Fundamentals of Electricity and Electronics

Study Materials

AMT-G, FAA-H-8083-30, AC 43.13-1

Typical Oral Questions

  1. What is the basic unit of voltage?

    The volt.

  2. What is the basic unit of current?

    The amp.

  3. What is the basic unit of resistance?

    The ohm.

  4. Which law of electricity is the most important for an aircraft mechanic to know?

    Ohm’s law.

  5. What are the three elements in Ohm’s law?

    Voltage, current, and resistance (volts, amps, and ohms).

  6. What are five sources of electrical energy?

    Magnetism, chemical energy, light, heat and pressure.

  7. What four things affect the resistance of an electrical conductor?

    The material, the cross-sectional area, the length and the temperature.

  8. How can you tell the resistance of a composition resistor?

    By a series of colored bands around one end of the resistor.

  9. What three things must all electrical circuits contain?

    A source of electrical energy, a load to use the energy, and conductors to join the source and the load.

  10. What is the purpose of a capacitor?

    To store electrical energy in electrostatic fields.

  11. What is the basic unit of capacitance?

    The farad.

  12. Why should electrolytic capacitors not be used in an AC circuit?

    They are polarized. An electrolytic capacitor will pass current of one polarity, but will block current of the opposite polarity.

  13. What is meant by inductance?

    The ability to store electrical energy in electromagnetic fields.

  14. What is the basic unit of inductance?

    The henry.

  15. What is meant by impedance?

    The total opposition to the flow of alternating current. It is the vector sum of resistance, capacitive reactance and inductive reactance.

  16. How can you find the polarity of an electromagnet?

    Hold the electromagnet in your left hand with your fingers encircling the coil in the direction the electrons flow. Your thumb will point to the north end of the electromagnet.

  17. In what units is impedance measured?

    In ohms.

  18. What is the basic unit of electrical power in a DC circuit?

    The watt.

  19. What is meant by a kilowatt?

    1,000 watts.

  20. What happens to the current in a DC circuit if the voltage is increased but the resistance remains the same?

    The current increases.

  21. What are three types of DC circuits, with regard to the placement of the various circuit components?

    Series, parallel and series-parallel.

  22. How many cells are there in a 24-volt lead-acid battery?

    12.

  23. What is the specific gravity of the electrolyte in a fully charged lead-acid battery?

    Between 1.275 and 1.300.

  24. What is the range of temperatures of the electrolyte in a lead-acid battery that does not require that you apply a correction when measuring its specific gravity?

    Between 70 degrees and 90 degrees Fahrenheit.

  25. What instrument is used to measure the specific gravity of the electrolyte in a lead-acid battery?

    A hydrometer.

  26. How is a lead-acid battery compartment treated to protect it from corrosion?

    Paint it with an asphaltic (tar base) paint or with polyurethane enamel.

  27. What is used to neutralize spilled electrolyte from a lead-acid battery?

    A solution of bicarbonate of soda and water.

  28. How high should the electrolyte level be in a properly serviced lead-acid battery?

    Only up to the level of the indicator in the cell.

  29. What precautions should be taken in a maintenance shop where both lead-acid and nickel-cadmium batteries are serviced?

    The two types of batteries should be kept separate, and the tools used on one type should not be used on the other.

  30. Why is a hydrometer not used to measure the state of charge of a nickel-cadmium battery?

    The electrolyte of a nickel-cadmium battery does not enter into the chemical changes that occur when the battery is charged or discharged. Its specific gravity does not change appreciably.

  31. What is used to neutralize spilled electrolyte from a nickel-cadmium battery?

    A solution of boric acid and water.

  32. What is meant by electromagnetic induction?

    The transfer of electrical energy from one conductor to another that is not electrically connected

  33. How many ohms are in a megohm?

    One million (1,000,000).

  34. What part of an amp is a milliamp?

    One thousandth (0.001).

Typical Practical Projects

  1. Compute the voltage and current in an electrical circuit specified by the examiner.
  2. Find the total resistance of a combination of resistors that are connected in series.
  3. Find the total resistance of a combination of resistors that are connected in parallel.
  4. Find the power used by an electric motor when the voltage and the current are known.
  5. Identify for the examiner electrical symbols used in an aircraft service manual.
  6. Measure the voltage drop across each of the components in a series circuit specified by the examiner.
  7. Check an electrical circuit for opens or shorts, using an ohmmeter.
  8. Measure the current in an electrical circuit, using a multimeter.
  9. Measure the resistance of several components, using an ohmmeter.
  10. Use an electrical schematic diagram to locate the source of a malfunction described by the examiner.
  11. Measure the state of charge of a lead-acid battery.
  12. Correctly connect a lead-acid battery to a constant-current battery charger.
  13. Correctly remove electrolyte that has been spilled from a lead-acid battery, and protect the surface around the battery from corrosion.
  14. Select the proper size terminal and correctly swage it to an electrical wire.
  15. Given a group of composition resistors, identify the resistance and tolerance of each one by the color code.
  16. Demonstrate to the examiner the correct way to remove and install an aircraft lead-acid battery.
  17. Demonstrate to the examiner the correct way to check a solid-state diode to determine whether or not it is good, or if it is open or shorted.

[10-2024]