delmar midterm sections 4 & 5
What is the RMS value of an AC voltage that has a 480 V peak?
339.46V
Lithium cells can have voltages that range from 1.9 volts to 3.6 volts.
True
Each complete waveform of 360° is called a _____.
cycle
The number of cycles completed in 1 second is called a _____.
frequency
What kind of copper atoms become ions during electroplating?
pure
The no-load voltage of a cell is greater than the normal load voltage because of the internal _____ of the cell.
resistance
A line that indicates both magnitude and direction is a _____.
vector
What is the terminal voltage of a nicad battery containing six cells?
7.2volts
A right angle is an angle of _____.
90°
The ________ function is equal to the opposite side divided by the adjacent side.
Tangent
If current is flowing in a circuit containing an inductor and the power switch is opened, the magnetic field surrounding the inductor collapses and induces voltage into the inductor, resulting in a voltage spike.
True
In electroplating, the electrolyte solution must contain ions of the metal to be plated.
True
The amount of air pressure greatly influences the voltage required to reach ionization potential.
True
The amount of voltage induced into a conductor depends on the turns of wire, the strength of the magnetic field, and the speed of the cutting action.
True
When a voltage is induced in a coil and there is a complete circuit, current flows through the coil
True
When batteries or cells are connected in series, their voltages add, and their current capacities remain the same.
True
Who discovered and named X-rays?
Wilhelm Roentgen
Several cells connected together that produce voltage are called a _____.
battery
The important factors concerning _____________ are a conductor, a magnetic field, and relative motion.
electromagnetic induction
When a conductor cuts magnetic lines of force, a voltage is induced into the conductor. This principle is called _____.
electromagnetic induction
An ion is an atom that has had a(n) _____ added or removed.
electron
What is the most important factor in ionization of a gas?
electron impact
What is the process of depositing atoms of one type of metal onto another using electricity?
electroplating
A buildup in the atmosphere of charged particles that are not strong enough to cause lightning will often produce a continuous discharge of light around objects, often referred to as the aurora borealis.
false
An alkaline-manganese C cell size has 4.9 watt-hours per cubic inch.
false
As the atmospheric pressure increases, the amount of voltage required to reach ionization potential _____.
increases
What causes the aurora borealis?
ionization of gas
What term refers to the amount of voltage an electron must possess to cause ionization?
ionization potential
What is a coil wound on a magnetic core material, such as silicon steel?
iron-core inductor
A horizontal line is indicated by how many degrees?
0
A coil has an inductance of 3 H and a wire resistance of 15 Ω. How long will it take for the current to reach its full value?
1.0 sec
A right triangle has one side of 5 and another side of 4 (neither side is the hypotenuse). What is the angle adjacent to the side that is 5?
38.66
Gas-filled tubes operate with ____________ atmospheric pressure inside the tube.
less than normal
When an electron strikes a gas molecule that does not have enough energy to release other electrons, the molecule will emit _________ to rid itself of the excess energy.
light
Which atom contains two valence electrons and is considered to be a metal?
magnesium
What is the approximate sum of the following two vectors: magnitude 20 at 30° and magnitude 10 at 60°?
magnitude 29 at 40°
What is one device used for spike suppression in either direct or alternating current circuits?
metal oxide varistor
Which of the following is also called an Edison battery?
nickel iron
Which of the following is a secondary cell?
nickel-cadmium
Once the sine, cosine, or tangent of the angle has been determined, the angle can be found by using a(n) ______________.
scientifc calculator
The function that is equal to the opposite divided by the hypotenuse is the _____.
sine
_____________ waves are so named because the voltage at any point along the waveform is equal to the maximum, or peak, value multiplied by the sine angle of rotation.
sine
When a high-impedance voltmeter is connected across two coins, a __________ is produced.
small voltage
Lead-acid batteries use an electrolyte containing _____.
sulfuric acid
When using the left-hand generator rule, the thumb points to the direction of _____.
thrust
Using Fleming's left-hand generator rule, which points to the movement of the conductor?
thumb
Vectors must be added using _____ addition.
vector
In a DC circuit, the product of volts times the amperes is called the _____ power.
True
Most of the electric power in the world is produced by alternators.
True
In its natural form, _______________ is in the form of blue crystals.
copper sulfate
Plating copper onto iron often involves a poisonous solid called _____.
cuprous cyanide
Direct current is used as the power source in electroplating.
True
One factor that determines inductance is how far the windings are separated from each other.
True
The farther apart electromotive metals are on the list of ability to accept electrons, the higher the voltage the cell develops
True
When a resistive load is suddenly connected to a source of DC, the current instantly rises to its maximum value.
True
Piezoelectricity refers to electricity produced by some materials when they are subjected to _____.
pressure
What type of cell cannot be recharged?
primary
A rectangle is a parallelogram with __________ -degree angles.
90
The operating principles of the cathode-ray tube were discovered by _____.
JJ Thomson
An induced voltage opposes the motion that causes it according to _____.
Lenz's Law
In a right triangle, the sum of the squares of two sides is equal to the square of the hypotenuse. This was discovered by a Greek named _____.
Pythagoras
Fleming's left-hand generator 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.
True
An inductor is basically an electromagnet that changes its polarity at regular intervals.
True
Connecting the batteries or cells in parallel has the effect of increasing the area of the plates.
True
A(n) _____________ battery is a lead-acid battery that does not spill sulfate or degrade like the common flooded cell battery.
absorbed glass mat (agm)
The word _____ is often used in reference to a single cell.
battery
What kind of cable is less affected by the skin effect?
braided
Which are commonly used in cameras, watches, hearing aids, and handheld calculators?
button cells
The LeClanché cell is also known as a(n) _____ cell.
carbon-zinc
When electroplating, the object to be plated must always be connected to the _________.
cathode
The amount of voltage produced by an individual _____ is determined by the materials from which it is made.
cell
Using Fleming's left-hand generator rule, which shows the direction of the current induced into the armature?
center finger
When current flows through a(n) ___________, a magnetic field is created around it.
conductor
What is the maximum current (amperes) that should be applied when charging an 80-ampere-hour battery?
eight (8)
What is the process of separating elements electrically?
electrolysis
Atmosphere pressure is 24 pounds per square inch (PSI) at sea level.
false
Atoms that have gained extra electrons are known as positive ions.
false
Flux lines pass through a core material with a low permeability better than through a material with a high permeability.
false
In practice, it is often desirable to move the conductor instead of the magnet.
false
Metal ions are always negatively charged in electroplating.
false
Silver-zinc is a primary cell containing a zinc negative plate and a silver oxide positive plate.
false
The silver-zinc cell develops a voltage of 1.35 volts.
false
Exponential curves are always divided into _____ time constants.
five (5)
The direction of induced current can be determined by using _____'s left-hand generator rule.
fleming
X-rays result when cathode rays strike a _____.
gas
Which of the following metals would not accept electrons more easily than the others listed?
gold
A device used for measuring the specific gravity of a cell is called a _____.
hydrometer
In a right triangle, the longest side is called the _____.
hypotenuse
Using the Pythagorean theorem, what is represented as "c"?
hypotenuse
In this diagram of a resistive circuit, the switch is currently open. What happens to the current when the switch is closed?
it instantly rises to a vlaue of 2amperes
A way of determining the relationships of the motion of the conductor, the magnetic field direction, and the direction of the induced current is by using the _____.
left hand generator rule
The magnetic quantity Weber (Wb) is equal to 100,000,000 lines of flux. If a conductor cuts through one Weber per second, then a voltage of _____ volt(s) is induced into the conductor.
one
If a conductor is moved upward, the polarity of induced voltage is reversed and the current flows in the _______________ direction.
opposite
Which memory aid will help you remember the trigonometric function relationships?
oscar had a heap of apples
During electrolysis, electrons are removed from what kind of ions and returned to aluminum ions?
oxygen
One method of adding two vectors that originate at the same point is the _____ method.
parallelogram
Multiplying like signs such as, - x -, produces what kind of product?
positive
What type of load contains pure resistance?
resistive
___________ loads are loads characterized by the facts that they produce heat and the current and voltage are in phase with each other.
resistive
If a voltage is being induced into a conductor by electromagnetic induction, reversing the direction of motion of the conductor will _____.
reverse the polarity of the induced voltage