j - A prefix used to indicate an imaginary number. (Operator j)
jack - Socket or connector into which a plug may be inserted.
JFET - Abbreviation for "Junction field effect transistor".
joule - The unit of work and energy.
junction - Contact or connection between two or more wires or cables. The area where the p-type material and n-type material meet in a semiconductor.
junction diode - diode. A semiconductor diode in which the rectifying characteristics occur at a junction between the n-type and p-type semiconductor materials.