General aviation electricity ch. 2 and ch.3

Ampere

1 blank is the amt of current thru a 1 ohm resistance that has one volt of potential difference applied across it

746 W

1 horsepower is equal to

True

1 horsepower is equal to 3 quarter kilowatt

Work on circuits with power disconnected whenever possible

1 of the best safety rules is to

Resistance

A blank is a material whose elements have an atomic structure that allows free electrons to drift thru if with more or less force applied

Fusible

A blank resistor is a wire-wound resistor made to burn open easily when the power rating is exceeded

False

A decade resistance box is typically used as a potentiometer

Decade box

A device that is used to provide any one resistance with in a wide range of values is a

False

A graph referred to as the volt-ampere characteristic R shows how much resistance exists for different currents

Volt ampere characteristic of R

A graph that shows how much current a resistor allows for different voltages is called the

False

A potentiometer can never be wired as a rheostat

Three terminals

A potentiometer has

True

A resistance can be considered some material whose elements have an atomic structure that allows free electrons to drift through it with more or less force applied

Limit current or produce a voltage drop

A resistor is used to

True

A resistor that is color-coded red, green, red, has a value of 2500 ohms

Zero

A resistor with a single black band around the center of the resistor body has a resistance

True

A rheostat has two terminals and a potentiometer has three terminals

False

A straight line graph shows that a resistor is nonlinear

Linear

A straight-line graph shows that a resistor is

Shock

A sudden involuntary contraction of the muscles, with a feeling of pain, caused by current thru the body is referred to as

True

A thermistor is a thermally sensitive resistor whose resistance value changes with changes in operating temperature

Rheostat

A variable resistance with two terminals that is connected in series with the load

Tolerance

Aging, which is normal resistor heating over a long period of time causes the resistor to exceed its

Tungsten

An example of a nonlinear resistance is the

True

An important safety tip to follow is to keep yourself insulated from earth ground when working on power-lines

An open circuit

As measured with an ohmmeter, infinite ohms means

Surface

Blank mount resistors are constructed by depositing a thick carbon film on a ceramic base

Wire-wind, high wattage resistors

Commercial rheostats are typically

0.001

Concerning electric shock, the threshold of sensation occurs when the current thru the body is only slightly above blank

Derated

For ambient temperatures greater that 70 degrees Celsius, the power rating of a resistor must be

5A

How much current is needed for a 600-W, 120-V toaster

2500 ohms

If a resistor is color coded red blue and orange what is its resistance value

Vary

If the resistance in a circuit is kept the same, but the voltage is varied, the current will blank

Carbon

In electronic equipment, the resistor most commonly used is the

False

Metal-film resistors are made of finely divided carbon or graphite mixed with a powdered insulating material

Metric

Multiple and submultiple values used in electronic applications are based on the blank system of units

False

Note that the resistor itself is very likely to develop a short circuit because of the nature of its construction

Inversely

Ohm's law states that current is blank proportional to resistance

True

Ohm's law states that the amount of current is directly proportional to the voltage and inversely proportional to the resistance

True

One ampere is the amt of current thru a 1 ohm resistance that has one colt of potential difference applied across it

IxV

Power is equal to

True

Power is equal to voltage times current

True

Power is generated by the source of applied voltage and consumed in the resistance

Ohmmeter

Resistance is measured with an

False

Resistors have a relatively short self life and only keep their characteristics for six to eight months

Lower

Resistors with higher resistance values usually have blank wattage ratings

Variable resistors

Rheostats and potentiometers are referred to as

Wire-wound

Since they are generally used for high current applications, blank resistors are available in wattage ratings from 1W up to 100W or more

Resistance

Some material whose elements have an atomic structure that allows free electrons to drift through it with more or less force applied is a

Tolerance

The amt by which the actual resistance can differ from the color coded value is the

False

The amt by which the actual resistance can differ from the color coded value is the positive temperature coefficient

1 ohm

The amt of opposition in a resistance that allows 1 ampere of current with 1 volt applied is

True

The fact is that high/voltage circuits usually do have small values of current in electronic equipment

True

The main function of a resistor is to limit the amt of current or produce a desired drop in voltage

Max working voltage rating

The max allowable voltage that a resistor can safely withstand without internal arcing is called the

True

The max working voltage of a resistor is the max allowable voltage that the resistor can safely withstand without internal arcing

M

The metric system uses what letter 1 million

An open

The most common trouble in resistors is

True

The most common trouble in resistors is an open

Directly

The ohm's law formula stars the V and I are blank proportional for any one value of R

It's physical size

The power of wattage rating of a resistor is determined

Size

The power rating is a property of a resistor that depends on the resistor's

Electric power

The rate at which charge is forced to move by voltage is called

Power

The rate of doing work is

3 digit number printed on the film or body

The resistance value of a chop resistor is determined

False

The two main characteristics of a resistor are its resistance in ohms and its tolerance in mhos

False

The unit of electric power is the joule

Taper of the control

The way resistance varies with shaft rotation in a variable resistor is called the

Watt

The work done in one second by 1 volt of potential difference in moving 1 coulomb of charge is the

Resistance in ohms and power eating in watts

Two major characteristics of a resistor are

Carbon type

Variable resistors can be wire wound

True

Variable resistors can be wire wound or carbon type

False

We pay for electricity in kilowatts

Worn or dirty resistance element

What is indicated when a volume of tone control makes a scratchy noise as the shaft is rotated

Heat

What is produced when current flows in a resistance

Joule

What is the basic practical units of energy

1 volt

What is the potential difference across a 1 ohm resistance that has 1 ampere of current thru it

200W

What is the power in a circuit where the source of 100V produces 2A in a 50 omega R

Fusible

What is the resistor called that is designed to burn open easily when the power rating is exceeded

2

What is the resistor safety factor that allows the resistor to operate without breaking down from excessive heat

Kilowatt-hours

What is the unit commonly used for large amts of electrical energy

Parallel resistance paths

What may cause a much a lower resistance value to be displayed on an ohmmeter when checking resistance in a circuit

Power supply

What piece of equipment provides a variable dc output voltage to electronic circuits under test

Rheostat

What resistive device is generally used to control relatively large values of current in low resistance circuits for ac power applications

Wire wound

What type of resistor is constructed by wrapping resistance wire around an insulating

Metal-film

What type of resistor is formed by spraying a thin film of metal onto a ceramic substrate and the cut in the form of a spiral

Thermistor

What type of resistor is frequently used in electronic circuits in which it is desired to provide temperature control

Wire wound

What type of resistor is typically used as a precision resistor

True

When checking resistance in a circuit, it is important to be sure there are no parallel resistance paths

Almost indefinitely

When not used, resistors generally keep their characteristics

Abscissa

When plotting a graph of current versus voltage, the horizontal axis is referred to as the x axis or as the blank

Less resistance

When the applied voltage is constant, the current is more with

Short

When the current flow in a circuit becomes excessive, a resistor is more likely to

False

Whenever there is current through a resistance, it must have a potential difference across its two ends equal to the IR sum

IR

Whenever there is current thru a resistance, it must have a potential difference across its 2 ends equal to the blank

R=V/I

Which of the following formulas correctly expresses Ohm's law

True

Wire wound resistors are larger and have higher wattage ratings than carbon resistors

True

Zero-ohm resistors are commonly found on printed circuit boards