Ch 1 Flashcards
The Law of Attraction and Repulsion of magnets states:
Like poles repel each other and unlike poles attract each other
This is the result of the atomic bonding of two or more atoms
Compounds
What would you use to protect the electrical equipment in a building?
Surge protectors
What will a magnet align itself with if it is hung freely from a piece of string?
Earth’s magnetic field
What keeps electrons from breaking out of their orbit around the nucleus?
Law of electrical charges
When a magnet is hung freely, what do you call the end that is pointing north?
north-seeking pole
What do you call a switch that uses an electromagnetic field to open or close a set of contacts?
Electromagnetic Relay
When atoms of elements combine they produce _____
Compounds
Some crystalline materials produce a small electrical voltage when bending or twisting pressure is applied to them, what is the effect?
Pressure (Piezoelectricity)
Illumination is produced when a source of energy strikes phosphorus materials
Phosphorescent illumination
The conductor that rotates between the stationary magnetic field poles of the stator is called what?
Rotor or armature
What is the maximum let-go threshold for women and men?
10mA and 16 mA
What is the only naturally occurring magnet?
Lodestone
When energy is applied to valence electrons, it is divided evenly among them, how does that affect them?
Fewer valence electrons for a given amount of energy means each valence electron receives more available energy.
What causes the armature of a dc motor to rotate?
The repelling forces of similar magnetic polarities and the attracting force of opposing polarities.
How many shells are around the nucleus of an atom where electrons orbit?
7
This is the process where heat is applied to dissimilar metals that are joined together to produce about 5 to 30 thousandths of a volt.
Thermoelectric effect
(T/F) A magnet will affect a compass?
True
What forces the rotor to rotate in a generator?
Prime Mover
What materials make up permanent and temporary magnets?
Hard Steel & Soft Iron
What do you call the stationary magnetic field around a dc motor?
Stator
Compounds can change the _____ _______ of the individual atoms
electrical characteristics
What does a clamp-on AC ammeter detect?
The rising and falling and falling of the magnetic field around the conductor.
What dictates the distance an arc can jump?
Voltage & Dielectric