Optical fibre transmits light using the principle of ________.
Answer: A
Correct answer: total internal reflection
The core has a higher refractive index than the cladding, so light striking the boundary beyond the critical angle is reflected entirely back into the core. Repeating this along the length carries the signal with very little loss.
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Which technology is used in a compact disc to read the stored data ?
Answer: A
Correct answer: A laser beam
A CD drive shines a laser at the disc and detects the change in reflection at the edges of microscopic pits. Because nothing touches the surface, the disc does not wear with repeated reading, unlike magnetic tape.
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What will a UPS be used for in a building?
Answer: A
A UPS provides power to essential equipment when the mains fails.
An uninterruptible power supply holds a battery and an inverter, and switches over within milliseconds, so servers and medical equipment keep running long enough to be shut down safely or for a generator to start.
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'.BAK' extension refers usually to what kind of file?
Answer: A
A .BAK file is a backup file.
Many programs rename the previous version of a document to .BAK before saving the new one, so that the last good copy survives a crash or a mistaken edit.
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One million bytes-
Answer: D
One million bytes is about 1 MB.
Strictly a megabyte is \( 2^{20} = 1{,}048{,}576 \) bytes, since memory is addressed in powers of two. Disk manufacturers use the decimal million, which is why capacities appear smaller once formatted.
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What can be considered as basic building blocks of a digital circuit ?
Answer: C
The logic gate is the basic building block of a digital circuit.
AND, OR and NOT gates, built from transistors, can be combined to make any logical function, and from them come adders, multiplexers, flip-flops and eventually the whole processor.
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In a color television set using a picture tube a high voltage is used to accelerate electron beams to light the screen. That voltage is about?
Answer: C
A colour picture tube uses about 25,000 volts to accelerate the electron beams.
The flyback transformer generates it. At that energy the electrons excite the phosphors brightly enough to be seen in daylight, and the tube also emits some X-rays, which the leaded glass absorbs.
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Word "INTERPRETER" is related to -
Answer: C
Interpreter is a term from programming languages.
It executes source code directly, statement by statement, without producing a separate executable. That makes development quicker but execution slower. Python, Ruby and JavaScript are usually interpreted.
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Who invented keyboard ?
Answer: B
Christopher Latham Sholes invented the typewriter keyboard.
He patented the first practical typewriter in 1868 and devised the QWERTY layout, arranging common letter pairs apart so the typebars would not jam. The layout outlived the mechanism entirely.
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Which is not application software?
Answer: B
Windows NT is not application software - it is an operating system.
Photoshop, Word and PageMaker are applications: programs that do a job for the user. The operating system manages the hardware and provides the services the applications run on.
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