Resistors Flashcards
The amount of resistance to current is measured in ____. The more of it a resistor has, the higher its resistance.
Ohms
Just as a resistor is abbreviated with the letter R, ohm is abbreviated with the Greek letter _____?
Just as a resistor is abbreviated with the letter R, ohm is abbreviated with the Greek letter omega (Ω).
What is inversely proportional with resistance?
Current
The resistor is represented by what schematic symbol?
The resistor is represented by either a rectangle or a zig-zag line.
Resistors are classified in what two types?
Fixed or Variable
Fixed resistors are classified in what three categories?
General purpose
power
precision
The most widely used general purpose resistor is the _____. Carbon resistors are identified by ________which indicate their value.
The most widely used general purpose resistor is the carbon resistor. Carbon resistors are identified by color bands which indicate their value.
What’s the difference between a carbon compostion and carbon film resistor?
CARBON COMPOSITION - A mixture of materials, mostly carbon, that is formed into a cylindrical shaped body. The amount of the other materials determines the resistance.
CARBON FILM - A strip of carbon that is wound around a core. The length of carbon determines the resistance.
Which resistors is used when a circuit has a large amount of current flow.
Power resistors
Which resistors are used when an exact value of resistance is necessary for correct circuit operation?
Precision
What are the two types of variable resistors?
What is the schematic symbol?
Which one is used for low or high current?
Potentiometers are used when circuit current flow is low.
Rheostats are used when circuit current flow is high.
What are the three general characteristics of resistors?
Power rating
Tolerance
Ohmic Value
The power rating of a resistor describes what?
The power rating describes the amount of heat a resistor can safely give off.
Resistance is a lot like friction; both act to oppose motion and, in doing so, generate heat.
Carbon composition resistors typically come in five sizes and power ratings. The power rating is measured in what?
Carbon composition resistors typically come in five sizes and power ratings. The power rating is measured in watts.
The power rating on a wound resistor (power resistor) is identified by the what markings?
PW or CW.
The letters used to identify the power rating can vary from one manufacturer to another.
______ is the amount of difference that is acceptable between the measured ohmic value and the indicated value. This is also known as the percent of error.
Tolerance is the amount of difference that is acceptable between the measured ohmic value and the indicated value. This is also known as the percent of error.
EX:
If a 2000 ohm resistor has a tolerance of 1%, its actual value could be anywhere between ___ and ____ohms.
If a 2000 ohm resistor has a tolerance of 1%, its actual value could be anywhere between 1980 and 2020 ohms.
2000 x 1% = 20
2000 - 20 = 1980
2000 + 20 = 2020
Most carbon based resistors have a _____ tolerance.
Precision resistors have a tolerance of ____or less.
Most carbon based resistors have a 5% tolerance.
Precision resistors have a tolerance of 1% or less.
The carbon resistor’s tolerance is indicated by which color band?
The carbon resistor’s tolerance is indicated by the 4th color band.
The precision resistor’s tolerance is indicated by what?
The precision resistor’s tolerance is indicated in a code.
Name the general discription of the four color bands
The first band represents the first number in the resistance value.
The second band represents the second number in the resistance value.
The third band is the multiplier or number of zeros to add to the value of the resistor.
The fourth band indicates tolerance.
This is a 2000 ohm resistor with a tolerance of 5%.
What is the resistor color code acronym?
Big boys rape our young girls but Violet gives willingly. Get Some Now!!
What does the four digits 3572 indicate?
Ohmic value
(35700 ohms or 35.7 kΩ.)
What is the meaning of (F)? What if it had been another letter?
What does the J stand for?
The first letter (F) is the tolerance. The tolerance codes are:
F - 1%
G - 2%
J - 5%
The second letter (J) is used for special purposes. In this case, the J means this resistor meets military specifications.
What does the code RN65D mean?
The first letter indicates the component is a resistor.
The second letter is the style:
N - Metal Film
W - Wire Wound
CR - Carbon
The two numbers indicate the power rating, or watt size.
55 - 1/8 watt
60 - 1/4 watt
65 - 1/2 watt
The last letter indicates the temperature coefficient. This tells the user how much the ohmic value can change as a result of a temperature change.
