Who co-created the UNIX operating system in 1969 with Dennis Ritchie?
Answer: C
Ken Thompson created UNIX with Dennis Ritchie at Bell Labs in 1969.
Thompson wrote the first version in assembly on a PDP-7; Ritchie then created the C language and the system was rewritten in it, which made it portable to other machines - the decisive step.
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The input used by an antenna or cable to a TV set uses frequencies called:
Answer: B
The signal an antenna or cable feeds to a television is RF - radio frequency.
The tuner converts it to a lower intermediate frequency (IF) for amplification, and the picture and sound are then recovered as video and audio frequency signals.
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What does AC and DC stand for in the electrical field?
Answer: A
AC is alternating current and DC is direct current.
In alternating current the direction reverses periodically - 50 times a second in India - which is what allows transformers to change the voltage for transmission. Direct current flows one way only, as from a battery.
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The NTSC (National Television Standards Committee) is also used in the country of...?
Answer: A
Japan also used the NTSC television standard.
NTSC was used in North America, Japan, South Korea and parts of South America. France used SECAM, and Germany and England used PAL.
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Which is NOT an acceptable method of distributing small power outlets throughout an open plan office area?
Answer: D
Extension cords are not an acceptable way of distributing power in an open-plan office.
They are a trip hazard, are easily damaged and overloaded, and are meant for temporary use only. Power poles, skirting trunking and flush floor ducts are the proper permanent methods.
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Sometimes computers and cache registers in a foodmart are connected to a UPS system. What does UPS mean?
Answer: D
UPS here means uninterruptible power supply.
It holds a battery and an inverter and switches over within milliseconds of a mains failure, so tills and computers do not lose the transaction in progress.
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What does VVVF stand for?
Answer: D
VVVF stands for variable voltage variable frequency.
An induction motor's speed is proportional to the supply frequency, so a VVVF drive varies the frequency to control speed, and varies the voltage with it to keep the magnetic flux constant. It is used in lifts, trains and industrial drives.
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Who is largely responsible for breaking the German Enigma codes, created a test that provided a foundation for artificial intelligence?
Answer: A
Alan Turing broke the German Enigma codes and devised the Turing test.
His work at Bletchley Park is credited with shortening the Second World War substantially. The test he proposed in 1950 - whether a machine's replies are indistinguishable from a person's - remains a founding idea of artificial intelligence.
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The transformer that develops the high voltage in a home television is commonly called as?
Answer: B
The transformer that generates the high voltage in a television is the flyback.
It works from the rapid collapse of current at the end of each horizontal scan line - the flyback - and steps that pulse up to about 25,000 volts for the picture tube.
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When measuring the characteristics of a small-signal amplifier, say for a radio receiver, one might be concerned with its "Noise..."?
Answer: D
The measure of interest is the amplifier's noise figure.
It states in decibels how much worse the signal-to-noise ratio is at the output than at the input. In a receiver the first stage's noise figure dominates, which is why the front-end amplifier is designed for low noise above all.
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