IB Computer Science HL

A closed-loop system uses feedback from sensors to adjust its output, making the statement true.

Digital sensors convert physical quantities into discrete signals, specifically a stream of binary data (1s and 0s) that a computer can process.

Computer control systems rely entirely on sensors to gather data about the environment in order to make decisions; therefore, not requiring sensors is incorrect.

An actuator is a component that performs an action (like moving or heating). A thermostat is a sensor that measures temperature, not an actuator.

Paging is a memory management scheme that allows a computer to store and access more memory than is physically available in RAM by swapping data between RAM and the disk.

A system interrupt is a signal sent to the processor by hardware or software indicating that an event needs immediate attention. This causes the CPU to temporarily pause its current task to handle the request.

Smartphones contain a CPU, memory, storage, and input/output capabilities, which are the fundamental components of a computer. They perform calculations and execute software instructions just like traditional computers.

An analogue radio processes continuous signals using electronic components like transistors and capacitors without converting them into digital binary data. It lacks the stored-program architecture required to be classified as a computer.

Digital cameras use microprocessors to process image data from sensors, manage storage, and run firmware. These components fulfill the definition of a computer.

The CPU performs arithmetic, logic, and control operations. Long-term data storage is handled by secondary storage devices like hard drives or SSDs, not the CPU itself.

A recursive function is defined by its ability to call itself during execution to solve smaller instances of the same problem. This process continues until a base case is reached.

In recursion, the base case is the condition that terminates the recursive calls. Without it, the function would call itself indefinitely, leading to a stack overflow error.

Arrays have a fixed size defined at creation, whereas linked lists can grow or shrink dynamically by allocating and deallocating memory for individual nodes as needed.

A queue follows the First-In-First-Out (FIFO) principle, where the first element added is the first one to be removed. This is analogous to a line of people waiting for service.

A stack follows the Last-In-First-Out (LIFO) principle, where the most recently added element is the first one to be removed. This is analogous to a stack of plates.

A mutator method, commonly known as a setter, is used to modify the state of an object by changing the value of its private fields.

Having multiple constructors is called constructor overloading. It is perfectly valid as long as the constructors have different parameter lists (different signatures).

Polymorphism allows objects to be treated as instances of their parent class, enabling different classes to provide their own specific implementation of a method defined in a common interface or superclass.

The 'private' access modifier restricts visibility so that the member can only be accessed within the class where it is declared.

Encapsulation is the bundling of data and methods that operate on that data into a single unit, and restricting direct access to some of the object's components to protect the internal state.

A dependency represents a temporary relationship where one class uses another class, often as a parameter in a method or a local variable.

Aggregation represents a 'has-a' relationship where one class contains another, but the contained object can exist independently of the container.

UML stands for Unified Modelling Language, which is a standardized general-purpose modelling language used in software engineering to visualize the design of a system.

Integer, Float, and Boolean are primitive data types, while an Array is a complex or composite data structure that can hold multiple values.

A compiler translates the entire source code into machine code (an executable file) before the program is run, unlike an interpreter which translates code line-by-line during execution.

Assembly is a low-level programming language that is very close to machine code, whereas C#, Java, and Ruby are high-level languages that provide more abstraction from hardware.

Bubble sort works by repeatedly stepping through the list, comparing adjacent elements, and swapping them if they are in the wrong order. This process 'bubbles' the largest unsorted element to the end of the array in each pass.

Binary search works by repeatedly dividing the search interval in half. This process requires the data to be sorted so that the algorithm can determine whether the target value is in the left or right half.

Concurrency refers to the ability of a system to handle multiple tasks or processes during overlapping time periods. It is distinct from parallelism, which involves executing tasks simultaneously.

Planning ahead in software engineering involves designing systems with scalability and future compatibility in mind. This helps ensure that the software can adapt to changing requirements or technological shifts.

Redundancy is the inclusion of extra components or resources that are not strictly necessary for functioning, but serve as backups to prevent system failure. It is a key strategy for reliability.

A Local Area Network (LAN) connects devices within a limited geographical area, such as a home, office, or building. WAN covers larger areas, while PAN is for personal devices.

Fibre optic cables transmit data using light pulses, which allows for significantly higher bandwidth and speed compared to electrical signals in copper or coaxial cables.

FLAC (Free Lossless Audio Codec) is a lossless format, meaning it compresses audio without losing any original data. JPG, MP4, and MP3 are all lossy formats that discard data to reduce file size.

A Denial of Service (DoS) attack aims to make a machine or network resource unavailable to its intended users by flooding it with excessive requests, overwhelming the server.

UDP stands for User Datagram Protocol. It is a connectionless communication protocol used across the internet for time-sensitive transmissions.

UDP is a connectionless protocol that does not perform error checking or packet verification. TCP is the protocol responsible for ensuring all packets arrive correctly.

TCP stands for Transmission Control Protocol, which is one of the main protocols of the Internet Protocol suite. It provides reliable, ordered, and error-checked delivery of a stream of octets between applications.

Two's complement is a mathematical operation on binary numbers that allows computers to represent both positive and negative integers using a standard binary format.

ASCII (American Standard Code for Information Interchange) is a character encoding standard that assigns numeric values to characters, allowing computers to store and process text.

To convert 00110010 to hex, split it into two 4-bit nibbles: 0011 (3) and 0010 (2). Combining them gives 32 in hexadecimal.

11001010 in decimal is (1128) + (164) + (032) + (016) + (18) + (04) + (12) + (01) = 128 + 64 + 8 + 2 = 202.

To convert 66 decimal to hex, divide 66 by 16: 66 / 16 = 4 with a remainder of 2. The result is 42 in hexadecimal.

To convert 25 decimal to binary: 25 / 2 = 12 (rem 1), 12 / 2 = 6 (rem 0), 6 / 2 = 3 (rem 0), 3 / 2 = 1 (rem 1), 1 / 2 = 0 (rem 1). Reading remainders upwards gives 11001, which is 00011001 in 8-bit.

In computing, a gigabyte (GB) is defined as 1 billion bytes (10^9 bytes) in the decimal system, though it is sometimes used to refer to 1024^3 bytes (gibibyte) in binary contexts.

A kilobit is 1000 bits. Since bits are the 1s and 0s, 1000 of them make a kilobit.

A bit (short for binary digit) is the smallest unit of data in a computer, representing a single 1 or 0.

Automatic updates are a feature, not a deployment issue. The other options describe challenges related to physical distribution, bandwidth usage, or slow manual processes.

Enterprise IT refers to software and systems managed and run entirely within an organization's own internal infrastructure, as opposed to cloud-based services.

Software as a Service (SaaS) is a software distribution model in which a third-party provider hosts applications and makes them available to customers over the internet.

A wireframe is a visual guide that represents the skeletal framework of a website or application, showing the layout and placement of elements before final design.

A flow chart is a visual representation of a process or program logic, showing the sequence of steps and how different functions interact. Gantt charts are for project scheduling, context diagrams show system boundaries, and prototypes are preliminary models.