IT &computer MCQ section 3 MCQ Questions & Answers Detailed Explanation

Answer: (d)

A computer virus is a computer programme that can replicate itself and spread from one computer to another. The term “virus” is also commonly, but erroneously, used to refer to other types of malware, including but not limited to adware and spyware programs that do not have a reproductive ability.

Malware includes computer viruses, computer worms, Trojan horses, most rootkits, spyware, dishonest adware and other malicious or unwanted software, including true viruses.

Answer: (a)

FORMAT is an MS-DOS external command.

Answer: (c)

As per the latest data of International Telecommunications Union, China had the largest number of internet users in the world (721,434,547) as of 30 June, 2016. India comes second with 462,124,989 internet users.

Answer: (a)

Ray Tomlinson is credited with developing the first viable e-mail program in 1971 for use on the ARPANET.

Although text messages were occasionally sent over the network, Tomlinson created the first program. it is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks.

Some early email systems required that the author and the recipient both be online at the same time, in common with instant messaging. Today’s email systems are based on a store-and-forward model.

Answer: (d)

Impact Printers refer to a class of printers that work by banging a head or needle against an ink ribbon to make a mark on the paper. This includes dot-matrix printers, daisy-wheel printers, and line printers. In contrast, laser and ink-jet printers are nonimpact printers.

Answer: (b)

Data is stored on the disc as a series of microscopic indentations. A laser is shone onto the reflective surface of the disc to read the pattern of pits and lands.

Because the depth of the pits is approximately one-quarter to one-sixth of the wavelength of the laser light used to read the disc, the reflected beam's phase is shifted in relation to the incoming beam, causing destructive interference and reducing the reflected beam's intensity. This pattern of changing the intensity of the reflected beam is converted into binary data.