.
5. There will be differences. Most often the measured value is lower. Also, each resistor has a tolerance. Most of ours are + or - 5%.

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