What does AC and DC stand for in the electrical field?

On December 12, 1901, a radio transmission received by Guglielmo Marconi resulted in the first transmission of a transatlantic wireless signal (Morse Code) from Poldhu, Cornwall, to St. John's, Newfoundland.

The terminals of FETs are called gate, drain and source. You might be more familiar with bipolar junction transistors (BJTs), which have terminals called base, collector and emitter. FETs were conceptualized first, but BJTs were easier to produce and so developed sooner.

Useful in tuning and filtering circuits, it blocks DC while passing AC. How much charge a capacitor can store is its capacitance, measured in farads.nn

Phil Zimmermann created the first version of PGP encryption in 1991. Pretty Good Privacy (PGP) is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting and decrypting texts, E-mails, files, directories and whole disk partitions to increase the security of e-mail communications.

According to many stories surrounding the origin of the compact disc, 74 minutes was settled on because it would comfortably contain all of Beethoven's 9th symphony on one disc. Although some stories reference a specific Sony higher-up who claimed this as his favorite piece of music, stories differ. All that's known for sure is that Sony insisted on this and won out over Phillips' original 60 minute proposal.

An uninterruptable power supply (UPS) is a backup power supply, such as a battery, that provides emergency power in the event that power is lost from the main supply.