Science and Technology Section 1
Practice and master this topic with our carefully crafted questions.
The IEEE (Institute of Electrical and Electronics Engineers) was formed in 1963 by the merger of the Institute of Radio Engineers (IRE, founded 1912) and the American Institute of Electrical Engineers (AIEE, founded 1884).
No answer description available for this question.
No answer description available for this question.
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.
No answer description available for this question.
The HF band is based on frequencies 3 to 30 Mhz. AM radio stations are in the HF band but normally are stated in kilohertz.
A collection of atoms or molecules that can be excited to a higher energy state is called an active medium. Before lasing can occur, the active media is "pumped". The process of raising the atoms in the active media from a lower energy state to a higher state is like pumping water up from a well.
No answer description available for this question.
The squirrel cage motor is the only one without any connection to the armature.
A given signal's second harmonic is twice the given signal's fundamental frequency. Harmonics are generated when there are non-linearities in an amplifier (there are always non-linearities). The worse the non-linearities, the more harmonics. A signal at 27.5 MHz (approximate frequency for US citizen's band) would have a second harmonic at 55.0 MHz (on US channel 2!). Can you see why there might be problems? A CB operator might do well to place a low-pass filter on his radio.