A computer virus that actively attacks an anti-virus program or programs in an effort to prevent detection is...
Answer: B
A virus that attacks anti-virus software to avoid detection is a retrovirus.
It disables the scanner, corrupts its signature database or blocks its updates. The name is borrowed from biology, where a retrovirus subverts the host's own machinery.
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Which is a type of Electrically-Erasable Programmable Read-Only Memory?
Answer: A
Flash memory is a type of electrically erasable programmable read-only memory.
It is erased in blocks rather than byte by byte, which makes it much faster than earlier EEPROM. It holds its contents without power, and is what USB drives, SSDs and memory cards are made of.
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Which motor is NOT suitable for use as a DC machine?
Answer: C
The squirrel cage motor cannot be used as a DC machine.
It is an induction motor: it works only on alternating current, whose changing field induces current in the rotor bars. Permanent magnet, series and synchronous machines can all be built to run on direct current.
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AOL stands for:
Answer: D
AOL stands for America Online.
It was the dominant consumer internet service of the 1990s in the United States, its CDs mailed to millions of households. Its merger with Time Warner in 2000 is often cited as the worst in corporate history.
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Made from a variety of materials, such as carbon, which inhibits the flow of current...?
Answer: C
A component made of carbon or similar material to oppose the flow of current is a resistor.
Its value follows Ohm's law, \( V = IR \), and it dissipates the energy as heat. Chokes and inductors oppose changes in current rather than current itself, and capacitors block direct current entirely.
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ROM is -
Answer: B
ROM is non-volatile.
Its contents survive when power is removed, which is why the firmware that starts a computer is held in it. RAM is volatile and loses everything the moment power is cut.
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Once the active medium is excited, by which physical process is the first photons of light are produced ?
Answer: B
The first photons in a laser are produced by spontaneous emission.
An excited atom drops to a lower level of its own accord and emits a photon in a random direction. A few of those photons happen to travel along the axis, and they set off the stimulated emission that builds the beam.
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What program runs first after computer is booted and loading GUI?
Answer: D
Authentication runs first once the GUI has loaded.
The logon process presents the sign-in screen and verifies the credentials before the user's desktop, shell and startup programs are launched, so that everything afterwards runs in that user's security context.
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Main circuit board in a computer is...
Answer: D
The main circuit board in a computer is the motherboard.
It carries the processor socket, memory slots, chipset, expansion slots and connectors, and the buses that link them, so every other component plugs into or communicates through it.
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Which among following organization is concerned with databases ?
Answer: D
Oracle is the organisation concerned with databases.
Its relational database, released in 1979, was the first commercial implementation of Codd's model and remains dominant in large enterprises. Asus, Intel and Motorola are hardware makers.
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