DC Circuits Unit 5: Resistors
In the color code, what is the value of black?
0
In the color code, what is the value of brown?
1
A circuit has a 10 Volt power supply, and a 1/2 W 100 Ohm resistor. How much power is being produced? Will this resistor be damaged?
1 watt. yes
In the color code, what is the tolerance of brown?
1%
What tolerance range is common for metal glaze resistors?
1-2%
What are the power ratings of carbon resistors?
1/2, 1, and 2 watts
In the color code, what is the tolerance of silver?
10%
A rheostat, a type of variable resistor has how many terminals?
2
In the color code, what is the value of red?
2
In the color code, what is the tolerance of red?
2%
A resistor has color bands of orange, blue, yellow, and gold. What are the resistance and tolerance of this resistor?
360 Kohm, 342 Kohm - 378 Kohm
In the color code, what is the value of yellow?
4
In the color code, what is the value of green?
5
In the color code, what is the tolerance of gold
5%
In the color code, what is the value of blue?
6
In the color code, what is the value of violet?
7
In the color code, what is the value of gray?
8
In the color code, what is the value of white?
9
A 10000 Ohm resistor has a tolerance of 5%. What are the minimum and maximum values of this resistor?
9.5 Kohm - 10.5 Kohm
On a print, a variable resistor symbol looks like a fixed resistor symbol, but with what going through or under it?
an arrow
What type of fixed resistor is considered the most common?
carbon resistor
What are the five types of fixed resistors?
carbon, metal film, carbon film, metal glaze, and wire-wound
Using the color code, what does it mean when the 3rd color is gold?
divide by 10
Using the color code, what does it mean when the 3rd color is silver?
divide by 100
What is the second function of resistors?
divide voltage
What material is combined with metal to make metal glaze resistors?
glass
What is a disadvantage to wire-wound resistors?
inductance
What is the first function of a resistor in a circuit?
limit flow
A 1 watt, 350 ohm resistor is connected to 24 volts. Is this resistor operating within its power rating? yes/no
no
Why are wire-wound resistors mounted vertically?
to make a chimney effect and dissipate heat efficiently
Although being more expensive, why are metal film resistors considered superior to carbon?
values do not change with age and their tolerance is usually less than 2%
What is a big disadvantage in using carbon resistors?
values generally increase with age or heat
What type of resistor can be adjusted over a range?
variable
What three factors determine the resistance of a wire-wound resistor?
wire material, diameter, and length
A .5 watt, 2000 ohm resistor has a current flow of 0.01 A through it. Is the resistor operating within its power rating? yes/no
yes
In the color code, what is the tolerance of no color?
20%
A potentiometer, a type of variable resistor, has how many terminals?
3
In the color code, what is the value of orange?
3
What can wire wound resistors do that other resistors can't?
operate at high temperatures
What is a circuit that contains no resistance called?
short circuit
