- Jubilee Clip
- A worm-gear hose clip
- Julia Set
- The set of all the points for a function of the form Z^2+C.
- Julian Calendar
- Introduced in 46 BC by the Roman ruler Julius Ceasar, this calendar assumes
a year of 365.25 days, and uses a cycle in which 3 "ordinary" years of 365 days
are followed by a "leap year" with 366 days.
- Julian Day
- Instituted by J. Julius Scaliger in 1582. The Julian date is independent of various calendars and chronological events.
- Jump Discontinuity
- A discontinuity in a function where the left and right-hand limits exist but are not equal to each other.
- A connection between two or more parts.
- Junction Box
- A box with a cover that serves the purpose of joining different runs of wire or cable
and provides space for the connection and branching of the enclosed conductors.
- Junction Diode
- A two-terminal device containing a single crystal of semiconducting material that
ranges from P-type at one terminal to N-type at the other.
- Junction Transistor
- A bipolar transistor constructed from interacting PN junctions.
- Junior Hacksaw
- A metal blade of hardened steel having small, close teeth on one edge, held under tension in a sprung U-shaped frame.
- The largest planet in our solar system.
- The geological period from 208 million to 146 million years ago.
- Jury Evaluation
- A name given to a field where the customer is given the opportunity to compare products and rank one versus the other.