Tech

Orthographic drawings

An orthographic drawing is a technical drawing that shows an object from different directions using separate, flat views. The three main views include the front view, top view, and side view, maintaining alignment with dimensions of length, width, and height.

Properties of various construction materials

Material properties describe how materials behave under different conditions such as forces or temperatures. Important properties include strength, hardness, toughness, and flexibility, guiding engineers in material selection for various applications.

Pascal's principle

Pascal's principle states that pressure applied to an enclosed liquid is transmitted equally throughout the liquid. This principle allows small input forces on one piston to produce larger output forces on another piston.

Gears

Gears are toothed wheels that transfer rotational movement and force between shafts. They can change speed, direction, and turning force, with important terms including driver gear, driven gear, and gear ratio.

Ratchet and pawl

A ratchet and pawl is a mechanism allowing movement in one direction while preventing reversal. It consists of a toothed ratchet wheel and a pawl that engages with the teeth to stop backward movement.

Hydraulic press

A hydraulic press uses pressure transmitted through liquid to exert large forces, allowing materials to be pressed or shaped. It operates through Pascal's principle, using an input piston and a larger output piston.

Hydraulic jack

A hydraulic jack raises heavy loads using liquid pressure transmitted from a small input piston to a larger output piston. It includes key components such as the handle, pump piston, and release valve.

Pneumatic system

A pneumatic system operates using compressed air to transmit energy and control machinery. Major components include a compressor, air reservoir, valves, and actuators converting air pressure into mechanical movement.

Preserving materials

Preserving materials protects them from damage due to environmental factors such as moisture and sunlight. Common methods include painting, varnishing, and sealing to extend the useful life of materials.

Load and force

A force is a push or pull affecting an object's motion or shape, while load refers to the force a structure must support. Types of forces include tension, compression, and shear, with moments calculated using force times perpendicular distance.

Electrical/electronic system

An electrical system harnesses electrical energy to perform tasks, while an electronic system processes electrical signals. Both consist of inputs, processes, and outputs, involving components like cells, switches, and resistors.

Types of lines

Technical drawings employ various line types to represent object geometry and dimensions clearly. Line types include visible lines, hidden lines, dimension lines, and center lines, each serving specific purposes.

Pulleys

A pulley is a wheel with a groove that guides ropes or cables and can change force direction or reduce input force when arranged correctly. Types include fixed, movable, and compound pulleys.

Plastics

Plastics are polymers known for being lightweight and moldable, allowing for diverse applications. They can possess various properties like water resistance and flexibility, influencing their suitability for specific uses.

Food preservation methods

Food preservation slows spoilage, maintaining safety and usability through methods like refrigeration and drying. Each method works by controlling factors like moisture or temperature to inhibit microbial growth.

Plastics: meaning, type and properties

Plastics can be thermoplastics or thermosetting plastics, with thermoplastics able to be reshaped upon heating. Their properties include flexibility and strength, influencing their practical applications.

Advantages of recycling plastics

Plastic recycling reduces landfill waste and conserves raw materials while saving energy in production. It can create jobs in collection and processing but faces challenges such as contamination affecting recyclability.

Hydraulics and pneumatics system

Hydraulic systems use liquids to transmit energy, while pneumatic systems use compressed gases. Both systems feature distinct characteristics regarding force, movement, and fluid leakage.

Mechanical advantage of a system

Mechanical advantage (MA) indicates how much a machine amplifies input force compared to output force. It is calculated as the ratio of output force to input force.

System diagram of a hydraulic jack

A system diagram illustrates key components of a hydraulic jack, including input, pump, hydraulic fluid, and output ram, showing their interactions to accomplish lifting tasks.

Electric/electronic components (circuit diagram)

A circuit diagram represents electrical paths, using standard symbols for components, allowing for easier understanding of circuit function. Components include cells, switches, and light bulbs, each serving specific roles.

Preserving metals

Preserving metals involves protection from corrosion and damage to extend their lifespan. Methods include painting, galvanizing, and applying protective coatings to resist environmental degradation.

Ohm's law

Ohm's law defines the relationship between voltage, current, and resistance in a conductor. It states that current is proportional to voltage and inversely proportional to resistance, expressed as V=I×R.

Logic gate

A logic gate processes binary inputs to produce a binary output based on logical operations. Common types include AND, OR, and NOT gates, each defined by specific rules of input-output relationships.

Resistor colour code

The resistor colour code conveys the resistance value and tolerance of a resistor through a series of coloured bands. In a four-band code, the first two bands define digits, the third denotes the multiplier, and the fourth indicates tolerance.