Fundamentals Questions and Answers

Answer: D

Correct answer: mechanical calculator

The abacus, some 5,000 years old, is a mechanical calculating aid: beads moved on rods represent the digits, and the operator performs the arithmetic. It stores no program and does nothing by itself, so it is a calculator rather than a computer - and certainly not electronic.

Answer: B

Correct answer: 6 digits

Two 16-bit words give 32 bits, of which the standard single-precision format uses 24 for the significand (23 stored plus one implied). Since

that is worth about 7 decimal digits, of which 6 can be relied on. Doubling the storage to 64 bits raises it to roughly 15.

Answer: A

Correct answer: Sorting

Sorting is arranging records into a defined order - alphabetical, numerical, by date. Classifying is grouping them by category, summarising is condensing them, and reproducing is copying.

Answer: C

Correct answer: 11

A set of Napier’s bones comprised eleven rods - one index rod plus one for each digit, with the multiples of that digit engraved down its length. Laying the rods for the digits of a number side by side reduced multiplication to reading off partial products and adding them - and division to the same process in reverse. Napier described them in 1617.

Answer: A

Correct answer: Pulse code modulation

PCM converts an analogue signal to digital in three steps: sampling it at regular intervals, quantising each sample to the nearest of a set of levels, and encoding that level as a binary number. It is how speech becomes bits in digital telephony, and how sound is stored on a CD - 44,100 samples a second at 16 bits.

Answer: C

Correct answer: Resembles both a digital and analogue computer

A hybrid computer combines the two: an analogue section measures continuously varying physical quantities, and a digital section computes and controls. Hospital intensive-care monitors are the standard example - analogue measurement of pulse and blood pressure, digital processing and display.

Answer: A

Correct answer: Binary Coded Decimal

BCD encodes each decimal digit separately in four bits, so 59 is stored as 0101 1001 rather than as the binary 111011. It wastes space, since six of the sixteen combinations are unused, but it converts to and from decimal without rounding - which is why it survives in financial and display applications.

Answer: C

Correct answer: Plotter

A plotter draws continuous lines rather than approximating them from dots, so curves and diagonals come out smooth at any size. For large technical drawings that is a quality no raster printer of the period could match.

Answer: B

Correct answer: Vacuum Tubes and Valves

First-generation computers (about 1940-56) - ENIAC, UNIVAC - switched with vacuum tubes. They were enormous, consumed great quantities of power, generated much heat, and failed often, since a machine with 18,000 tubes will always have one about to burn out. The transistor, in the second generation, cured all four problems at once.

Answer: B

Correct answer: Plotter

A plotter draws with pens or heads that move continuously over the paper, so it produces smooth, precise lines at large size - which is what engineering and architectural drawings need. A monitor gives no hard copy at all; the printers give raster output, which is fine for text but coarser for large line drawings.