Definitions I
Process by which a changing magnetic field generates a voltage
Electromagnetic Induction
the number of cycles that occur during a period of time
Frequency
Magnets have both a ____________ and a _________________.
North pole/south pole
Magnetic Field lines surrounding a magnet always form...
closed loops
What kind of field surrounds an electric charge at rest?
Electric field
a machine that converts mechanical energy into electrical energy
Generator
device that is used for increasing or decreasing voltages of AC current through electromagnetic induction
Transformer
What kind of field surrounds an electric charge in motion?
Magnetic field
What are the two main machines responsible for getting power into our homes?
Generators and transformers
AC stands for...
Alternating current
type of periodic motion in which the restoring force is proportional to the object’s displacement
Simple Harmonic Motion
standard unit of frequency equal to one cycle per second
Hertz
Hertz
What three things does the 2nd right hand rule keep track of?
Magnetic field
Current
Force
What is the voltage range coming out of a standard home outlet in the United States?
110-120 volts
standard unit of measure for a magnetic field
Tesla
law which states that an induced voltage is equal to the rate of change of the magnetic flux within the system
Faraday's Law of Induction
What is the voltage range coming out of a standard home outlet in other countries (not the US)?
220-240 volts
Mutual inductance
What is a transformer called that increases voltage?
Step-up transformer
closed loops beginning at the north pole of a magnet and ending at its south pole which do not cross each other; identifies the location of a magnetic field
Magnetic Field Lines
the energy of motion
Kinetic Energy
What does a step-up transformer step-up: energy, current or voltage?
Voltage
The period for a pendulum depends on two things:
Gravity
Length (of rope, etc.)
A generator converts __________ to _____________
work to energy
law which states that an induced current generated by an emf points in a direction so that the magnetic field it creates will oppose the change in magnetic flux
Lenz's Law
back and forth motions, those responsible for the swaying of the Millennium Bridge
Oscillations
A motor converts ___________ to _______________
electricity to work
Why do pendulums not swing endlessly in real life?
They come into contact with air particles
What nutrient did we extract with the magnet from the Total cereal in our lab from a few weeks ago?
Iron
area surrounding a magnetic material or a moving electric charge within which the magnetic force acts
Magnetic Field
the fixed interval of time that occurs for each cycle of the object’s motion
Period