texhnology test

Standard opening phrase required for a design brief

"Design and make…"

Design Brief

A short statement written after identifying a problem that outlines what the problem is, why it exists, and what solving it will achieve, without providing the final solution.

Design Specifications

Detailed requirements outlining what a product must do, including necessary features, performance criteria, and specific dimensions.

Design Constraints

The limitations and restrictions imposed on a project, such as available materials, tools, budget, and time limits.

Stiffness (material property)

The ability of a material to resist bending or deformation when placed under a load.

Strength (material property)

The capacity of a material to withstand heavy loads or applied forces without breaking or failing.

Drafting tool set required for isometric drawings

A drawing board, a ruler, and a $30^\circ$ set square.

Representation of circles in 3D isometric projection

Ellipses drawn using a pair of compasses.

Tension

A pulling or stretching force acting on structural members (ties) that tends to elongate them.

Compression

A pushing or squeezing force acting on structural members (struts) that tends to shorten or crush them.

Mine Shaft Headgear

A tall structural framework made of steel or concrete built over a mine shaft to support hoisting pulleys that raise and lower cages and skips.

Mechanical Advantage ($\text{MA}$)

The factor by which a mechanism or machine multiplies an applied input force.

Direction of rotation in meshed gears

Adjacent meshed gears always rotate in opposite directions to one another.

Mechanical effect of an input gear driving a larger output gear

The rotation speed decreases while the output force (torque) increases ($\text{MA} > 1$).

Mechanical effect of a driver gear having more teeth than the output gear

The rotation speed increases, causing the output gear to turn faster.

Series Circuit

An electrical circuit where components are connected sequentially along a single pathway, causing all components to fail if the circuit is broken.

Parallel Circuit

An electrical circuit where components are arranged across separate parallel branches, allowing remaining branches to continue functioning if one fails.

Ohm's Law

The scientific law describing the proportional relationship between Voltage ($V$), Current ($I$), and Resistance ($R$).

Step-up Transformer

A transformer in the national electrical grid that increases voltage (up to $765\,000\,\text{V}$) to minimize energy loss across long transmission lines.

Step-down Transformer

A transformer that decreases transmission voltage (down to $11\,000\,\text{V}$ and eventually to $240\,\text{V}$) for safe consumer and domestic use.

Environmental pollutants released by coal power stations

Carbon dioxide ($\text{CO}<em>2$), which contributes to global warming and climate change, and sulphur dioxide ($\text{SO}</em>2$), which causes acid rain.

Direct Current ($\text{DC}$)

Electric current that flows in one continuous direction, delivered by cells and batteries and capable of battery storage.

Alternating Current ($\text{AC}$)

Electric current that periodically reverses its direction of flow, used for mains power distribution over long distances.