1. NOCTI Review Lesson 1 Objectives: Discuss resistor color band and determine resistor values and tolerance. Compute values using formulas for series, parallel, and series/parallel circuits.

3. Resistor Color Code The first two color bands represent number values. The third color band is called the multiplier.

4. This means to combine the first two numbers and multiply the resulting two-digit number by the power of 10 indicated by the value of the third band.

5. The forth band indicates the tolerance. For example: assume a resistor has color bands of brown, green, red, and silver.

6. The first two bands represent the numbers 1 and 5 (brown is 1 and green is 5). The third band is red, number value of 2. Multiply 15 times 100, is 1500 ohms.

7. The forth band is silver. Which is +or- 10%. 1500 X 0.10 = 150 1500 + 150 = 1650 ohms 1500 – 150 = 1350 ohms

8. A resistor has color bands of red, yellow, brown, silver. What are the resistance and tolerance of this resistor?

9. 240 ohms and 10%

10. Find the value and tolerance for blue, gray, red, and gold.

11. 6800 ohms and 5%

12. Resistor in Series, Parallel, and Series/Parallel

13. Series Circuit Rules 1. The total Voltage in a Series Circuit is equal to the sum of the individual Voltage drops. ET = E1 + E2 + E3 + etc.

14. 2. The total Current in a Series Circuit is equal to the Current flow through out the whole circuit. IT = I1 = I2 = I3 = etc.

15. 3. The total Resistance in a Series Circuit is equal to the sum of the individual resistance’s. RT = R1 + R2 + R3 + etc.

16. Parallel Circuit Rules 1.The total Voltage in a Parallel Circuit is equal to the individual voltage drops across each Parallel Branch. ET = E1 = E2 = E3 = etc.

17. 2. The total Current in a Parallel Circuit is equal to the sum of the individual Parallel branch currents. IT = I1 + I2 + I3 + etc.

18. 3.Resistance: An increase in Parallel branch results in a decrease in total Resistance. Equal Resistors: RT = R/N, R = Resistance, N = The number of equal Resistors.

19. Two Resistors of unequal value: Product/sum RT = R1 x R2 ------------ R1 + R2

20. More than two Resistors of unequal value: Reciprocal 1 ______________________ 11 1 + + ___ R1R2 R3

21. ER1 = _______ IT = ______ IR3 = _______ ER5 = _______ 100 V

22. EIR R129V.029A 1000 R253.6V.029A1848 R31.45v.029A 50 R47.25v.029A 250 R58.7v.029A 300 T100v.029A3448

23. RT = _______ IR2 = _______ IR3 = _______ R1 = _______

24. EIR R1250v 2.94A 85.03 R2 250v49.97A 5.0 R3250v 1.83A 137 T 250v54.75A 4.57

25. IR2 = __________ RT = __________

26. EIR R137V 3.08A 12 R22.96V.74A 4 R334.04V.74A 46 T37V 3.82A 9.68