NAVEDTRA 14173A, NEETS Mod. 1, Ch.3 Flashcards
What is any device called in which an electrical current flows and which changes this electrical energy into a more useful form?
Load
Which device furnishes the electrical energy used by the load?
Source
What permits control of the electrical device and interrupts the current delivered to the load?
Switch
What is the technician’s main aid in troubleshooting a circuit in a piece of equipment?
Schematic Diagram
Who proved by an experiment that a precise relationship exists between current, voltage, and resistance?
George Simon Ohm
What is current inversely proportional to?
Resistance
What is a basic tool used to solve electrical problems?
Algebra
What can be constructed to easily analyze a circuit?
Graph
Which axis on a graph is known as the X-AXIS?
Horizontal
What is the rate at which work is being done referred to as?
Power
What unit is electric power rate measured in?
Watts
What is the basic unit of power?
Watt
What indicates the rate at which devices convert electrical energy into another form of energy?
Power rating
In most circuits, the actual power used by a resistor is considerably less than the power rating of the resistor because a safety factor of what percent is used?
50%
When resistors with wattage ratings greater than how many watts are needed, wirewound resistors are used?
5
Wirewound resistors are made in values between 5 and how many watts?
200
Which electrical device property is the ratio of power converted to useful energy divided by the power consumed by the device?
Efficiency
How many watts are required to equal one horsepower?
746
What is a complete conducting pathway called?
Electric circuit
Which type of circuit contains only one path for current flow?
Series
Each of the resistors in a series circuit consumes power which is dissipated in the form of what?
Heat
The total resistance of a series circuit is equal to the sum of the what?
Individual resistances
Which resistor value is the voltage drop across a resistor in a series circuit proportional to?
Ohmic
What year did G. R. Kirchhoff extend the use of Ohm’s law by developing a simple concept concerning the voltages contained in a series circuit loop?
1847
Which law states that “The algebraic sum of the voltage drops in any closed path in a circuit and the electromotive forces in that path is equal to zero.”?
Kirchhoff’s voltage law
What are emf sources that would tend to force current in opposite directions said to be?
Series opposing
What is an arbitrarily chosen point to which all other points in the circuit are compared?
Reference point
Which term is used to denote a common electrical point of zero potential?
Ground
What is the common ground for the many electrical circuits in most electrical equipment?
Metal chassis
What is a circuit said to be when a break exists in a complete conducting pathway?
Open
Which term represents a quantity so large it cannot be measured?
Infinity
What is an accidental path of low resistance which passes an abnormally high amount of current called?
Short circuit
All sources of electromotive force have some form of internal resistance which causes a drop in what as current flows through the source?
Terminal voltage
Which type of circuit has more than one current path connected to a common voltage source?
Parallel circuit
How many resistances at a minimum must parallel circuits contain which are not connected in series?
Two
What is the total resistance of resistors in parallel also referred to as?
Equivalent resistance
The equivalent resistance of a parallel circuit is always less than the resistance of any what?
Branch
Any complex circuit consisting of resistances can be redrawn (reduced) to a basic equivalent circuit containing the voltage source and a single resistor representing total resistance. This process is called reduction to a what?
Equivalent circuit
Which type of circuits consist of both series and parallel elements?
Combination
What are the points where the current divides called?
Junctions
What are installed in equipment circuits to prevent damage caused by increases in current?
Fuses
Approximately what percent of the load current should the current in a voltage divider resistor equal?
10%
Which type of current does not flow through any of the load devices?
Bleeder
The resistance of the human body cannot be relied upon to prevent a fatal shock from how many volts or less?
115
Fatalities from voltages as low as how many volts have been recorded?
30
Tests have shown that body resistance under unfavorable conditions may be as low as 300 ohms, and possibly as low as how many ohms from temple to temple if the skin is broken?
100 ohms
What is used to fight electrical fires because it is nonconductive and the safest to use in terms of electrical safety?
Carbon Dioxide (CO2)
What is the process by which a person who has stopped breathing can be saved called?
Artificial ventilation
Records show that seven out of ten victims of electric shock were revived when artificial respiration was started in less than how many minutes?
3 minutes
Which technique has been developed to provide aid to a person who has stopped breathing and suffered a cardiac arrest?
Cardiopulmonary Resuscitation (CPR)
