Hardware and Operating Systems Essentials (D386)

Correct Answer:

Power supply unit (PSU)

Explanation:

The power supply unit (PSU) is responsible for converting alternating current (AC) from a wall outlet into direct current (DC), which is used by the computer's internal components. It distributes the correct voltages to devices like the motherboard, CPU, hard drives, and graphics card. Without a functioning PSU, the computer cannot power on or operate properly. It is a foundational component in all desktop systems.

Why Other Options Are Wrong:

Motherboard

The motherboard distributes power received from the PSU to individual components, but it does not convert power from AC to DC. It depends on the PSU for its power input and serves mainly as a connection hub.

CPU fan

The CPU fan helps regulate temperature by dissipating heat from the processor. It is a cooling component and does not manage or convert electrical power.

Graphics processing unit (GPU)

The GPU processes graphical data and is one of the major power consumers in a system. However, it does not manage or convert electrical power. It relies on the PSU to receive the correct power levels.

Correct Answer

C. Smart phone

Explanation

A smartphone integrates multiple functionalities, combining features of PDAs, mobile phones, music players, video players, and gaming devices into one portable device. Smartphones have become popular because they offer convenience by merging various standalone gadgets into one compact unit. Users benefit from having diverse capabilities accessible in one handheld device.

Why Other Options Are Wrong

A. Handheld computer

A handheld computer, or PDA, focuses primarily on personal productivity, scheduling, and information management but typically lacks full cellular phone capabilities. These devices do not integrate all features, like digital music, video playback, or gaming, as effectively as smartphones do. Hence, handheld computers do not match the described multifunctional combination device.

B. Tablet PC

A tablet PC combines computing power with portability and touch-screen capabilities but usually lacks primary phone functionalities. Tablets often require separate apps or external methods for communication, and typically don't integrate cellular phone features as their primary function. Thus, tablet PCs don't fulfill the described integration as fully as smartphones.

D. Netbook

A netbook is essentially a small, lightweight laptop primarily focused on internet browsing and basic computing tasks. It does not typically include built-in cellular phone functionality or handheld portability required for gaming or direct calling. Hence, netbooks fail to meet the description of an all-in-one device like a smartphone.

Correct Answer

b. They are limited to the programs already installed during production.

Explanation

Smartphones are designed to allow users to download and install additional apps after production. This flexibility enables customization, upgrading, and extending the functionality of smartphones well beyond factory-installed software. Thus, stating smartphones are limited only to pre-installed applications is false.

Why other options are wrong

a. They combine phone, PDA, and MP3 player capabilities.

Smartphones indeed combine multiple functionalities including communication, personal digital assistant (PDA), and media playback such as MP3 capabilities. They integrate multiple devices into one convenient form. Hence, this statement correctly describes smartphones.

c. They run a mobile operating system.

Smartphones rely on specialized mobile operating systems (like Android or iOS) optimized for portable devices. These operating systems provide interfaces and capabilities specific to mobile usage. Therefore, this statement correctly represents smartphone functionality.

d. They are convergence devices.

Smartphones serve as convergence devices, combining various technology platforms like communication, entertainment, and personal productivity. This characteristic accurately describes their multifunctionality and integration of several devices. Thus, this statement is accurate.

Correct Answer

d. Selection

Explanation

The described programming logic utilizes a selection (or conditional) structure. Selection logic involves making decisions based on specific conditions—here, the condition is whether the user is logged in. Depending on that condition, the logic branches to continue checkout or prompt login, clearly indicating a selection structure.

Why other options are wrong

a. Encapsulation

Encapsulation is an object-oriented programming concept that bundles data with related methods, ensuring that internal details remain hidden. It does not describe conditional logic or decision-making based on login status. Therefore, encapsulation does not apply to this scenario.

b. Inheritance

Inheritance involves deriving a new class from an existing one, inheriting its properties and behaviors. It does not relate directly to conditional decision-making or checking user login states within procedural logic. Thus, inheritance doesn't fit the provided example.

c. Sequence

Sequence refers to executing programming statements or operations sequentially without conditional branching. Since this scenario explicitly involves checking conditions (if logged in), pure sequential logic isn't applicable. Thus, it doesn't fit the described process correctly.

Correct Answer

b. Asynchronous DRAM

Explanation

Asynchronous DRAM operates independently of the CPU’s external clock signal, meaning it doesn't synchronize data transfers with the system clock. This allows it to function without waiting for synchronization signals, but generally at lower efficiency and speed compared to synchronous memory types. Thus, the asynchronous nature differentiates it from synchronous alternatives.

Why other options are wrong

a. Synchronous DRAM

Synchronous DRAM (SDRAM) requires synchronization with the CPU’s external clock, providing faster, more predictable performance. Because it depends on the CPU clock for data transfers, it is not asynchronous. Thus, it's incorrect for this question.

c. DDR SDRAM

DDR SDRAM (Double Data Rate Synchronous DRAM) also relies on synchronization with the CPU’s clock signal, transferring data twice per clock cycle. This clearly makes it synchronous, not asynchronous. Hence, it's incorrect.

d. Static RAM

Static RAM (SRAM) is extremely fast and is often synchronized with the CPU’s external clock, especially when used in cache memory. Although faster than DRAM, SRAM typically still aligns with the CPU clock for data access, making it synchronous, not asynchronous.

Correct Answer

D. One user, too large to carry around, several components

Explanation

A desktop computer is designed for use by a single person at a fixed location and consists of separate components, including a monitor, keyboard, mouse, and a computer tower. Its size and multiple components mean it isn't easily portable or convenient to carry from place to place. These characteristics clearly distinguish desktop computers from portable or handheld devices.

Why Other Options Are Wrong

A. Fits in a pocket, has a touch screen

Devices fitting in a pocket with touchscreens are typically smartphones or similar handheld devices. Desktops are significantly larger and lack portability. Thus, this description doesn't match desktops at all.

B. Portable, single user

Portable devices used by a single user describe laptops or tablets, not desktops. Desktops are stationary devices intended for use at a fixed location and typically lack portability features. Therefore, desktops don't align with this option.

C. Multiple users, special room

Computers designed for multiple users in special rooms describe mainframe or server systems. Desktops are intended for individual users and do not require special environmental conditions or separate rooms. Hence, this does not describe desktops accurately.

Correct Answer

a. Physical size

Explanation

The primary difference between a laptop and a notebook computer is physical size. Notebooks are generally smaller, thinner, lighter, and more portable than traditional laptops. Both offer similar functionality, but notebooks emphasize compactness and portability.

Why other options are wrong

b. Battery life

Battery life varies widely across both laptops and notebooks, making it not a definitive distinguishing factor. Both can offer either short or extended battery life depending on design and specifications. Thus, battery life isn't the primary difference.

c. Storage capacity

Both laptops and notebooks can have similar storage capacities depending on the configuration or specific model. Storage capacity alone doesn't distinguish the two device types significantly. Thus, it's not the primary differentiating factor.

d. Ease of use

Ease of use for both laptops and notebooks is similar due to their comparable interfaces, operating systems, and general design. Both are user-friendly and designed for ease of interaction. Thus, ease of use doesn't differentiate laptops from notebooks significantly.

Correct Answer

c. It's always free

Explanation

While Linux itself is open source, meaning its source code is freely available, not all Linux distributions are always free. Some specialized Linux distributions include commercial licenses, proprietary software components, or paid support services. Therefore, stating Linux is "always free" is incorrect.

Why other options are wrong

a. It's open source

Linux is well-known for its open-source nature, allowing users to access and modify its source code freely. This open-source status is one of Linux's defining characteristics. Hence, stating that Linux is open source is correct.

b. It's based on UNIX

Linux was initially developed as a Unix-like system, adopting many design principles and system structures from UNIX. Although Linux isn't directly derived from UNIX code, its architecture is explicitly UNIX-inspired, making this statement accurate.

d. It's an operating system

Linux indeed serves as an operating system, managing hardware and providing a platform for software applications. It provides core system functionalities such as memory management, file handling, and process control. Thus, it correctly identifies Linux as an operating system.

Correct Answer

D. The operating system allows the user to control the actions of software.

Explanation

The operating system's primary task is providing a user interface and enabling users to manage, control, and execute software applications. It acts as an intermediary between the user and software, allowing users to start, interact with, or terminate applications. Thus, the operating system empowers users to control software actions effectively.

Why Other Options Are Wrong

A. The operating system works with hardware to provide a network service.

While an OS can support networking, providing network services is typically a specialized function handled by separate software or services. Network management is not the primary purpose of an OS, but rather an additional capability. Thus, this option is incorrect.

B. The operating system is responsible for managing and updating all of a computer's programs.

Managing and updating programs are often tasks of specialized software or individual applications themselves, rather than primary OS functions. Operating systems provide environments for program execution but aren't primarily responsible for managing software updates across all applications. Hence, this option is incorrect.

C. The operating system works with software to provide a data processing service.

Data processing tasks, such as computations or information management, are usually performed by specific application software, not the operating system itself. The OS provides resources, but actual data processing is typically the responsibility of applications running on the OS. Therefore, this is incorrect as the primary function of an OS.