Complete Electronics Self-Teaching Guide with Projects

DC Pre-Test

The following problems and questions test your understanding of the basic principles presented in this chapter. You need a separate sheet of paper for your calculations. Compare your answers with the answers provided following the test. You can work many of the problems in more than one way.

Questions 1–5 use the circuit shown in Figure 1.20. Find the unknown values indicated using the values given.

Figure 1.20

1. R₁ = 12 ohms, R₂ = 36 ohms, V_S = 24 volts

R_T = _____ , I = _____

2. R₁ = 1 kΩ, R₂ = 3 kΩ, I = 5 mA

V₁ = _____ , V₂ = _____ , V_S = _____

3. R₁ = 12 kΩ, R₂ = 8 kΩ, V_S = 24 volts

V₁ = _____ , V₂ = _____

4. V_S = 36 V, I = 250 mA, V₁ = 6 volts

R₂ = _____

5. Now, go back to problem 1. Find the power dissipated by each resistor and the total power delivered by the source.

P₁ = _____ , P₂ = _____ , P_T = _____

Questions 6–8 use the circuit shown in Figure 1.21. Again, find the unknowns using the given values.

Figure 1.21

6. R₁ = 6 kΩ, R₂ = 12 kΩ, V_S = 20 volts

R_T = _____ , I = _____

7. I = 2 A, R₁ = 10 ohms, R₂ = 30 ohms

I₁ = _____ , I₂ = _____

8. V_S = 12 volts, I = 300 mA, R₁ = 50 ohms

R₂ = _____ , P₁ = _____

9. What is the maximum current that a 220- ohm resistor can safely have if its power rating is 1/4 watt?

I_MAX = _____

10. In a series RC circuit ...