VCE Systems Engineering flashcards
VCE Systems Engineering · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Mechanical advantage
- The ratio of load force overcome to effort force applied by a machine. It is calculated as load divided by effort and has no unit.
- Velocity ratio
- The ratio of the distance moved by the effort to the distance moved by the load in the same time. It describes the machine's geometry, not friction.
- Class 2 lever
- A lever where the load sits between the fulcrum and the effort, such as a wheelbarrow. It always gives mechanical advantage greater than one.
- Torque
- The turning effect of a force about a pivot, equal to force multiplied by perpendicular distance from the pivot, measured in newton metres.
- Gear ratio
- The number of teeth on the driven gear divided by the number on the driver gear. Ratios above one reduce output speed and increase output torque.
- Static equilibrium
- A condition where the sum of all forces and the sum of all moments about any point are both zero, so the body does not accelerate.
- Young's modulus
- The ratio of tensile stress to tensile strain within the elastic region of a material. A higher value indicates a stiffer material.
- Friction coefficient
- The ratio of friction force to normal force between two surfaces. Static values are larger than kinetic values for the same pair.
- Ohm's law
- The relationship stating that voltage across a conductor equals current through it multiplied by resistance, valid for ohmic components at constant temperature.
- Electrical power
- The rate of energy transfer in a circuit, calculated as voltage multiplied by current, or current squared multiplied by resistance.
- Series circuit
- A circuit where components form a single path. The same current flows through all components and the total resistance is their sum.
- Parallel circuit
- A circuit where components connect across the same two nodes. Voltage is common to each branch and branch currents add together.
- AND gate
- A digital logic gate whose output is high only when every input is high. Its truth table has one high output row for two inputs.
- Truth table
- A table listing every possible combination of logic inputs alongside the resulting output, with two to the power n rows.
- Relay
- An electromagnetic switch where a low-power coil operates contacts in a separate circuit, providing isolation and allowing a small signal to control a large load.
- Thermistor
- A temperature-sensitive resistor whose resistance changes predictably with heat. Negative temperature coefficient types decrease resistance as temperature rises.
- Design brief
- A short statement defining the problem, the client, the purpose of the product, and the constraints and criteria the solution must satisfy.
- Open system
- A system that exchanges energy, mass or information with its surroundings across a defined boundary, in contrast to a closed system.
- Function block diagram
- A diagram breaking a system into sub-functions drawn as blocks, linked by arrows showing the flow of energy, material or information.
- Critical path
- The longest sequence of dependent tasks in a project schedule. It determines the minimum possible project duration and has zero slack.
- Orthogonal projection
- A drawing method showing separate front, top and side views projected at right angles, arranged according to first-angle or third-angle convention.
- Design specification
- A list of measurable requirements and limits a product must meet, used later as the checklist for evaluating the completed design.
- Anthropometric data
- Body measurement statistics such as reach, height and grip span, used to size products so a large proportion of users can operate them.
- Isometric drawing
- A pictorial drawing with three axes spaced 120 degrees apart, showing height, width and depth without perspective convergence.
- Open-loop control
- A control system that performs a set action without measuring the output, so it cannot correct for disturbance or error.
- Closed-loop control
- A control system that senses the actual output, compares it with the setpoint, and adjusts the actuator to reduce the error.
- Proportional control
- A control action where the output magnitude is directly proportional to the size of the error, leaving a steady-state offset in many systems.
- Hysteresis dead band
- A deliberate gap between switch-on and switch-off thresholds that stops an output rapidly toggling when a sensor signal hovers near one value.
- Flowchart decision symbol
- A diamond shape in a flowchart representing a yes-or-no test that splits the program into two alternative paths.
- Pneumatic actuator
- A device converting compressed air pressure into linear or rotary motion, with force equal to pressure multiplied by piston area.
- Quality control
- The inspection and testing of finished items against tolerance limits and specifications to detect and reject non-conforming product.
- Hierarchy of control
- A ranked order of risk treatments: eliminate the hazard, substitute, engineer controls, administrative controls, then personal protective equipment last.