Bakers School of Aeronautics Oral Prep

Bakers School of Aeronautics Oral Prep What is the most important law applicable to the study of electricity? - Ohm's Law What are the elements of Ohm's Law? - Voltage, Current & Resistance What are four sources of electrical power? - Mechanical, chemical, photoelectric and thermal What does an electrical circuit consist of? - 1. a source of electrical pressure 2. resistance 3. conductors What represents capacitance in an AC circuit? - a capacitor What is the function of a capacitor? - to store electricity What is the unit of measure for capacitance? - Farad What is inductance? - When voltage is induced by magnetic flux What is an example of an inductor in a magneto? - the coil What is impedance? - total opposition for AC to flow What is the unit of measurement for impedance? - Ohms What are two things that happen when current flows through a conductor? - a magnetic field; heats up What are the four factors that affect the resistance of an electrical conductor? - gauge, length, temperature and material What is the unit of measurement of power in a DC circuit? - watt What is a kilowatt? - 1,000 watts In a DC circuit, what occurs when voltage is increased while resistance remains constant? - increase in current What are the three types of DC electrical circuits? - series, parallel, and complex A 24 volt lead-acid battery has how many cells? - 12 cells. Each rated at 2 volts. What are the units that battery capacity are measured in? - Ampere-hours What should be the specific gravity of the electrolyte in a fully charge lead acid battery? - between 1,275 and 1,300 What instrument is used to determine the specific gravity of electrolyte in a lead acid battery? - a hydrometer Why can a hydrometer NOT be used to determine the charge of a nickel-cadmium battery? - Specific gravity of the electrolyte in a nickel-cadmium battery does not change appreciably When using a hydrometer to check the charge of a lead-acid battery, at what temperatures must a correction factor be applied to the reading? - above 90F or below 70F What is the electromagnetic induction? - transfer of electrical energy by means of a magnetic field How are battery compartments protected against corrosion? - coated with special corrosion resistant paint What should be the correct electrolyte level in a properly serviced battery? - 3/8 inches above the plates What are paralleling generators and how is the load distributed? - when two or more generators are operated at the same time; must be shared equality Describe a no-trip circuit breaker (trip free). - makes it impossible to manually hold the circuit closed Can you store Ni-cad and Lead-acid batteries