Electrical Principles Module Questions Flashcards
What is the smallest part into which you can divide matter without changing its makeup?
A molecule
Of what are molecules made?
Atoms
What are the 3 basic components of an atom and their electrical charges?
- neutrons (no charge)
neut = neutral
-protons (positive)
pros are positive
-electrons (negative)
What is a stationary electric charge called?
Static electricity
What is a moving electric charge called?
Electric Current
Like charges _________ each other
repel
Unlike charges ________
each other
attract
What is magnetic flux?
The entire magnetic field surrounding a magnet
What are the 3 principles of electromagnetism?
- Moving electrically charged particles create magnetic fields
2.Magnetic fields attract or repel moving charged particles
- Moving magnetic fields near charged particles causes current flow
Higher currents in a conductor cause _________
magnetic fields around the conductor.
Stronger
When a voltage is generated by a magnetic field moving through a conductor, that voltage is known as _______________. The current caused to flow is called ________ current
- Electromotive Force EMF
- Induced
Why does inserting a soft iron core into a solenoid winding greatly strengthen the power of the magnet created?
Iron has higher permeability than air creating a stronger electromagnet
An electromagnet ________
most of its magnetism when it is de-energized.
Loses
4 uses of electromagnetic devices are;
Solenoid Valves
Electric Motors
Scrap Yard Crane Magnets
Electric Brakes
Describe a conductors reaction to current flow?
Conductor exhibits little resistance to flow to the electric current.
Name 3 good conductors;
Gold, Silver, Copper
Describe an insulators reaction to current flow.
Insulator offers high resistance to flow of electric current
Name 3 good insulators
Glass, Mica, Plastics, Ceramic
A semi-conductor is a material that is neither a good ___________ nor a good ___________.
Insulator
Conductor
Name 2 of the most common semi-conductor materials
Silicon
Germanium
What does direct current mean?
Direct Current (DC) always flows in same direction.
Name 2 sources of direct current
DC Generators
Batteries
Name 4 uses of Direct Current
Electronics
DC Motors
Electromagnets
Welding
What does alternating current mean?
Alternating current changes directions regularly and continuously
What is the alternating current wave called?
Sine Wave
Frequency is the measure of the ______________________
of cycles generated per second
When referring to electrical loads, a phase is an instant in time on a sine wave and is measured in
__________ of ________.
degrees of rotation
Name 2 sources of alternating current
Inverter
AC Generator
Voltage can be compared to ____________ in a hydraulic circuit
Pressure
Amperage can be compared to _______________ in a hydraulic circuit
rate of flow
An ampere is a measure of?
current flow
Define Open Circuit
an imcomplete path for current flow
