Electricity 1-7 Ch 1 Review Flashcards
Ben Franklin believed in 2 kinds of electricity, what are they?
Positive and negative
The Greeks discovered electricity when charged amber attracted what?
Dried leaves
Today, scientists think electricity is produced by very tiny particles called _________ and __________.
Protons and electrons
A water molecule is made of _________?
2 hydrogen atoms and 1 oxygen atom
What is matter?
Anything that has weight and occupies space
What is an element?
The basic materials that make up all matter
1 molecule of salt is made of:
Sodium & chloride
An atom is made of what 3 parts?
Protons, neutrons, and electrons
The nucleus contains:
Protons and neutrons
The number of protons in the nucleus shows:
How an atom differs from one another
Info about protons:
Positively charged, 1/3 the diameter of an electron, and 1840 times heavier than an electron
How many electrons does copper have?
29
True or false: opposite charges attract, like ones repel.
True
What do you call a charged atom?
Ion
What makes an atom neutral?
Same number of protons and electrons
How many shells does hydrogen have?
1
What is a valence shell?
The outer most shell of an atom
What type of atoms make the best conductors?
Ones with only 1 electron
What do you call a material from which electrons are difficult to free?
Insulators
Max number of shells on an atom?
7
Max number of electrons in second shell of an atom?
8
What is electric flow?
The flow of free electrons
6 ways electricity is produced?
CHP, FML. Chemical, heat, pressure, friction, magnetism, light
Name of effect of pressure in causing electric charges?
Piezoelectricity
What small particles is light made of?
Photons
How fast does electric current travel?
The speed of light, 186,000 mi/sec
For every electron that leaves the negative side of the battery…
An electron enters the positive side
What happens when a conducting wire is put directly across the terminals of a battery?
A short circuit is produced
How does electron current flow?
From low to high potential, or between any difference of potential
What determines the electric charge of an object?
The number of electrons lost or gained
Light Can be produced by electricity without heat via:
Fluorescence, phosphorescence, and electroluminescence
Any conductor that carries electric current will act like a:
Magnet
How to demagnetize a magnet?
Strike, heat, or place in a rapidly reversing magnetic field
Where does a compass needle point?
North magnetic pole
Which pole do flux lines come out of?
North Pole
True or false: a close-wound solenoid will create a stronger magnetic field
True
What is a holding relay?
A relay with an extra set of contacts to keep current flowing through the relay even after the main switch is released
A buzzer operates similarly to a relay except:
the contacts are arranged so that the electromagnetic coil cannot stay energized continuously
What does a commutator in a generator do?
Keeps current flowing in the same direction
If a commutator is not used in a generator, what kind of current will be produced?
AC
