Gas - Unit L Flashcards
The smallest unit of the element that still possesses the properties of that element is referred to as:
An atom.
The center of an atom is called the:
Nucleus.
List the three subatomic particles that make up the atom.
Electron.
Neutron.
Proton[]]
Describe the charges of the three subatomic particles that make up the atom.
Electron (Negative)
Neutron (Neutral)[][]
Proton (Positive)[][]]
What is the physical relationship between the electron and the proton?
Electron revolve around the nucleus.
Electrons 3 times larger than protons.
Electrons 1840 times lighter than protons.
Name three possible electrical charges that an atom may possess.
Negative.
Neutral[][]
Positive[]]
What numerical relationship must exist between the electrons and the protons to give an atom a negative charge?
More electrons than protons.
Force fields surrounding the charges object are known as:
Electrostatic fields.
An itom with either a positive or negative charge is called an:
Ion.
What is the name of the orbital path the electron follows around the atom?
Orbital shell.
What is the maximum number of shells an atom will contain?
Seven.
What is the name of the outer shell of an atom?
Valence shell.
Describe in one word how energy is shard between the electrons in the outer valence shell.
Equally.
Which valence electrons would have the most energy?
Those of an atom with only one valence electron.
Name three metals considered to be the best conductors and why.
Copper.
Gold[][]]
Silver[][]
Atoms that contain only one valence electron.
Name three materials that are good insulators and why.
Glass.
Rubber.
Wood[]]
Materials which contain five or more valence electrons which are difficult to free.
Name three materials that are good semiconductors and why.
Germanium.
Selenium[][]]
Silicon[][][][][]
Medium stability, conduct better than insulators, not as good as conductors.
How many valence electrons do the following materials contain?
Conductors?
Semiconductors?
Insulators[][][][][][]]?
1 or 2.
4[][][][]]
5 or more.
True or False?
If two metals are joined and the junction is heated, a voltage difference will exist between the two metals.
True.
What is the name of the device where two metals are joined and the junction is heated?
Thermocouple.
True or False?
A conductor moving through a magnetic field produces electrical current flow (electricity).
True.
True or False?
A current moving through a conductor causes a magnetic field.
True.
True or False?
Batteries change chemical energy into electrical energy.
True.
True or False?
Certain types of crystals subjected to high pressures can cause high voltages, resulting in sparks.
True.
True or False?
A photoelectric cell will conduct electricity when it is subjected to light.
True.
When electrons move in the same direction, they produce a/an:
Electric current.
The speed of the impulse with which electrons move each other along a conductor is:
Speed of light - 186,000 miles/second.
True or False?
An open circuit conducts electricity while it is building up a static charge.
True.
True or False?
Current flows as long as voltage is applied across a closed circuit.
True.
Electricity is used to produce three important effects. These are:
Heat.
Light[]
Magnetism.
A good conductor of electricity is _______ wire.
Copper.
Which type of light bulb produces the most heat, incadescent or fluorescent?
Incadescent.
A current flowing around a wire will cause a _________ field to form around the wire.
Magnetic.
True or False?
Electrical charges are surround by electrical as well as magnetic force fields.
True.
True or False?
Magnetic molecules are so named because the magnetic effects of their electrons do not cancel each other out, but add together.
True.
True or False?
Magnetic materials are attracted or repelled by magnets and become magnets when a magnetic force is applied to them.
True.
True or False?
Like poles repel, unlike poles attract.
True.
True or False?
Magnetic lines of force are invisible, but you see their effects by the way iron filings surrounding a magnet line up on paper.
True.
Current flow in a wire causes a ___________ around the wire.
Magnetic field.
A coil of wire used to make a strong magnetic field is called a:
Solenoid.
The magnetic field in a coil can be made even stronger by inserting a core made of:
Soft iron.
The direction of magnetic lines of force around a wire, as well as the N pole of an electromagnet can be found by the ______ rule.
Left-hand.
An electric circuit consists of a power source, a switch, connecting wires, and a:
Load.
The switch proves a means of _____ or _______ a complete path.
Making or Breaking.
A power source is often called a _____ source because electromotive force of emf is measured in volts.
Voltage.
The _____ of voltage in the source determines how much current will flow, while the _____ of voltage in the source determines the direction of current flow.
Amount / Polarity.
The ____ is a device that uses the energy of a power source to perform some useful work.
Load.
True or False?
Electron current flows if there are electrical charges and a complete circuit between them.
True.
True or False?
Electrical charges might be called potential or voltage.
True.
True or False?
Electron current always flows from high to low voltage.
False.
True or False?
A volt is a potential difference caused by a coulomb of charge.
True.
True or False?
A coloumb per second is 1 ampere.
True.
True or False?
If the source is 1 volt and the load is 1 ohm, the current will be 1 ampere.
True.
Choose Ohm’s Law.
A. I = E x R.
B. R = E x I.
C. E = I x R.
D. R = I / E[]
C. E = I X R.
In AC circuits what alternates is the:
A. Power.
B. Voltage only.
C. Current only[]
D. Current and voltage.
D. Current and voltage.
Electromagnetic energy is produced by:
A. AC circuits.
B. DC circuits.
C. Power circuits.
D. High voltage circuits.
A. AC circuits.
The minimum power losses occur in circuits with:
A. Large wire.
B. High voltage and low current.
C. High current and low voltage[]
D. High resistance[][][][][][][][][][][][][]
B. High voltage and low current.
What must be the same for two circuits to have the same power level?
A. The voltage and current.
B. The sum of the voltage and current.
C. The product of voltage and current[]]
D. The ratio of voltage to current[][][][][]]
C. The product of voltage and current.
AC generators are also called:
A. Power jacks.
B. AC batteries.
C. Armatures[][][]
D. Alternators[][]
D. Alternators.
AC generators produce power by:
A. Switching terminals on a battery.
B. Rotating a coil in a magnetic field.
C. Making steam near a waterfall[][][]
D. Installing a transformer[][][][][][][][][]]
B. Rotating a coil in a magnetic field.
The graph plot of a DC Voltage with time would look like a/an:
A. Straight line.
B. Ellipse[][][][][]]
C. Parabola[][][][]
D. Sine wave[][]]
A. Straight line.
The graph plot of an AC voltage with time would look like a/an:
A. Straight line.
B. Ellipse[][][][][]]
C. Parabola[][][]]
D. Sine wave[][]
D. Sine wave.
A complete cycle is equal to how many degrees of rotation?
A. 90°
B. 180°
C. 270°
D. 360°
D. 360°
If two circuits always pass through a 90 at the same time, they are:
A. In phase.
B. 90° out of phase.
C. 180° out of phase.
D. 270° out of phase.
A. In phase.
List seven factors that affect the severity of an electric shock.
A. AC or DC type voltage
B. Amount of current[][][][]]
C. Area of contact[][][][][][][]
D. Moistness of skin[][][][][]]
E. Path through body[][][][]]
F. Time energized[][][][][][][]]
G. Voltage valve[][][][][][][][][]]
What is the most lethal current range for an electric shock?
50 to 200 mA.
What is the first thing that you should do when you see someone recieving an electric shock?
Remove the electricity, dont touch the victim first.
At what point is it acceptable to stop attempted resuscitation of a victim of elctrocution?
When advised by medical authority.
Is current or voltage the real measure of an electric shock’s intensity?
Current.
A coil with a strong magnetic field produces forces like a:
Magnet.