delmar 1
electroscope can be used to determine a polarity of an electrostatic charge t f
t
lightning is the result of static charges built in clouds that contain large amounts of moisture t f
t
lightning rods provide an easy path to ground or current to flow t f
t
matter has mass and occupies space t f
t
resistors have a power rating in watts that should not be exceeded or the resistor will be damaged t f
t
the polarity of the field in a speaker is determined by the direction of current flow t f
t
using the SI sys the amount of substance is known as a unit of mole t f
t
it is believed that when electron spin on their axis as they orbit the nucleus of the atom the spinning motion causes each electron to become blank a tiny permanent magnet a large permanent magnet a magnetite a paired magnet
a tiny permanent magnet
which of the following is an example of nuisance static charge automobile moving through dry air spray painting a copying machine lightning
autombile moving though dry air
which theory states that current flow is produced in an electron from one atom knocks electrons of another atom out of orbit bump theory bhor theory seebeck theory striking theory
bump theory
what causes a static charge in a clothes dryer clothes moving through the dry air adding a dryer sheet not using a grounding plug using too high of a heat setting
clothes moving through the dry air
in standard metric prefixes what is the first step above the base unit deka hecto kilo centi
deka
what type of magnetic depends on flowing current to produce a magnetic field an electro magnet permanent magnet temporary magnet domain magnet
electro magnet
three principle parts of an atom
electron neutron proton
A thundercloud contains only positive charges t f
f
there are many more resistance available for ten percent tolerance reisistors than for 1 percent tolerance resistors. tru false
false
any object repelled by a piece of what rubbed on silk would have a positive charge mica wool glass hard rubber
glass
nylon is an excellent _ material and is used in most carpets insulating resisting attracting grounding
insulating
what contains 7 or 8 valence electrons insulator semi conductor conductor electron
insulator
who proposed in 1808 that all matter was composed of atoms john dalton
john dalton
lodestone is a name for a naturally occurring magnetic material thats also called __ lead magnetism copper magnetite
magnetite
rubbing a hard rubber rod on a piece wool produces what kind of charge neutral negative positive no charge
negative
in a dc circuit the current is directly pro proportional to voltage and inversely proportional to resistance is known as _ law amperes coulombs ohms volts
ohm
what force is demonstrated with like charges attraction repulsion
repulsion
a selenium is a __ conductor insulator semi conductor
semi conductor
the imbalance that occurs during blank causes an object to gain or lose electron static electricity lightning charging an object accumulating a charge
static electricity
a grounding conductor helps a prevent a shock hazard in the event that an ungrounded or hot conductor comes in contact with the case or frame of an appliance true false
true
earth contains magnetic poles true false
true
variable resistors can be obtained in different case styles and power ratings a. true b. false
true
what is another term for electro motive force amperage ohmage voltage wattage
voltage
what can be adjusted to provide any value of voltage between 12 and 0 volts multi turn variable resistor volt meter rheostat wiper
wiper
what is the max number of valance electrons in an atom 4 6 8 12
8
an electric motor is running on 120v 2 amps how many ohms 60 118 122 240
60
any time an electric current flows what component is a magnetic field created around for the conductor conductor semi conductor molecule electron
conductor
what is the flow of electrons of a conductive substance current volts watts cycle
current
during normal operation of a typical 120v appliance circuit current flows through the hot grounding and neutral conductors tru false
false
what type of resistor can only have 1 ohmic value fixed variable middle film composition
fixed
the static charge that occurs during spray painting helps to produce a uniform finish True false
true
the value of a resistor can often be determined by the color code tru false
true
there are 2 theories about current flow, electron flow theory and conventional flow theory tru false
true
using ohms law chart power can be found when voltage and current are known E=IR tru false
true
using ohms law chart resistance can be found when power and current are known R=p/I squared tru false
true
the static charge sometimes used during spray painting is an example of a __ static charge nuisance useful
useful
engineering schematic use symbols to represent a resistor t f
f
sometimes static ncharges are a nuisance t f
t
squiggly with an arrow is a symbol for fixed resistor t f
f
the dry copy machine does not depend on static electricity tru false
false
voltage flow through an electric circuit like water flows through a pipe true false
false
a drag chain is attached to a frame of a vehicle and the other end drags the ground t f
t
if the leads of a 17 volt battery were connected between different points b c would indicate 16v true false
false
if the opposite pole of 2 magnets are brought close to each other they repel each other tru false
false
in electrical schematics the symbol used to rep a resistor is standard tru false
false
square horshoe magnet contains magnetic wire around the center true false
false
when a resistor has a power rating of 1/2 watt and the amount of heat being dissipated is 1 watt, the resistor will not be damged true false
false
a circuit has a resistance of 20ohms and 6amps how many volts three and a third fourteen 26 120
120
current flows positive to neg t f
f
in a speaker when the electromagnet has a south polarity it is repelled from the permanent magnet t f
f
in a static charge if an object lacks electrons then it has a negative charge t f
f
matter can only exist in two states solid or liquid t f
f
most lightning discharges associated with cloud occur between the cloud and the ground t f
f
one btu equals 1.36w t f
f
static electricity is a current t f
f
the north pole on the compass points to the south geographic pole t f
f
using the ohms law chart current can be found when power and volts are known rep by I=PE t f
f
a rectangle with an arrow is a symbol of variable resistor t f
t
ceramic magnetic materials mixed with liquids can be used to make magnetic ink which is used on checks t f
t
by connecting resistors of the proper value almost any voltage desired can be obtained tru false
true
copy machines operate on the principal of static electricity tru false
true
industry often uses electromagnets to pick up metal objects often call round horshoe magnet tru false
true
person can prevent a painful shock by holding a coin in one hand and touching the coin to a grounded surface tru false
true
the grounding prong of a plug should never be cut off or bypass true false
true
joules def as 1 newton meter t f
t