BTEB Diploma in Engineering Semester Final Examinations key terms

Internal resistance force developed per unit area inside a material when it is subjected to an external load. It is normally expressed in newtons per square millimetre or megapascals.

The ratio of change in length of a member to its original length when a load is applied. It is a dimensionless quantity used to describe deformation.

The ratio of direct tensile stress to the corresponding longitudinal strain within the elastic limit of a material. It measures how stiff a material is.

The ratio of the ultimate or yield strength of a material to the working stress actually permitted in a design. It accounts for uncertainty in loads and material quality.

The algebraic sum of the moments of all forces acting on one side of a section of a beam, about that section. It produces bending and normal stresses across the depth.

The algebraic sum of all vertical forces acting on one side of a section of a beam. It tends to slide one part of the member past the adjacent part.

A workability test for fresh concrete in which a standard cone is filled and lifted, and the vertical settlement of the concrete is measured. Higher slump indicates wetter, more workable mix.

The mass of water divided by the mass of cement in a concrete mix. Lower values increase strength and durability but reduce workability.

The process of removing entrapped air from fresh concrete or soil by vibration or rolling, increasing its density. It improves strength and reduces permeability.

The statement that current through a conductor is directly proportional to the potential difference across it, provided temperature remains constant. The constant of proportionality is resistance.

Two circuit rules: the current law states that currents entering a node equal those leaving; the voltage law states that the sum of voltages around a closed loop is zero.

The cosine of the phase angle between voltage and current in an alternating-current circuit. It equals real power divided by apparent power and indicates how effectively power is used.

A static electromagnetic device that transfers electrical energy between two circuits at different voltage levels through mutual induction, without changing frequency or the total power ideally.

A sequence of processes that returns a working fluid to its initial state, allowing continuous conversion of heat to work. Examples include the Otto and Rankine cycles.

A thermodynamic property equal to internal energy plus the product of pressure and volume. It represents the total heat content available in a flowing fluid.

A closed pressure vessel in which water is heated to produce steam at a pressure above atmospheric. The steam is used for power generation or process heating.

The total permissible variation in a dimension, being the difference between the upper and lower limits of size. It defines how much a part may deviate from nominal size.

The relationship between the sizes of a hole and a shaft that determines the tightness or looseness of their assembly. Common types are clearance, interference and transition fits.

A gauge having two working ends, 'go' and 'not go', used to check whether a workpiece dimension lies within its specified limits without measuring an actual value.

A database design process that organises relations to reduce redundancy and avoid insertion, update and deletion anomalies, usually through successive normal forms such as 1NF, 2NF and 3NF.

A column or minimal set of columns whose values uniquely identify each row of a table and which cannot be null. It enforces entity integrity.

A diagram that uses standard symbols such as ovals, rectangles and diamonds to represent the sequence of steps, decisions and input-output of an algorithm or process.

In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides. It is used to find unknown lengths and distances.

A ratio of two sides of a right-angled triangle, such as sine, cosine or tangent of an acute angle. These ratios relate angles to side lengths.

A scalar is a quantity having magnitude only, such as mass or temperature; a vector has both magnitude and direction, such as force or velocity.

The idea that one mole of any substance contains Avogadro's number of particles and has a mass in grams equal to its relative molecular mass. It links mass to particle count.

The number of moles of solute dissolved in one litre of solution. It expresses solution concentration and is denoted by the symbol M.

A logarithmic scale from 0 to 14 that expresses the acidity or alkalinity of an aqueous solution as the negative logarithm of hydrogen ion concentration. A value of 7 is neutral.

A method of representing a three-dimensional object by projecting its views onto two or more mutually perpendicular planes, usually giving front, top and side views.

A pictorial drawing in which the three principal axes are inclined at equal angles and lengths are drawn to the same scale along all three axes, giving a single three-dimensional picture.

A projection convention in which the object is placed between the observer and the plane of projection, so the view appears on the far side of the object.

The smallest measurement that an instrument can read reliably. For a vernier calliper it is the difference between one main-scale division and one vernier-scale division.

A formal written communication between organisations or between an organisation and an individual, following a standard structure of heading, reference, body, complimentary close and signature.

The structured preparation of a factual document containing an introduction, methodology, findings, conclusions and recommendations, intended to inform a specific reader for a specific purpose.

A written summary of a person's education, work experience, skills and references, prepared for job applications. It is usually one to three pages long.

The level of sales at which total revenue equals total cost, so the business makes neither profit nor loss. It is found by dividing fixed cost by contribution per unit.

An expense that does not change with the volume of output within a relevant range, such as rent or insurance. It must be paid even when production is zero.

A preliminary investigation that assesses whether a proposed project is technically possible, financially viable and socially acceptable before major resources are committed.

A supervised period of practical work in an industry or workshop that lets a student apply classroom knowledge to real tasks and develop workplace skills and habits.