Transformer with a turns ratio greater than one is a __________ ____________
__________.
step-up transformer
Three ways that electrification can be created.
Contact, friction and induction
What is the turns ratio formula?
N s
_____
N p
Unlike charges __________ and like charges _____________.
attract, repel
What are the two units of magnetic field strength?
Tesla, Gauss
What is the unit of electric potential? What is its symbol?
volt, V
What is an example of direct current?
battery
The autotransformer has _________ winding?
one
An insulator is any material that (does or does not) allow electron flow ?
does NOT
In an induction motor , do wires have to touch ?
no
A _______________ is anything that electrons flow easily through.
conductor
The charges on an electrified object are distributed ______________ throughout the object. ( in the center, topside or evenly)
evenly
What circuits are better especially when using Christmas lights?
parallel
What are two examples of conductors?
metal and water
What type of material can be made magnetic when placed in an external magnetic field?
ferromagnetic
What is the unit of electric potential ? What is its symbol?
volt, V
Electrification occurs through the movement of _________________.
electrons
The smallest unit of electric charge is the _________________?
electron
The Earth behaves as a huge reservoir for stray electric charges. What is this called?
electric ground
What do you have to add to increase the magnetic intensity of an electromagnet?
an iron core
What is the study of electric charges in motion?
Electrodynamics
Any charged particle in motion creates a ________________ ________________.
magnetic field
Electrostatics is the study of __________________ electric charges.
stationary
When a group of dipoles are aligned, they create a _____________. What is an example of this?
magnetic domain, credit card strip
How is AC current represented?
sinusoidal wave
What is a coil of wire called?
solenoid
Electrostatic force is _____________ proportional to the distance between charges and ______________ proportional to the product of the charges?
inversely, directly
The force between magnetic poles is proportional to the _________________
of the magnetic pole strengths, divided by the ________________ of the distance between them.
product, square
In the United States, AC current occurs every ________________ second?
1/60
What is the formula for Ohm's Law?
V= IR
How is electrical power measured?
watts
Where are electrostatic charges concentrated?
on the sharpest curve
What is the most efficient type of transformer?
shell type
An electric potential applied to a conductor produces a ________________ and
an _____________________?
electric current, magnetic field
Electrostatic force is strong when objects are close, but decrease as objects separate. What relationship does this show?
Inverse square law
The rotation of electrons on their axis is the property called ?
electron spin
A semiconductor is any material that can behave as an _________________ AND
a ________________.
insulator, conductor
Electrons that flow in only one direction make up __________ current.
Electrons that flow alternatively in opposite directions make up
_____________ current .
DC, AC
What results in reduced electric current?
Increasing electric resistance
What are two examples of semiconductors?
silicon and germanium
How is alternating current produced?
by a generator
A transformer with a turns ratio less than one is a _____________ _____________
______________.
step-down transformer
What is the formula for Electric Power? What do symbols stand for?
P = IV,
P=power (watts), I= amps, V=volts
Electric fields radiate ________ from a positive charge and radiate
______________ a negative charge.
out, towards
What powers the rotating anode of an x-ray tube?
An induction motor
What device changes the intensity of alternating voltage and current?
transformer
What do you get when you add resistance to a circuit?
heat
What are three examples of insulators?
glass, clay and rubber
What is an example of direct current?
battery
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