Technology MCQs

✅ The correct answer is option C.
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.

✅ The correct answer is option D.
Extension cords can be a tripping hazard, and can be easily damaged, causing an unsafe situation. There are many ways of safely getting power to each work place, where wiring is protected and concealed.

✅ The correct answer is option C.
CDs reproduce 44,100 samples per second. Which has a maximum frequency reproduction of 22,050 Hz, or just a hair past the upper limit of human hearing. In this way CDs can theoretically reproduce any frequency in the human hearing range.

✅ The correct answer is option C.

✅ The correct answer is option A.

✅ The correct answer is option D.

✅ The correct answer is option A.

✅ The correct answer is option A.

✅ The correct answer is option B.
Spontaneous emission is what you see with most “glow in the dark” toys. You excite the toy by exposing it to bright light, then the toy glows in the dark by spontaneously emitting photons as the excited atoms relax back down to their normal state.

✅ The correct answer is option D.
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.