Computer Awareness Mixed Quiz: Set 31

The correct answer is C, 15. 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. It can usually be displayed by dialling a short code and is printed under the battery or on the box. Because it identifies the device rather than the subscriber, it is the number quoted when a lost phone is reported so that the network can bar the handset. Option A, ten digits, is the length of an Indian mobile telephone number, which is why it is the commonest wrong answer. Option B, twelve digits, is the length of the Aadhaar number. Option D, twenty digits, matches the longer identifier printed on some SIM cards, not the IMEI.

The correct answer is A, Long Term Evolution. LTE is the radio access technology of fourth generation mobile networks, standardised by the Third Generation Partnership Project. The name records the intention of the standard bodies to let the existing GSM and UMTS networks evolve over the long term towards an all-IP system rather than be replaced overnight, and voice over LTE later brought ordinary calls on to the same data network. Option B, Last Time Evolution, is not a term used anywhere in telecommunications. Option C, Least Time Evolution, is likewise invented and has no technical meaning. Option D, Long Time Evolution, is the commonest wrong choice because it differs from the right answer by a single word, but the standard uses the word term, not time. Candidates should remember LTE with 4G and New Radio with 5G.

The correct answer is B, PSD. PSD, the Photoshop Document, keeps every layer, mask, channel and adjustment separately so that the artist can go back and change any of them, which an exported JPEG or PNG cannot do because those flatten the picture into one grid of pixels. Option A, CDR, is the native format of CorelDRAW, a vector drawing package. Option C, AI, is the native format of Adobe Illustrator, which is also a vector program and a common distractor because it too comes from Adobe. Option D, SVG, is the open Scalable Vector Graphics format of the World Wide Web Consortium, written in XML. The simple rule to carry into the hall is that Photoshop is raster and saves PSD, while Illustrator and CorelDRAW are vector and save AI and CDR.

The correct answer is D, Vijay Bhatkar. Vijay Bhatkar led the team at C-DAC that built PARAM 8000 in 1991 and is therefore described as the architect of India's PARAM series of supercomputers. Option A is wrong because Homi Jehangir Bhabha was the founder of the Indian atomic energy programme and of the Tata Institute of Fundamental Research, where TIFRAC was built, but he died in 1966, long before the PARAM project. Option B is wrong because Satish Dhawan was a leader of the Indian space programme and chairman of ISRO, remembered in the name of the launch centre at Sriharikota. Option C is wrong because Raj Reddy is an Indian-born computer scientist who worked on artificial intelligence and speech recognition in the United States and was not part of the PARAM project.

The correct answer is D. SAGA-220 was built by the Indian Space Research Organisation in 2011 using graphics processing units, so that pair is correct. Option A is wrong because Flosolver was built at the National Aerospace Laboratories in Bengaluru in 1986 and is counted as India's first parallel computer. Option B is wrong because the ANUPAM series of parallel computers was developed by the Bhabha Atomic Research Centre, so options A and B simply have their organisations exchanged. Option C is wrong because PACE, the Processor for Aerodynamic Computation and Evaluation, was built by ANURAG, a laboratory of the Defence Research and Development Organisation at Hyderabad, not by ISRO. The fourth line of this work is C-DAC's PARAM series, which began with PARAM 8000 in 1991. Param Padma of 2002 was the system that first took an Indian machine into the world list of fastest computers.

The correct answer is C, the XOR gate. Adding two single bits gives a sum that is 1 when exactly one of the bits is 1 and 0 when both are 0 or both are 1, which is precisely the XOR rule; so in a half adder the sum line comes from an XOR gate. A is wrong because the AND gate in a half adder produces the carry, which is 1 only when both bits are 1, and swapping sum with carry is the usual mistake here. B is wrong because an OR gate would wrongly give a sum of 1 when both bits are 1, and in any case the OR gate appears only in the full adder, where it combines the two carry signals. D is wrong because a NOR gate plays no part in the standard half adder at all. Remember the full sentence: half adder equals XOR for sum plus AND for carry, two inputs, no carry in.

The correct answer is B, Linux. 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 project began at a company called Android Inc., which Google acquired in 2005, and the first Android handset reached buyers in 2008. Option A is wrong because the Windows NT kernel underlies desktop Windows and the discontinued Windows Mobile line, not Android. Option C is wrong because kernels derived from Unix and BSD underlie Apple macOS and iOS, which are Android competitors rather than its base. Option D is wrong because Symbian was a complete mobile operating system of the era before Android, used mainly by Nokia, and it was never a kernel for Android.

The correct answer is B, John Napier. The Scottish mathematician John Napier published his work on logarithms in 1614, which turned multiplication into addition, and he then devised a set of numbered rods, Napier’s bones, with which products could be read off mechanically. Option A is wrong because William Oughtred used logarithms to make the slide rule in 1622, a development of Napier’s idea rather than its origin. Option C is wrong because George Boole gave the algebra of logic in 1854, the basis of digital circuit design, not a calculating aid. Option D is wrong because Herman Hollerith built the punched card tabulating machine used in the United States census of 1890 and founded the company that became IBM. Logarithms turned long multiplication into simple addition and ruled scientific calculation until the pocket calculator arrived.

The correct answer is B, SVG. Scalable Vector Graphics stores a picture as mathematical descriptions of lines, curves and shapes written in XML, so the browser redraws it at whatever size is asked for and the edges stay perfectly sharp. That is why logos, maps and icons are kept as SVG. Option A, PNG, is a raster format: it is a grid of pixels, excellent for lossless images with transparency, but it blurs when enlarged. Option C, TIFF, is also raster and is favoured in scanning and printing because it can hold very high bit depths. Option D, BMP, is the plainest raster format of all, storing pixels with little or no compression. The examinable distinction is that raster images are made of pixels and pixelate, while vector images are made of paths and scale freely.

The correct answer is C, Extended Binary Coded Decimal Interchange Code. EBCDIC is an 8-bit character encoding scheme developed by IBM in 1963 for its mainframe and midrange computers. Because it uses 8 bits for each character it can represent 256 different characters, twice as many as the 7-bit ASCII code, which handles 128. EBCDIC grew out of the older Binary Coded Decimal system and is still found on IBM mainframes, while ASCII became the standard for personal computers and Unicode now covers the scripts of the world, including Devanagari. A is wrong because the third word is Coded, not Control. B is wrong on two counts: the first word is Extended and the third is Coded. D is wrong because the expansion ends with Decimal Interchange Code, not Data Integration Code. Exam tip: EBCDIC is 8-bit and 256 characters, ASCII is 7-bit and 128 characters, Unicode is 16-bit and covers all scripts.

The correct answer is B, Global System for Mobile Communications. 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. Option A, General Switching Mode, is not a telecommunications standard and simply borrows two technical-sounding words. Option C, Generic Signal Modulation, is invented, although modulation is indeed part of how GSM encodes a signal. Option D, Global Satellite Messaging, is wrong because GSM is a terrestrial cellular standard that works through ground base stations, not through satellites. Keep GSM with 2G, UMTS with 3G and LTE with 4G, and remember that CDMA, or Code Division Multiple Access, was the rival second generation family in which every call was spread across the band under its own code rather than given a separate time slot.

The correct answer is A, REL. An external stylesheet is attached to a page with a link tag written inside the head section, and the tag needs two things: href, which gives the address of the CSS file, and rel, which tells the browser what the linked file is for. Writing rel equals stylesheet is what marks the file as a set of style rules; leave rel out and the browser has no reason to treat the file as CSS, so the page appears unstyled. B is wrong because style is a separate way of writing CSS, either as a style block in the head or as an attribute on one element, and it has no part in linking an external file. C is wrong because body holds the visible content of the page while the link tag belongs in the head. D is wrong because html is the root element that wraps the whole document and has nothing to do with loading a stylesheet. Exam tip: link rel equals stylesheet with href, placed in the head.

The correct answer is A, size of an object. In computer graphics the three basic two-dimensional transformations are translation, rotation and scaling. Scaling multiplies the coordinates of every point of an object by a scale factor, so the object grows when the factor is greater than one and shrinks when it lies between zero and one; uniform scaling uses the same factor along both axes and so changes the size without changing the proportions. Option B describes translation, which adds a fixed displacement to each coordinate and moves the object without resizing it. Option C is wrong for uniform scaling, since a square scaled equally in both directions is still a square; distortion of shape belongs to shearing or to unequal scaling. Option D is wrong because a single scaling matrix does not move an object's reference point in the way translation does.

The correct answer is C, B2C. Flipkart, Alibaba and Amazon run online marketplaces whose storefronts sell goods to individual shoppers, and a business selling to a consumer is business-to-consumer, or B2C. In this model a firm lists its products on a website or an app, the customer orders and pays online, and the goods reach the home, so the shop, the salesman and the cash counter are all replaced by software. B2C is the commonest face of e-commerce and the one ordinary buyers meet every day. A is wrong because consumer-to-business, C2B, is the reverse case, where an individual offers a service or product to a firm, as a freelance designer or a blogger selling advertising space does. B is wrong because consumer-to-consumer, C2C, means one individual selling to another through a platform such as OLX. D is wrong because business-to-business, B2B, covers a firm selling to another firm, as IndiaMART does. Exam tip: Amazon and Flipkart are B2C, OLX is C2C and IndiaMART is B2B.

The correct answer is A, a few centimetres. NFC is deliberately designed for extremely short range, so the two devices must be touching or nearly touching before any data passes. This limitation is itself the security feature that makes the technology suitable for contactless card payments, tap-to-pay on phones, transit tickets and identity tags, since an attacker cannot read the exchange from across a room. Option B, about ten metres, is the usual working range of Bluetooth, which is the commonest confusion in this question. Option C, about one hundred metres, is closer to the range of a Wi-Fi access point in open conditions. Option D, several kilometres, describes a cellular link to a base station or a long-range radio system, far beyond anything NFC attempts.

The correct answer is C, RAM. Random access memory holds the programs and data the processor is working on at that moment, and it is volatile: the instant the power supply is cut, everything stored in it disappears. That is why unsaved work is lost in a power failure.

Option A, ROM, is read-only memory, written normally at manufacture and non-volatile, so it keeps the start-up instructions safely when the machine is switched off. Option B, the hard disk, is secondary storage and is non-volatile by design, since its whole purpose is to hold data permanently. Option D, EPROM, is erasable programmable read-only memory, a ROM variant whose contents can be wiped with ultraviolet light and rewritten, but it too retains data without power. The single word to test in such a question is volatile, and only RAM carries it.

The correct answer is C, CMYK. CMYK stands for cyan, magenta, yellow and key or black, and it is a subtractive model: the inks sit on white paper and subtract wavelengths from the light falling on it, so adding all of them together moves the result towards black. Option A, RGB, is the additive model of red, green and blue light used by monitors, projectors, cameras and scanners, where all three at full strength give white. Option B, HSB, is a way of describing a colour by hue, saturation and brightness that artists find convenient, but it is not a printing model. Option D, YUV, separates brightness from colour information and is used in video transmission to save bandwidth. The examiner's favourite one line is that screens are additive RGB and print is subtractive CMYK.

The correct answer is C, the accelerometer. 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. The system uses that reading to rotate the screen, to count steps and to detect shaking. Option A is wrong because the proximity sensor detects an object close to the top of the screen and blanks the display when the phone is lifted to the ear during a call. Option B is wrong because the ambient light sensor measures the brightness of the surroundings and adjusts screen brightness automatically. Option D is wrong because the magnetometer senses the earth magnetic field and serves as the compass for map applications. A gyroscope refines rotation sensing but the basic orientation switch belongs to the accelerometer.

The correct answer is B, instructions telling an instrument what to play. MIDI stands for Musical Instrument Digital Interface, a standard of the early nineteen eighties by which synthesisers, keyboards and computers exchange messages about which note begins, how hard it is struck, how long it lasts and which instrument voice should sound. Because only these instructions are stored, a MIDI file is tiny compared with recorded audio, and the same file can sound quite different on two synthesisers. Option A describes a waveform format such as WAV, which samples the actual air pressure of a performance. Option C belongs to formats such as MP4 or AVI. Option D is wrong because MIDI carries no picture at all, and printed scores come from notation software. Remember the contrast: WAV records sound, MIDI records the performance's instructions.

The correct answer is C, IEEE 802.15. 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. Its working range is about ten metres in the common low-power class, which suits earphones, speakers, keyboards and file transfer. Option A is wrong because IEEE 802.3 is the Ethernet standard for wired local area networks. Option B is wrong because IEEE 802.11 is the Wi-Fi family for wireless local area networks, which is the usual distractor since both are wireless. Option D is wrong because IEEE 802.16 is WiMAX, a broadband wireless access standard designed for metropolitan area coverage. Learning the four together, 802.3, 802.11, 802.15 and 802.16, settles a whole family of questions.