Metals and Alloys: Properties, Uses, and Applications
Depending on their origin, we distinguish natural materials like silk or quartz, synthetic, such as concrete or glass, and auxiliaries, such as polishes, lubricants, insecticides, and others.
Ferrous Metals
Ferrous materials are those whose main component is iron, associated with other substances, both metallic and non-metallic.
Iron Minerals
- Magnetite: Dark, almost black, and an excellent iron ore, with 60-70% iron.
- Red Hematite: Compact masses of red, containing 40-60% iron.
- Siderite: Yellowing, some
Understanding Electricity Generation and Electric Fields
Methods of Generating Electricity
By Rubbing:
Rubbing a glass rod against a wool cloth causes electrons (e-) to transfer from the glass to the wool. The wool cloth becomes negatively charged, and the glass rod becomes positively charged. This is known as static electricity.
Piezoelectric Effect:
When piezoelectric materials, such as quartz, are subjected to pressure (P) between two opposite sides, electric charges appear on these surfaces. This principle is used in knock sensors. The process is reversible.
Read MoreUnderstanding Physical Quantities and Measurement Principles
Understanding Physical Quantities and Measurement
Define the term ‘physical quantities’.
Physical quantities are all those properties or qualities of matter, energy, and measurable space.
Identify which of the following are physical quantities:
Density, Volume, Length, Temperature, Area, Pressure, Time.
Note: Ira, Patriotism, Beauty, Citizenship, Feeling, and Love are not physical quantities.
What is Measurement?
Measurement is the process of comparing two magnitudes of the same nature, using one as the
Read MoreConstruction Staking: Tools, Techniques, and Best Practices
Introduction to Construction Staking
Staking, in general, is the process of determining and marking the position an element should occupy in the field.
In the field of construction, this refers to marking and drawing on the work itself, at a natural scale, any building element defined in the project.
Instruments and Supplies for Construction Staking
These tools are grouped according to their function:
- Length measurement: measuring tape
- Verification of verticality: plumb bob
- Verification of horizontality:
Engineering Materials: Properties, Types, and Applications
Classification of Engineering Materials
Ferrous Materials
These are materials that contain iron as their primary constituent.
Examples: Cast iron, steel, wrought iron.
Characteristics: High strength, magnetic properties, prone to corrosion unless treated (e.g., stainless steel).
Non-Ferrous Materials
These materials do not contain iron as a major component.
Examples: Aluminum, copper, titanium, brass, bronze.
Characteristics: Lightweight, corrosion-resistant, good electrical conductivity.
Alloys
A mixture
Read MoreRelays, Circuits, and Electromagnetism Explained
Relays: How They Work
A relay consists of two primary mechanisms:
- An electromagnet that can be controlled by low-intensity current.
- Contacts that open and close due to the electromagnet’s action.
Low-intensity current is used to control a larger current. A relay is composed of the electromagnet (coil and core), contacts (open and closed), springs, coil connections, and a common terminal.
Relay Operation Example
Consider a system with two lamps, two batteries, and two relays:
- When electricity is supplied