Engineering
Structures, machines, control and signals. 93 topics, from beginner to advanced.
Browse all 93 Engineering topics →Featured
Visual showcases to start withBeam Bending
A loaded beam sags; stiffness (EI) controls how much. Drag the load position.
Types of Bridges
Beam, arch, suspension and cable-stayed bridges handle forces differently.
The Four-Stroke Engine
Intake, compression, power and exhaust strokes repeat to turn fuel into rotation.
The Jet Engine
Air is compressed, mixed with fuel, burned and expelled to push the aircraft forward.
Rocket Equation
Change in speed depends logarithmically on the ratio of full to empty mass, so rockets are mostly fuel.
Hohmann Transfer Orbit
Two engine burns move a spacecraft between orbits using the least fuel.
Aerodynamic Lift
Lift grows with the square of airspeed and with wing area.
Proportional–Integral–Derivative Control
A PID controller blends present, accumulated and predicted error to steer a system to its target.
Fourier Series: Square Wave
Add odd sine harmonics and a square wave appears — with a Gibbs overshoot at each edge.
Amplitude Modulation
Radio encodes a message in the amplitude of a high-frequency carrier.
The Diode I–V Curve
A diode blocks current in reverse and conducts exponentially once forward voltage passes ~0.6 V.
How Radar Works
A pulse reflects off targets; the delay gives distance and the Doppler shift gives speed.
Popular
Classic topics most learners start withStress–Strain Curve
A material stretches elastically, yields, hardens and finally fractures.
Factor of Safety
Designs include a margin between the expected load and the failure load.
Gear Ratios
Meshing gears trade speed for torque; the ratio is set by the tooth counts.
The Refrigeration Cycle
A refrigerant absorbs heat inside and releases it outside by cycling through evaporation and condensation.
Wind Turbine Power
Available wind power scales with the cube of wind speed, so a bit more wind gives a lot more energy.
Feedback Control Loops
Measure the output, compare it with the goal and correct: thermostats, cruise control and autopilots.
Low-Pass Filters
Pass slow signals, block fast noise. The cutoff frequency sets the boundary.
The Transistor as a Switch
A small base current controls a much larger collector current — the building block of every chip.
How an Elevator Works
A traction elevator balances the cabin with a counterweight to save energy.
How a Solar Cell Works
Photons free electrons across a p–n junction to create current.
The Power Grid
Generators, transmission lines, transformers and distribution deliver power to homes.
The Engineering Design Process
Engineers iterate through define, imagine, plan, build, test and improve.
All 93 Engineering topics
🌱 Beginner
- Beam Bending
- Bending Moment Diagrams
- Stiffness and Deflection
- Young’s Modulus
- Thermal Expansion
- Moment of Inertia of a Beam
- Factor of Safety
- Why Triangles Make Strong Trusses
- Types of Bridges
- Gear Ratios
- Speed Reduction with Gears
- Overdrive Gearing
- Torque, Power and Speed
- Efficiency of Machines
- The Four-Stroke Engine
- The Refrigeration Cycle
- The Jet Engine
- Hohmann Transfer Orbit
- Heavy Load at Midspan
- Load Near a Support
- Gear Train for a Clock
- One-to-One Gears
- Slow Sampling Aliasing
- Adequate Sampling
- Euler Buckling Load
- Pressure Vessel Wall Thickness
- Heat Sink Fin Efficiency
- Pump Power
- Orifice Flow Rate
- Quantisation Noise vs Bits
- Duty Cycle and Average Power
- Solar Panel Output vs Angle
🔧 Intermediate
- Stress–Strain Curve
- Heat Exchangers
- Rocket Equation
- Aerodynamic Lift
- Drag Force
- Wind Turbine Power
- Proportional Control Only
- Tuning for Overshoot
- Fourier Series: Triangle Wave
- Amplitude Modulation
- RC Filter Frequency Response
- The Diode I–V Curve
- Solar Cell I–V Curve
- PID: Integral Windup
- PID: Derivative Damping
- Fourier Series with One Harmonic
- Fourier Series with Many Harmonics
- Hooke’s Law for Materials: Strain Energy
- Fatigue: S–N Curve
- Strain Gauge Bridge Output
- Thermocouple Voltage
- Antenna Gain and Beamwidth
- Friis Free-Space Path Loss
- Efficiency of Power Transmission
- Battery Capacity vs Discharge Rate
- Lever Mechanical Advantage
- Pulley System Advantage
- Screw Thread Mechanical Advantage
- Brake Stopping Distance
- How a Dam Generates Electricity
- How a Solar Cell Works
🚀 Advanced
- Proportional–Integral–Derivative Control
- Feedback Control Loops
- Fourier Series: Square Wave
- Fourier Series: Sawtooth Wave
- Sampling and the Nyquist Limit
- Low-Pass Filters
- Pulse-Width Modulation
- Shannon Channel Capacity
- Op-Amp Amplifier Gain
- The Transistor as a Switch
- Battery Discharge Curve
- Reliability and Failure Rate
- Queueing and Utilisation
- Additive Manufacturing (3D Printing)
- The Engineering Design Process
- Error-Detecting Codes
- Data Compression
- Signal-to-Noise Ratio in Decibels
- Nyquist Rate for Audio
- Betz Limit for Wind Turbines
- How an Elevator Works
- How a Wind Turbine Works
- The Power Grid
- Smart Thermostat Control
- How Radar Works
- How Touchscreens Work
- How Robots Navigate (SLAM)
- Systems Engineering V-Model
- Specific Strength of Materials
- Energy Densities of Storage
Frequently asked questions
What will I learn in Engineering?
Structures, machines, control and signals. Each topic has a live animation, a lesson and a quick quiz.
Where should I start?
Try “Stress–Strain Curve” from the Popular list, or any beginner topic in Browse.
Are the topics in a set order?
Browse groups topics by level, with beginner topics first. Each topic’s FAQ names the topic to read before it.
Other subjects
Mathematics
Functions, calculus, geometry, probability
Physics
Motion, waves, fields and the quantum world
Chemistry
Atoms, bonds, reactions and solutions
Biology
Genes, cells, bodies and ecosystems
Computer Science
Algorithms, data, logic and machine learning
Earth & Space
Planet, climate, stars and the cosmos