|
Alternating Current and Transformer Lessons Alternating Current and Transformer Lessons on CD Alternating current is current which constantly changes in amplitude, and which reverses direction at regular intervals. You should already know that direct current flows only in one direction, and that the amplitude of current is determined by the number of electrons flowing past a point in a circuit in one second. If, for example, a coulomb of electrons moves past a point in a wire in one second and all of the electrons are moving in the same direction, the amplitude of direct current in the wire is one ampere. Similarly, if half a coulomb of electrons moves in one direction past a point in the wire in half a second, then reverses direction and moves past the same point in the opposite direction during the next half-second, a total of one coulomb of electrons passes the point in one second. The amplitude of the alternating current is one ampere. Works with Windows, Mac, Unix, Linux and others. Alternating Current and Transformer Lessons CONCEPTS OF ALTERNATING CURRENT Upon completion of this chapter you will be able to: 1. State the differences between ac and dc voltage and current. 2. State the advantages of ac power transmission over dc power transmission. 3. State the "left-hand rule" for a conductor. 5. State the methods by which ac power can be generated. 7. Compute peak-to-peak, instantaneous, effective, and average values of voltage and current. 8. Compute the phase difference between sine waves. Upon completion of this chapter you will be able to: 1. Write the basic unit of and the symbol for inductance. 2. State the type of moving field used to generate an emf in a conductor. 3. Define the term "inductance." 6. State the effect that inductance has on steady direct current, and direct current that is changing 7. List five factors that affect the inductance of a coil, and state how various physical changes in these factors affect inductance. 8. State the principles and sequences involved in the buildup and decay of current in an LR series 9. Write the formula for computing one time constant in an LR series circuit. 10. Solve L/R time constant problems. 11. State the three types of power loss in an inductor. 12. Define the term "mutual inductance." 13. State the meaning of the term "coupled circuits." 14. State the meaning of the term "coefficient of coupling." 15. Given the inductance values of and the coefficient of coupling between two series-connected inductors, solve for mutual inductance, M. 16. Write the formula for the "total inductance" of two inductors connected in series-opposing. 17. Given the inductance values of and the mutual inductance value between two coils connected in series-aiding, solve for their combined inductance, LT. Upon completion of this chapter you will be able to: 2. State four characteristics of electrostatic lines of force. 3. State the effect that an electrostatic field has on a charged particle. 4. State the basic parts of a capacitor. 7. State three factors that affect the value of capacitance. 8. Given the dielectric constant and the area of and the distance between the plates of a capacitor, 9. State two types of power losses associated with capacitors. 10. Define the term "working voltage" of a capacitor, and compute the working voltage of a capacitor. 11. State what happens to the electrons in a capacitor when the capacitor is charging and when it is 14. Given the component values of an RC circuit, compute the RC time constant. 15. Use the universal time constant chart to determine the value of an unknown capacitor in an RC 16. Calculate the value of total capacitance in a circuit containing capacitors of known value in series. 17. Calculate the value of total capacitance in a circuit containing capacitors of known value in 18. State the difference between different types of capacitors. 19. Determine the electrical values of capacitors using the color code. INDUCTIVE AND CAPACITIVE REACTANCE Upon completion of this chapter you will be able to: 1. State the effects an inductor has on a change in current and a capacitor has on a change in voltage. 4. Write the formulas for inductive and capacitive reactances. 5. State the effects of a change in frequency on X L and XC. 6. State the effects of a change in inductance on X L and a change in capacitance on XC. 7. Write the formula for determining total reactance (X); compute total reactance (X) in a series circuit; and indicate whether the total reactance is capacitive or inductive. 8. State the term given to the total opposition (Z) in an ac circuit. 9. Write the formula for impedance, and calculate the impedance in a series circuit when the values 10. Write the Ohm's law formulas used to determine voltage and current in an ac circuit. 11. Define true power, reactive power, and apparent power; state the unit of measurement for and the formula used to calculate each. 12. State the definition of and write the formula for power factor. 13. Given the power factor and values of X and R in an ac circuit, compute the value of reactance in the circuit, and state the type of reactance that must be connected in the circuit to correct the 14. State the difference between calculating impedance in a series ac circuit and in a parallel ac All material in Adobe PDF format. Easy to use search and print functions. -No personal checks. Personal checks will be returned. -Pennsylvania residents must pay sales tax. (this posting is the responsibility of the poster) |
reginaldbush@dfwind.com (Reginald Bush) for more information. All emails will be forwarded to the poster's actual email address.