Electrical Engineering: Key Concepts and Applications
Resistivity of Materials
Order the following materials from highest to lowest resistivity:
- Granite and sand (1500-10000 Ωm)
- Limestone (1000-5000 Ωm)
- Modified Granite and sand (100-600 Ωm)
- Peat (5-100 Ωm)
- Clay (50 Ωm)
Premade Busbars Advantages
Premade busbars are flexible and easy to install in large open areas, allowing for future modifications. They are ideal for installations in industrial and commercial areas, offices, laboratories, and all modular facilities subject to frequent changes.
Neutral
Read MoreUnderstanding Electricity: Charges, Conductors, and Coulomb’s Law
The word electricity comes from the Greek word “elektron.” There are two types of electric charges: positive and negative. The origin of electric charge is the atom.
Electric Charge and Atomic Structure
The proton has a positive electric charge, the neutron has no electric charge, and both are located in the nucleus. The electron has a negative electric charge and orbits the nucleus. A neutral atom has an equal number of electrons and protons. If an object’s atoms lose electrons, it will have an excess
Read MoreState Constitutions: Principles, Structures, and Changes
State and Local Government
Constitution:
A written plan that sets up a form of government and establishes its basic governing principles.
Principles in Common:
- Popular Sovereignty
- Limited Government
Differences of Constitution
| U.S. Constitution | State Constitution |
|---|---|
| Short | Lengthy |
| Rarely Amended | Often Amended |
| General in Scope | Specific in Scope |
Early State Constitutions
The Massachusetts Constitution, adopted in 1780, is the oldest written constitution now in force anywhere in the world.
In 1780, Massachusetts set the
Read MoreElectrical Hazards and Safety Measures
Unit 16: Electrical Risk Physical Agents
Electrical Hazards
An electrical accident is defined as receiving a jolt or shock, with or without causing personal damage or injury.
- Direct Contacts (34%): Contacts with parts of the installation normally under strain.
- Indirect Contacts (18%): Contacts with metal parts or elements accidentally energized.
- Arc Burns (48%): Produced by the union of two points at different potentials through a low electrical resistance element.
Factors Influencing the Electrical Effect
- Current
Understanding the Electromagnetic Spectrum and Light Reflection
Electromagnetic Spectrum
The electromagnetic spectrum is the range of all types of electromagnetic radiation. Radiation is energy that travels and spreads out as it goes. The waves that form the electromagnetic spectrum are:
- Radio waves
- Television (TV) and FM radio waves
- Microwaves
- Infrared Radiation
- Visible Radiation
- UV Radiation
- X-Rays
- Gamma rays
Light Sources, Illuminated Bodies, and Propagation
All bodies that are light sources emit their own light.
Illuminated bodies are classified as:
- Opaque bodies
- Translucent
Vibrations and Waves: Physics Problems and Solutions
Vibrations & Waves
1) A wiggle in time is a:
- vibration.
- wave.
- both
- neither
Answer: a
2) A common source of wave motion is a:
- wave pattern.
- harmonic object.
- vibrating object.
- region of variable high & low pressure.
- none of these
Answer: c
3) Like a transverse wave, a longitudinal wave has:
- amplitude, frequency, wavelength, & speed.
- amplitude, frequency, & wavelength.
- amplitude, wavelength, & speed.
- wavelength, speed, & frequency.
- amplitude, frequency, & speed.
Answer: a
4) How many vibrations