Basic Electricity I Flashcards
What is an element?
A substance that cannot be reduced to a simpler form by chemical means.
What is a compound?
A chemical combination of two or more elements.
What is a molecule?
The smallest particle of matter that can exist and still retain its identity.
What are the three subatomic particles in an atom?
Protons, neutrons, and electrons.
What is the energy level of an electron defined as?
The amount of energy an electron requires to stay in an orbit.
What is the formula for electron capacity?
Electron capacity = 2n²
n represents the energy level in question.
What is valence?
The number o chemical bonds an atom can form.
What are valence electrons?
Electrons that can participate in chemical bonds with other atoms.
What is ionization?
The process by which an atom loses or gains electrons.
When an atom loses electrons it becomes positively charged. What is this positively charged atom called?
A positive ion or a cation.
When an atom gains electrons it becomes negatively charged. What is this negatively-charged atom called?
A negative ion or an anion.
What are conductors?
Elements such as gold, copper, and silver possess many free electrons and make good conductors.
What are insulators?
Insulators are materials that do not conduct electrical current very well or not at all, such as glass, ceramic, and plastic.
What are semiconductors?
The material properties of semiconductors fall in between conductors and insulators. In their pure state, they are not good at conducting or insulating.
What does the prefix Mega (M) mean?
One million (1,000,000)
What is static electricity?
Electricity where the electrons are at rest rather than in motion.
What is an electrostatic (dielectric) field?
A field of force around a charged body. Represented by lines extending in all directions from the charged body and terminating where there is an equal and opposite charge.
Define ESD
Electrostatic discharge
Define LRU
Line replaceable unit
What is magnetic flux?
The lines of force that make up a magnetic field.
What is reluctance?
The measure of opposition to magnetic lines of force through a material.
What are the two types of magnets?
Natural and artificial
What are the two types of artificial magnets?
Permanent and temporary
What is a permanent magnet?
A magnet which retains its magnetism long after the magnetizing force has been removed.
What is a temporary magnet?
A magnet that quickly loses most of its magnetism when the external magnetizing force is removed.
What are the most common categories of magnet materials made out of?
Alnicos (aluminum-nickel-cobalt), ferrites/ceramics (strontium-iron), neo magnets (neodynium-iron-boron), and samarium-cobalt.
What is the relationship between charged particles and magnetic fields?
The greater the current flow, the greater the magnetic field.
What is the left-hand rule?
If a conductor is grasped in the left hand with the thumb pointing in the direction of current flow, the fingers will be wrapped around the conductor in the same direction as the lines of the magnetic field.
What direction does current flow?
From positive to negative.
How do you increase the strength of the magnetic field of an electromagnet?
You can increase the current or the number of loops in the coil. The type of metal in the core is a factor as well.
What is an electromagnet?
An iron core in a coil of wire loops
What is current?
A measurement of a rate at which a charge flows through some region of space or a conductor.
What is electromotive force?
The push or pressure felt in a conductor that ultimately moves the electrons in a flow. More commonly referred to as voltage. The symbol for emf is E.
