Midterm Flashcards
The current, voltage, power, and resistance in a series circuit can be found by using ___ law
Ohm’s
When a circuit has only one path, the____ is the same at any point
Current
A(n) _____ ground symbol is used to symbolize a ground point made by physically driving an objest such as a rod or pipe into the ground
Earth
A circuit that has only one path for current flow
Series
Wire wound resistors are often used because they can
Operate at high power levels than other resistors
Point that is used as a common connection for other parts of a circuit is called a
Chasis point
A resistor made by applying a film of carbon to a ceramic rod is
A carbom film resistor
What does the fourth band of a color on a 5 band resistor indicate?
Tolerance
A device that is designed to open and disconnect a circuit in the event of excessive current is a
Fuse
A variable resistor with 3 terminals is called a
Potentiometer
2 resistors in a series circuit have voltages of 25 and 60 volts, what is the applied voltage?
85v
A series corcuit has a total resistance of 240 ohms and a current flow of 4 amps, what is the applied voltage?
R x I, 240 x 4=960 v
Resistor that is made by winding a piece of resistive wire around a ceramic core
Wire wound resistor
The force that pushed the electrons through resistance
Voltage
A series circuit has a total resistance of 180 ohms and applied voltage is 120 v. What is the current flow?
I/R, 120/180=0.6667
The resistor circuit has a total power of 25 W. two of the resistors dissipate 10 w and 5 w. How much power does the 3rd resistor dissipate?
R3= Rt-R1-R2, 25-10-5=10
What are the rules for a parallel circuit?
1) total current flow is equal to the sum of currents through all branches
2) voltage drop across any branch is equal to the source voltage
3) total resistance is always less than the resistance of the lowest value of resistor in the branch
What are series circuit rules
1) current is the same at any point in the circuit
2) total resistance is the sum of individual resistors
3) applied voltage is equal to the sum of voltage drops across all resistors
How many valence electrons do insulators have?
7-8
What are semiconductors?
Materials that are neither good nor bad conductors
How many valence electrons are in semiconductors?
4
What are 6 basic methods if producing electricity
Magnetism Chemical action Pressure Heat Friction Light
What are 5 basic electrical effects
Magnetism Chemical reactions Pressure Heat Light
What are conductors?
Materials that provide an easy path for electron flow
How many valence electrons in conductors?
1-3
What is voltage?
Potential difference between 2 points of conducting wire
What is a volt
Amount of potential necessary to cause 1 coulomb to produce 1 joule of work
What is an ohm
Unit of resistance to current flow
What is a watt
Amount of power being used in a circuit
