Computer Hardware and Software Questions and Answers

Answer: B

Correct answer: Power on Self Test

The POST runs at power-up and inventories the machine: it counts memory, reads the date and time from CMOS, and detects the ports and display adapters present.

Answer: D

Correct answer: First 64k of extended

The High Memory Area is the first 64 KB above the first megabyte - that is, the first 64 KB of extended memory - and it is reachable in real mode through an artefact of address wrapping, which is why DOS could be loaded into it.

Answer: A

Correct answer: True

A SCSI host adapter carries its own BIOS in ROM, so that the machine can boot from a SCSI disk before any driver is loaded. That ROM occupies a range in the reserved memory area as well as the adapter's I/O ports.

Answer: B

Correct answer: It converts mains AC into the low-voltage DC the components need

The power supply unit converts the alternating current from the mains - 230 volts in India - into the low-voltage direct current the components require, chiefly +12 V, +5 V and +3.3 V, delivered through standard connectors. Its capacity is quoted in watts, and it must exceed the total draw of the components, with the graphics card and processor usually accounting for most of it. Efficiency is rated by the 80 Plus scheme, and a more efficient unit wastes less energy as heat. The second option describes an UPS, an uninterruptible power supply, which is a separate external device containing a battery. It provides enough time to save work and shut down cleanly, and also protects against surges and voltage fluctuation. The PSU is a common cause of intermittent faults that look like something else - random restarts and instability under load - because an inadequate or failing unit fails only when demand rises.

Answer: B

Correct answer: 25Mhz

The DX2 runs its core at twice the bus speed, so an internal 50 MHz means an external

\[ \frac{50}{2} = 25\ \text{MHz} \]

Clock doubling raised processor speed without requiring faster and more expensive motherboards.

Answer: C

Correct answer: To allow additional cards to be fitted, extending the computer’s capabilities

An expansion slot accepts a circuit card that adds capability the motherboard does not itself provide - a graphics card, sound card, network card, capture card or additional storage controller. The modern standard is PCI Express, which comes in sizes described by the number of lanes: x1, x4, x8 and x16. Each lane is a serial connection, so bandwidth scales with the count, and a graphics card takes an x16 slot. A shorter card fits a longer slot and simply uses fewer lanes. It replaced the older PCI and AGP standards, and the shift from parallel PCI to serial PCI Express follows the same reasoning as USB and SATA: at high speeds, timing skew between parallel wires becomes the limiting factor. The other options describe different parts: the processor sits in a socket, the power supply uses dedicated connectors, and BIOS settings live in CMOS memory kept alive by a battery.

Answer: C

Correct answer: Hard disk

The hard disk is a separate storage device connected to the motherboard, not a part of the processor. The CPU has three components. The arithmetic logic unit performs arithmetic and logical operations and sets the status flags - zero, carry, sign, overflow - that conditional branches test. The control unit fetches instructions, decodes them and directs the rest of the machine, generating the timing and control signals. The registers hold the operands and results being worked on, and are the fastest storage in the computer. Modern processors also carry cache on the same die, which blurs the boundary a little, and often an integrated graphics unit and memory controller as well. The processor operates in a repeating fetch–decode–execute cycle. The distinction the question tests is between what is inside the processor package and what is attached to it - and storage is always outside.

Answer: D

Correct answer: I/O controller

An I/O controller is a bare circuit board dense with semiconductors, and static discharge is exactly what damages those. A monitor, a power supply and floppy disks are all far more robust.

Answer: D

Correct answer: cold and dry

Charge cannot leak away through dry air, and cold air holds little moisture, so static builds and discharges most readily in cold, dry conditions.

Answer: B

Correct answer: Software stored permanently on a hardware device to control it

Firmware is software written into a hardware device to control it - permanent enough to be part of the device, but still code rather than circuitry. Hence the name, standing between hardware and software. The BIOS or UEFI on a motherboard is the familiar example, but firmware is present in almost everything: hard disks, SSDs, printers, routers, cameras, keyboards and washing machines all run their own. It was originally stored in ROM and unchangeable. Modern devices use flash memory instead, so firmware can be updated - which is what makes a router able to receive a security patch, and what makes a failed update capable of rendering a device useless, since the code that would let it recover is the code being replaced. The distinction from an operating system is one of level: firmware initialises and controls one device, while an operating system manages the whole machine and the software running on it.