Computer Awareness GK Questions with Answers – Page 12

UPI was launched by NPCI in 2016 as a system that lets a user link several bank accounts to one mobile application and transfer money instantly using a virtual payment address or a QR code, without sharing account numbers.

NavIC is the operational name of the system formally called the Indian Regional Navigation Satellite System, built by ISRO so that the country would not depend on a foreign constellation for positioning in a crisis.

The 802.15 family covers wireless personal area networks, the very short-range links meant to join the devices a single person carries, and Bluetooth was standardised within it as IEEE 802.15.1.

An accelerometer measures acceleration along three axes, which includes the constant pull of gravity, so the phone can work out which way is down and therefore how it is being held.

NFC is deliberately designed for extremely short range, so the two devices must be touching or nearly touching before any data passes.

GSM is the European-born digital standard that replaced the analogue first generation networks; it introduced the removable SIM card, digital encryption of the radio link, international roaming and the short message service, on which a plain text message is limited to one hundred and sixty characters.

Android uses a modified Linux kernel at its lowest layer to manage memory, processes, power and device drivers, and builds its own runtime, libraries, application framework and user interface above it.

The International Mobile Equipment Identity is a fifteen-digit number assigned to every handset, made up of a code identifying the type approval of the model, a serial part and a final check digit.

The SIM is a small smart card issued by the operator that stores the subscriber identity, the authentication keys used to prove that identity to the network, and a limited amount of contact and message data.

A telephone conversation requires both parties to speak and listen at the same time, so a mobile link must carry traffic in both directions together.

LTE is the radio access technology of fourth generation mobile networks, standardised by the Third Generation Partnership Project.

A coaxial cable is built around a single solid or stranded copper wire at the axis, which carries the signal.

Infrared lies just below visible light in frequency, and like visible light it is stopped by an ordinary wall.

Transmission media fall into two families. A guided or bounded medium confines the signal to a solid conductor or light pipe, and the three guided media are twisted pair, coaxial cable and optical fibre.

A computer works with digital signals, a series of ones and zeros, while an ordinary telephone line was built to carry an analog voice signal.

The RJ-45 is the eight-position modular plug crimped on to the end of an unshielded twisted pair cable of category 5e or 6 and pushed into the network port of a computer, switch or router.

A walkie-talkie allows both parties to speak and both to listen, so communication is two-way, but the set has a single push-to-talk switch and one person must release it before the other can be heard.

Electromagnetic interference acts on moving charge, so any medium that carries a signal as an electric current can pick up noise from motors, fluorescent lamps, lightning and nearby cables.

The fibre has a core of higher refractive index surrounded by a cladding of lower refractive index. Light that enters the core and meets the boundary at an angle greater than the critical angle is reflected entirely back into the core, with none of it refracted away into the cladding.

In frequency division multiplexing each channel is given its own slice of the frequency band, and a small unused strip called a guard band is left between two neighbouring channels so that one does not spill into the next.