Engineering Glossary: N
29 definitions in plain language.
29 terms beginning with N. Use the filter to narrow the list, or the letters to jump to another part of the glossary.
29 terms
- Natural frequency #
- The frequency at which a system vibrates freely after a disturbance. Mechanical design and mechanics Read more: Vibration, Isolation and Noise
- Natural logarithm #
- The logarithm to the base e (about 2.718), written ln. Math, units, quality and workshop
- NEC #
- National Electrical Code (NFPA 70): the US standard for safe electrical installation. Math, units, quality and workshop
- Negative feedback #
- Returning part of the output to the input to reduce gain and improve stability and accuracy. Electronics
- NEMA enclosure #
- A North American standard type for electrical enclosures, stating protection against dust, water and corrosion. Electrical power and machines
- NEMA frame #
- A standard motor frame size that fixes mounting dimensions and shaft height. Electrical power and machines
- Net present value #
- The value today of a stream of future cash flows, discounted at a chosen rate. Math, units, quality and workshop
- Neural network #
- A model made of layers of simple connected units whose weights are learned from data. Programming, data and computing
- Neutral #
- The conductor in an AC system that completes the circuit and is held near earth potential. Electrical power and machines
- Neutral axis #
- The line in a bent beam's cross-section where the bending stress is zero. Mechanical design and mechanics
- Newton #
- The SI unit of force: the force that gives a mass of one kilogram an acceleration of one meter per second squared. Math, units, quality and workshop Read more: Force Converter
- Newton's laws #
- Three laws of motion: a body keeps its motion unless a force acts; force equals mass times acceleration; every action has an equal and opposite reaction. Math, units, quality and workshop
- Newton's method #
- A numerical method for finding roots of an equation by repeatedly improving a guess using the slope. Math, units, quality and workshop
- Nitriding #
- Hardening the surface of steel by diffusing nitrogen into it at a relatively low temperature. Materials, manufacturing and measurement
- Noise #
- Unwanted random variation in a signal. Electronics
- Noise (acoustic) #
- Unwanted sound. Math, units, quality and workshop
- Nominal #
- The named or intended value of a dimension or rating, before tolerances. Math, units, quality and workshop
- Nominal pipe size #
- The standard size name of a pipe, which is not the exact diameter. Fluids, heat and thermodynamics Read more: Steel Pipe Sizes (NPS and DN, Schedule 40 and 80)
- Non-ferrous metal #
- A metal that does not contain iron as its main element, such as aluminum, copper and titanium. Materials, manufacturing and measurement
- Normal distribution #
- The bell-shaped distribution that describes many random variations, set by its mean and standard deviation. Also called the Gaussian distribution. Math, units, quality and workshop
- Normalizing #
- Heating steel above its critical temperature and cooling it in air to refine the grain and make the structure uniform. Materials, manufacturing and measurement
- NPSH #
- Net positive suction head: the pressure head at the pump inlet above the vapor pressure; needed to avoid cavitation. Fluids, heat and thermodynamics Read more: Pump Power and Sizing Calculator
- NTU method #
- A way of rating heat exchangers from the number of transfer units and the effectiveness. Fluids, heat and thermodynamics
- Numerical integration #
- Finding the area under a curve by adding up small pieces, as in the trapezoid rule. Math, units, quality and workshop
- Numerical method #
- An algorithm that finds an approximate answer by calculation instead of by an exact formula. Math, units, quality and workshop Read more: Numerical Methods
- NumPy #
- A Python library for fast arrays and numerical calculation. Programming, data and computing
- Nusselt number #
- A dimensionless number that compares convection with conduction in a fluid layer. Fluids, heat and thermodynamics
- Nut #
- A threaded part that screws onto a bolt or stud. Mechanical design and mechanics
- Nyquist theorem #
- A signal must be sampled at more than twice its highest frequency to be reconstructed without aliasing. Electronics