week #4 Flashcards
Electrostatic charges are commonly referred to what
static electricity
a build-up or lack of electrons on an insulator is known as what
static electricity
can a static charge be positive and negative
yes
if there is a lack of electrons on an insulator, will the charge be positive or negative
positive charge
in your opinion, the chock from the excess flow of electrons transferring due to the static charge be harmful to sensitive electrical equipment
yes
in your opinion, the chock from the excess flow of electrons transferring due to the static charge can be harmful or even life-threatening to humans.
yes
what is the best example of harmful static electricity found in nature.
electric shock due to the flow of current through the body.
why is magnetism so important to the modern lives we live, with regards to electricity.
It is the force we use to produce the most electrical power in the world.
A magnet that does not require any power of force to maintain its field is considered what.
Permanent magnet.
Are all permanent magnets naturally occurring.
No
What type of permanent magnets are stronger and can maintain their magnetism much longer than natural magnets?
Synthetic permanent magnet.
What are the 3 substances that create naturally occurring Magnets?
Iron, nickel, and colbat.
Is it believed that electrons individually spin when in their orbit around their nucleus?
yes
If electrons spin in the same directions in their orbit does it cancel out the magnetic Effect?
yes
If electrons spin in the opposite direction in their orbit does it cancel out the magnetic
effect?
No
The additive effect of the spinning electrons forms regions in molecular structure of the metal is called what?
Magnetic domains or magnetic molecules.
What theory is question 13, 14,15and 16 referring to?
The electron theory of magnetism.
Can all metals be restructured to be magnetised?
No
Metals that are easily magnetised are known as what?
Ferromagnetic
Metals that can be magnetised but not easily are known as what?
Paramagnetic
Diamagnetic materials have what properties?
Metals or nonmetal materials that cannot be magnetized.
What is Flux?
Magnetic lines of force.
What is the polarity with regard to magnets?
Flux lines are stronger near the pole of the magnet and become weaker as they move farther away.
What is a basic law of magnetism, with regards to attraction?
Unlike poles attract and like poles repeal.
When current flows through a conductor what is created, and don’t say heat?
A magnetic field is formed around the conductor.
So can we use electricity to create a magnet, if so what would we call that type of magnet?
electromagnets.
What is an ampere-turn with regards to an electro magnet?
The ampere-turn is determined by multiplying the number of turns of wire by the current flow.
What is core material when referring to an electromagnet?
Coils can be wound around any type of material to form an electromagnet.
The measuring of a materials ability become magnetised is known to be what?
permeability.
A material’s resistance to magnetism is known as what?
Reluctance.
Saturation with regards to materials be magnetized means what?
When all the molecules of the magnetic materials
are lined up
What’s the rule we use to tell where the North Pole is on an electromagnet, also describe how it’s works?
Left hand rule when the fingers of the left hand are placed around the windings in the direction of electron current flow, the thumb points to the North magnetic pole. If the direction of current flow is reversed the polarity of the magnetic field also reverse
What is it called when you disarrange the molecules inside of a magnet?
Demagnetized
List three methods we can use for demagnification?
Heating, striking and placing the object in the field of a strong magnetic field.
Can we magnetize the metals by striking a magnet in the same direction in that metal?
No
How do we use magnetism to create sound? What is the device known as?
A speaker produces sound by moving a cone the movement causes a displacement of air
How do we create motors using magnetism?
A coil of wire become an electromagnet when current passes through it, the electromagnet enter rates with a permanent magnet, causing the coil to spin
How do we create electricity using magnetism?
Moving a magnet around a coil of wire or moving a coil of wire around a magnet, pushes the electrons in the wire and creates an electrical current
How do we use magnetism to increase or decrease AC voltage? What is the device known as?
Mutual induction is the process by which a coil of wire magnetically induces a voltage into another coil located in close proximity to it
Why is a transformer considered to be one of the most efficient electrical devices?
Because the voltage have been stepped up it travel long distance with low losses.
Why do we use AC for our power grid and not DC
Because it creates lots of magnetic field due to the amount of frequency compared to DC with only one hurts
What is the cost advantage to using a higher voltage AC system?
High voltage system use less energy and with the smaller current less energy is lost high voltage, air conditioning units help save money and deliver efficient cooling
Whenever a conductor cuts through magnetic lines of flux, a voltage is induced into the conductor this statement is known as what
Electromagnetic induction
If magnetic induction was not a real thing, would we be able to generate power make electrical motors transform power use clamp on ammeters?
No
When a conductor is moved up and down through the magnetic field does the direction of the flow of the electrons change
No
What is the word used to describe the direction of the flow of electrons?
The polarity of the induced voltage
If the flow of electrons changed from positive flow to a negative flow, how would an electrician describe this change?
The polarity of the induced voltage is determined by the polarity of the magnetic field in relation to the direction of movement
What rule can be used to determine the relationship of the motion of the conductor in a magnetic field to the direction of the induced current?
Flemming’s left hand generator rule
What are the three factors that determine the amount of induced voltage?
The number of turns of wire the strength of the magnetic field, (flux density) and the speed of the cutting action
How much voltage will be induced when a conductor cuts 100,000,000 lines of magnetic flux in one second
1 volt
Which law states an induced voltage or current opposses, the motion that causes it
Lenz’s law
What is an ion?
A charged atom
A negative ion has an abundance of what
Have gained extra electrons are known as negative ions
Can electrons or currents only travel through a solid conductor
No
When looking at the atomic structure of pure water is pure water, a conductor or an insulator
Insulator
Can dissolved solids in water, create a conductive path for current flow
Yes
If water is an insulator, then why are we so concerned about having electrical appliances around water or swimming near Marina‘s that have power supplies to docking boats
Because pure water is an insulator, but regular water has electrolytes that can be a conductor TDS
TDS when referring to water stands for total dissolved solids so the higher the TDS number in water, the higher the likelihood of atoms in the water that conduct current are present and in a higher concentration saltwater typically contains a higher TDS then fresh which water would conduct electricity better
Salt water
The electrolytes must contain ions of the metal to be plated True or false
True
True or false metal ions are always negatively charged
False in general metals will lose electrons to form positive charge ions and nonmetals will gain electrons to form negatively charge ions
True or false the object to be plated must be connected to the negative power terminal. The negative terminal is called the anode and refers to the terminal where electrons enter the circuit.
False negative terminal are called cathode and positive terminal is an anode
True or false the positive terminal is connected to the same metal that is to form the coating. The positive terminal is referred to as the anode and refers to the terminal that the electrons enter the circuit.
False both objects are submerged in a compressed cyanide solution when power is applied to the circuit positively charged copper ion in the solution moved towards the copper ion contact the object it receives an electron and becomes a neutral copper atom
The process of separating elements electronically is known as what
Electrolysis
Air is an excellent insulator at atmospheric pressure. However, the molecules in the air can become ionized, allowing for current to flow. This flow of current in air is known as what.
Arc
List two factors that allow for ionization in a gas
The amount of voltage and distance of a gab
What technique or tool uses ionization of air to bond two metals together?
Electric arc welder
The amount of voltage or potential an electron must possess is called what
Ionization potential
What are the two factors that determine the amount of voltage required to cause conduction in a gas field envelope?
Atmospheric pressure and the type of gas in the surrounding atmosphere
What is the term used when an electron is freed from a cathode travelling towards an anode and it collides with molecules from a gas?
Electron impact
Can we use electron impact to create light and list three types of light created?
Yes, sodium vapour mercury vapour and neon
Can we use different voltage and gases to create different colours and brightness of light?
Yes
What is the name of the device that uses conduction in a gas that when the cathode rays struck metal and glass it altered the radiation of the atoms which would allow the rays to pass through a human and take a snapshot of the internal composition of a human?
X- ray
What in nature creates the northern lights?
Ionization of gas in the aurora borealis.
