> For the complete documentation index, see [llms.txt](https://nec-license.gitbook.io/books/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nec-license.gitbook.io/books/2.-digital-logic-and-microprocessor/mcqs/mcqs-on-microprocessor/set-9.md).
# set-9
### 201. Which of the following controls the time slicing mechanism in a multitasking operating system?
1. Kernel
2. Single tasking kernel
3. Multitasking kernel
4. Application manager
Show me the answer
**Answer:** 3. Multitasking kernel
**Explanation:**
* The **multitasking kernel** controls the **time slicing mechanism** in a multitasking operating system. It allocates CPU time to different tasks, ensuring that each task gets a fair share of the processor's resources.
### 202. Which of the following provides time period for the context switch?
1. Timer
2. Counter
3. Time slice
4. Time machine
Show me the answer
**Answer:** 3. Time slice
**Explanation:**
* The **time slice** is the fixed amount of time allocated to each task in a multitasking system. When the time slice expires, a **context switch** occurs, and the CPU switches to the next task.
### 203. Which of the following can periodically trigger the context switch?
1. Software interrupt
2. Hardware interrupt
3. Peripheral
4. Memory
Show me the answer
**Answer:** 2. Hardware interrupt
**Explanation:**
* A **hardware interrupt** can periodically trigger a **context switch**. For example, a timer interrupt can signal the end of a time slice, causing the operating system to switch to another task.
### 204. Which interrupt provides system clock in the context switching?
1. Software interrupt
2. Hardware interrupt
3. Peripheral
4. Memory
Show me the answer
**Answer:** 2. Hardware interrupt
**Explanation:**
* The **hardware interrupt** from the system clock is used to trigger **context switching**. It ensures that tasks are given a fair share of CPU time by periodically interrupting the current task.
### 205. The special table in the multitasking operating system is also known as
1. Task control block
2. Task access block
3. Task address block
4. Task allocating block
Show me the answer
**Answer:** 1. Task control block
**Explanation:**
* The **Task Control Block (TCB)** is a data structure used by the operating system to store information about a task, such as its state, program counter, and register values. It is essential for context switching.
### 206. Which of the following stores all the task information that the system requires?
1. Task access block
2. Register
3. Accumulator
4. Task control block
Show me the answer
**Answer:** 4. Task control block
**Explanation:**
* The **Task Control Block (TCB)** stores all the information about a task, including its state, program counter, register values, and memory allocation. This information is used by the operating system to manage tasks.
### 207. Which of the following contains all the task and their status?
1. Register
2. Ready list
3. Access list
4. Task list
Show me the answer
**Answer:** 2. Ready list
**Explanation:**
* The **ready list** contains all the tasks that are ready to be executed, along with their status. The operating system uses this list to determine which task to run next.
### 208. Which determines the sequence and the associated task’s priority?
1. Scheduling algorithm
2. Ready list
3. Task control-block
4. Application register
Show me the answer
**Answer:** 1. Scheduling algorithm
**Explanation:**
* The **scheduling algorithm** determines the sequence in which tasks are executed and their associated priorities. Common algorithms include Round Robin, Priority Scheduling, and First-Come-First-Served (FCFS).
### 209. Which of the following can be used to refer to entities within the RTOS?
1. Threads
2. Kernels
3. System
4. Applications
Show me the answer
**Answer:** 1. Threads
**Explanation:**
* In a **Real-Time Operating System (RTOS)**, **threads** are used to refer to entities that execute independently. Threads share the same memory space but have their own stack and program counter.
### 210. Which of the following defines the set of instructions loaded into the memory?
1. Process
2. Task
3. Thread
4. System hardware
Show me the answer
**Answer:** 2. Task
**Explanation:**
* A **task** defines the set of instructions loaded into memory. It represents a unit of work that the operating system schedules and executes.
### 211. Which of the following uses its own address space?
1. Thread
2. Process
3. Task
4. Kernel
Show me the answer
**Answer:** 2. Process
**Explanation:**
* A **process** has its own **address space**, which includes memory allocated for code, data, and stack. This isolation ensures that processes do not interfere with each other.
### 212. Which of the following does not use a shared memory?
1. Process
2. Thread
3. Task
4. Kernel
Show me the answer
**Answer:** 1. Process
**Explanation:**
* **Processes** do not share memory with other processes. Each process has its own address space, while **threads** within the same process share memory.
### 213. Which of the following can own and control the resources?
1. Thread
2. Task
3. System
4. Peripheral
Show me the answer
**Answer:** 2. Task
**Explanation:**
* A **task** can own and control resources such as memory, files, and devices. The operating system manages resource allocation to tasks to ensure efficient execution.
### 214. Which can be supported if the task or process maintains a separate data area for each thread?
1. Single thread system
2. Mono thread system
3. Multiple threads
4. Dual threads
Show me the answer
**Answer:** 3. Multiple threads
**Explanation:**
* If a task or process maintains a **separate data area for each thread**, it can support **multiple threads**. This allows concurrent execution within the same process.
### 215. Which of the following possesses threads of execution?
1. Process
2. Thread
3. Kernel
4. Operating system
Show me the answer
**Answer:** 1. Process
**Explanation:**
* A **process** possesses **threads of execution**. Threads are lightweight units of execution within a process, sharing the same memory space but executing independently.
### 216. Which term is used to encompass more than a simple context switch?
1. Process
2. Single thread system
3. Thread
4. Multithread
Show me the answer
**Answer:** 1. Process
**Explanation:**
* The term **process** encompasses more than a simple context switch. It includes the entire execution environment, such as memory, files, and resources, whereas a context switch only involves saving and restoring the CPU state.
### 217. Which can be considered as the lower level in the multitasking operating system?
1. Process
2. Task
3. Threads
4. Multi threads
Show me the answer
**Answer:** 3. Threads
**Explanation:**
* **Threads** are considered the **lower level** in a multitasking operating system. They are lightweight and share the same memory space, making them more efficient than processes for concurrent execution.
### 218. Which of the following are the pin efficient method of communicating between other devices?
1. Serial port
2. Parallel port
3. Peripheral port
4. Memory port
Show me the answer
**Answer:** 1. Serial port
**Explanation:**
* **Serial ports** are **pin-efficient** because they use fewer wires (typically one or two) for communication compared to parallel ports, which require multiple wires for data transfer.
### 219. Which of the following depends the number of bits that are transferred?
1. Wait statement
2. Ready statement
3. Time
4. Counter
Show me the answer
**Answer:** 3. Time
**Explanation:**
* The **time** required for data transfer depends on the **number of bits** being transferred. For example, in serial communication, more bits take longer to transmit.
### 220. Which of the following is the most commonly used buffer in the serial porting?
1. LIFO
2. FIFO
3. FILO
4. LILO
Show me the answer
**Answer:** 2. FIFO
**Explanation:**
* **FIFO (First-In-First-Out)** buffers are commonly used in serial communication. They ensure that data is transmitted in the order it was received, which is essential for reliable communication.
### 221. What does SPI stand for?
1. Serial parallel interface
2. Serial peripheral interface
3. Sequential peripheral interface
4. Sequential port interface
Show me the answer
**Answer:** 2. Serial peripheral interface
**Explanation:**
* **SPI** stands for **Serial Peripheral Interface**. It is a synchronous serial communication protocol used for short-distance communication between microcontrollers and peripheral devices.
### 222. Which allows the full duplex synchronous communication between the master and the slave?
1. SPI
2. Serial port
3. I2C
4. Parallel port
Show me the answer
**Answer:** 1. SPI
**Explanation:**
* **SPI** allows **full-duplex synchronous communication** between a master and a slave device. This means data can be transmitted and received simultaneously on separate lines.
### 223. Which of the following processor uses SPI for interfacing?
1. 8086
2. 8253
3. 8254
4. MC68HC11
Show me the answer
**Answer:** 4. MC68HC11
**Explanation:**
* The **MC68HC11** microcontroller uses **SPI** for interfacing with peripheral devices. SPI is commonly used in embedded systems for high-speed communication.
### 224. In which register does the data is written in the master device?
1. Index register
2. Accumulator
3. SPDR
4. Status register
Show me the answer
**Answer:** 3. SPDR
**Explanation:**
* In SPI communication, data is written to the **SPDR (Serial Peripheral Data Register)** in the master device. This register holds the data to be transmitted or received.
### 225. What happens when 8 bits are transferred in the SPI?
1. Wait statement
2. Ready statement
3. Interrupt
4. Remains unchanged
Show me the answer
**Answer:** 3. Interrupt
**Explanation:**
* When **8 bits** are transferred in SPI, an **interrupt** is typically generated to signal the completion of the transfer. This allows the CPU to handle the next steps in the communication process.
### 226. Which signal is used to select the slave in the serial peripheral interfacing?
1. Slave select
2. Master select
3. Interrupt
4. Clock signal
Show me the answer
**Answer:** 1. Slave select
**Explanation:**
* The **Slave Select (SS)** signal is used to select the slave device in SPI communication. It is active low, meaning the slave is selected when the signal is low.
### 227. How much time period is necessary for the slave to receive the interrupt and transfer the data?
1. 4 clock time period
2. 8 clock time period
3. 16 clock time period
4. 24 clock time period
Show me the answer
**Answer:** 2. 8 clock time period
**Explanation:**
* In SPI communication, it typically takes **8 clock time periods** for the slave to receive an interrupt and transfer the data. This corresponds to the transfer of one byte of data.
### 228. Which of the following allows a lower priority task to run despite the higher priority task is active and waiting to preempt?
1. Message queue
2. Message passing
3. Semaphore
4. Priority inversion
Show me the answer
**Answer:** 4. Priority inversion
**Explanation:**
* **Priority inversion** occurs when a lower-priority task is allowed to run while a higher-priority task is waiting. This can happen due to resource contention or improper scheduling.
### 229. What happens to the interrupts in an interrupt service routine?
1. Disable interrupt
2. Enable interrupts
3. Remains unchanged
4. Ready state
Show me the answer
**Answer:** 1. Disable interrupt
**Explanation:**
* In an **Interrupt Service Routine (ISR)**, interrupts are typically **disabled** to prevent nested interrupts and ensure that the ISR completes without interruption.
### 230. Which of the following is a part of RTOS kernel?
1. Memory
2. Input
3. ISR
4. Register
Show me the answer
**Answer:** 3. ISR
**Explanation:**
* The **ISR (Interrupt Service Routine)** is a part of the **RTOS kernel**. It handles interrupts and ensures timely response to external events in real-time systems.
### 231. Which of the following is an industrial interconnection bus?
1. Bus interface unit
2. Data bus
3. Address bus
4. VMEbus
Show me the answer
**Answer:** 4. VMEbus
**Explanation:**
* The **VMEbus (Versa Module Eurocard bus)** is an industrial interconnection bus used for connecting multiple devices in industrial and embedded systems. It provides high-speed data transfer and modularity.
### 232. Which of the following supports seven interrupt priority level?
1. Kernel
2. Operating system
3. VMEbus
4. Data bus
Show me the answer
**Answer:** 3. VMEbus
**Explanation:**
* The **VMEbus** supports **seven interrupt priority levels**, allowing for efficient handling of multiple interrupts in industrial and embedded systems.
### 233. Which allows the parallel development of the hardware and software in the simulation?
1. High-level language simulation
2. Low-level language simulation
3. CPU simulator
4. Onboard simulator
Show me the answer
**Answer:** 1. High-level language simulation
**Explanation:**
* **High-level language simulation** allows for the **parallel development** of hardware and software. It enables developers to test and debug software before the hardware is available.
### 234. Which of the following are used to test the software?
1. Data entity
2. Data entry
3. Data table
4. Data book
Show me the answer
**Answer:** 3. Data table
**Explanation:**
* **Data tables** are used to test software by providing input data and expected output values. They help verify the correctness of the software under different conditions.
### 235. Which allows the UNIX software to be ported using a simple recomputation?
1. pSOS+
2. UNIX compatible library
3. pSOS+m
4. pOS+kernel
Show me the answer
**Answer:** 2. UNIX compatible library
**Explanation:**
* A **UNIX compatible library** allows UNIX software to be ported to other systems with minimal changes. It provides a consistent API for software development across different platforms.
### 236. Which of the following can simulate the processor, memory, and peripherals?
1. Input simulator
2. Peripheral simulator
3. Memory simulator
4. CPU simulator
Show me the answer
**Answer:** 4. CPU simulator
**Explanation:**
* A **CPU simulator** can simulate the processor, memory, and peripherals. It is used to test and debug software in a virtual environment before deploying it on actual hardware.
### 237. How many categories are there for the low-level simulation?
1. 2
2. 3
3. 4
4. 5
Show me the answer
**Answer:** 1. 2
**Explanation:**
* Low-level simulation is typically divided into **two categories**:
1. **Instruction-level simulation:** Simulates the execution of individual instructions.
2. **Cycle-level simulation:** Simulates the behavior of the system at each clock cycle.
### 238. How many categories are there for the low-level simulation?
1. 2
2. 3
3. 4
4. 5
Show me the answer
**Answer:** 1. 2
**Explanation:**
* Low-level simulation is typically divided into **two categories**:
1. **Cycle-accurate simulation:** Simulates the exact behavior of hardware at each clock cycle.
2. **Event-driven simulation:** Simulates hardware behavior based on events (e.g., signal changes).
### 239. Which of the following can simulate the LCD controllers and parallel ports?
1. Memory simulator
2. SDS
3. Input simulator
4. Output tools
Show me the answer
**Answer:** 2. SDS
**Explanation:**
* **SDS (System Design Simulator)** is a tool that can simulate **LCD controllers** and **parallel ports**. It provides a detailed simulation of hardware components for testing and debugging.
### 240. Which of the following provides a low-level method of debugging software?
1. High-level simulator
2. Low-level simulator
3. Onboard debugger
4. CPU simulator
Show me the answer
**Answer:** 3. Onboard debugger
**Explanation:**
* An **onboard debugger** provides a **low-level method of debugging software** by allowing direct access to hardware registers, memory, and signals. It is commonly used in embedded systems development.
### 241. Which of the following has the ability to download code using a serial port?
1. CPU simulator
2. High-level language simulator
3. Onboard debugger
4. Low-level language simulator
Show me the answer
**Answer:** 3. Onboard debugger
**Explanation:**
* An **onboard debugger** can **download code** to the target system using a **serial port**. This is useful for programming and debugging embedded systems.
### 242. What does the processor fetches from the EPROM if the board is powered?
1. Reset vector
2. Ready vector
3. Start vector
4. Acknowledge vector
Show me the answer
**Answer:** 1. Reset vector
**Explanation:**
* When a board is powered, the processor fetches the **reset vector** from the **EPROM**. The reset vector contains the address of the first instruction to execute after a reset.
### 243. Which of the following device can transfer the vector table from the EPROM?
1. ROM
2. RAM
3. CPU
4. Peripheral
Show me the answer
**Answer:** 3. CPU
**Explanation:**
* The **CPU** is responsible for transferring the **vector table** from the **EPROM** to memory during system initialization. The vector table contains addresses of interrupt handlers and other critical routines.
### 244. Which of the following allows the reuse of the software and the hardware components?
1. Platform based design
2. Memory design
3. Peripheral design
4. Input design
Show me the answer
**Answer:** 1. Platform based design
**Explanation:**
* **Platform-based design** allows the reuse of **software and hardware components** by providing a standardized framework. This reduces development time and cost.
### 245. Which of the following is the design in which both the hardware and software are considered during the design?
1. Platform based design
2. Memory based design
3. Software/hardware codesign
4. Peripheral design
Show me the answer
**Answer:** 3. Software/hardware codesign
**Explanation:**
* **Software/hardware codesign** is a design approach where both **hardware and software** are considered together during the design process. This ensures optimal performance and resource utilization.
### 246. What does API stand for?
1. Address programming interface
2. Application programming interface
3. Accessing peripheral through interface
4. Address programming interface
Show me the answer
**Answer:** 2. Application programming interface
**Explanation:**
* **API** stands for **Application Programming Interface**. It provides a set of functions and protocols for building software applications, enabling interaction between different software components.
### 247. Which activity is concerned with identifying the task at the final embedded systems?
1. High-level transformation
2. Compilation
3. Scheduling
4. Task-level concurrency management
Show me the answer
**Answer:** 4. Task-level concurrency management
**Explanation:**
* **Task-level concurrency management** involves identifying and managing tasks in embedded systems to ensure efficient execution and resource utilization.
### 248. In which design activity, the loops are interchangeable?
1. Compilation
2. Scheduling
3. High-level transformation
4. Hardware/software partitioning
Show me the answer
**Answer:** 3. High-level transformation
**Explanation:**
* **High-level transformation** involves optimizing the design at the algorithmic level, where loops and other structures can be **interchanged** to improve performance.
### 249. Which design activity helps in the transformation of the floating point arithmetic to a fixed point arithmetic?
1. High-level transformation
2. Scheduling
3. Compilation
4. Task-level concurrency management
Show me the answer
**Answer:** 1. High-level transformation
**Explanation:**
* **High-level transformation** includes converting **floating-point arithmetic** to **fixed-point arithmetic** to optimize performance and reduce resource usage in embedded systems.
### 250. Which design activity is in charge of mapping operations to hardware?
1. Scheduling
2. High-level transformation
3. Hardware/software partitioning
4. Compilation
Show me the answer
**Answer:** 3. Hardware/software partitioning
**Explanation:**
* **Hardware/software partitioning** is responsible for **mapping operations** to either hardware or software components to achieve the best performance and efficiency.
### 251. Which of the following is approximated during hardware/software partitioning, during task level concurrency management?
1. Scheduling
2. Compilation
3. Task-level concurrency management
4. High-level transformation
Show me the answer
**Answer:** 1. Scheduling
**Explanation:**
* **Scheduling** is approximated during **hardware/software partitioning** and **task-level concurrency management** to ensure that tasks are executed efficiently and meet timing constraints.
### 252. Which of the following is a process of analyzing the set of possible designs?
1. Design space exploration
2. Scheduling
3. Compilation
4. Hardware/software partitioning
Show me the answer
**Answer:** 1. Design space exploration
**Explanation:**
* **Design space exploration** is the process of analyzing and evaluating different design options to find the best solution that meets performance, cost, and power requirements.
### 253. Which of the following is a meet-in-the-middle approach?
1. Peripheral based design
2. Platform based design
3. Memory based design
4. Processor design
Show me the answer
**Answer:** 2. Platform based design
**Explanation:**
* **Platform-based design** uses a **meet-in-the-middle approach**, where predefined hardware and software platforms are used to accelerate the design process while allowing customization.
### 254. A software program that serves as an interface between the user of a computer and computer hardware is called
1. Application software
2. Utility system
3. Compiler
4. Operating system
Show me the answer
**Answer:** 4. Operating system
**Explanation:**
* An **operating system (OS)** is a software program that acts as an interface between the user and the computer hardware. It manages hardware resources and provides services to applications.
### 255. Which of the following was the first single user command based operating system (OS) for PC?
1. Windows 9X
2. VMS
3. Windows 95
4. PC-DOS
Show me the answer
**Answer:** 4. PC-DOS
**Explanation:**
* **PC-DOS (Personal Computer Disk Operating System)** was the first single-user, command-based operating system for PCs. It was developed by Microsoft for IBM PCs.
### 256. Which of the following is/are multitasking operating system?
1. Linux
2. Unix
3. Windows 95
4. All of the above
Show me the answer
**Answer:** 4. All of the above
**Explanation:**
* **Linux**, **Unix**, and **Windows 95** are all **multitasking operating systems**. They allow multiple tasks or processes to run concurrently, improving system efficiency.
### 257. Which of the following operating system is responsible for scheduling tasks according to priority and resource required?
1. Time Sharing Operating System
2. Real time Operating System
3. Multi User Operating System
4. Batch Processing Operating System
Show me the answer
**Answer:** 2. Real time Operating System
**Explanation:**
* A **Real-Time Operating System (RTOS)** is responsible for **scheduling tasks** based on priority and resource requirements to ensure timely execution of critical tasks.
### 258. Which of the following is a batch processing operating system?
1. Linux
2. VMS
3. Unix
4. Mac OS
Show me the answer
**Answer:** 3. Unix
**Explanation:**
* **Unix** is a **batch processing operating system** that allows users to submit jobs (batches of tasks) to be executed without user interaction.
### 259. Which of the following is also known as Command Line Interface (CLI)?
1. Character User Interface
2. Command User Interface
3. Command User Intercom
4. None of these
Show me the answer
**Answer:** 1. Character User Interface
**Explanation:**
* A **Command Line Interface (CLI)** is also known as a **Character User Interface (CUI)**. It allows users to interact with the system by typing text-based commands.
### 260. Microsoft Windows operating system is . . . . and . . . .
1. Multitasking, Multiuser
2. Multiuser, Single tasking
3. Single user, Multitasking
4. Single user, Single tasking
Show me the answer
**Answer:** 3. Single user, Multitasking
**Explanation:**
* **Microsoft Windows** is a **single-user, multitasking** operating system. It allows one user to run multiple applications simultaneously.
### 261. The process which is used to load the operating system in the memory of computer is called
1. Processing
2. Booting
3. Starting
4. Synchronizing
Show me the answer
**Answer:** 2. Booting
**Explanation:**
* **Booting** is the process of loading the operating system into the computer's memory and starting its execution. It initializes the hardware and prepares the system for use.
### 262. Which program is typically stored in ROM (read only memory) of a computer system?
1. Application program
2. Operating system program
3. Bootstrap program
4. Both b and c
Show me the answer
**Answer:** 3. Bootstrap program
**Explanation:**
* The **bootstrap program** is stored in **ROM** and is responsible for loading the operating system into memory during the boot process.
### 263. The process of choosing a task among several tasks in the pool and loading it into the main memory, is
1. Single processing
2. Job scheduling
3. Single programming
4. Single tasking
Show me the answer
**Answer:** 2. Job scheduling
**Explanation:**
* **Job scheduling** is the process of selecting a task from a pool of tasks and loading it into the main memory for execution. It ensures efficient use of system resources.
### 264. What is the full form of POST?
1. Power On Self Test
2. Power Off Self Test
3. Power On/Off Self Test
4. None
Show me the answer
**Answer:** 1. Power On Self Test
**Explanation:**
* **POST** stands for **Power On Self Test**. It is a diagnostic process performed by the computer during startup to check the hardware components and ensure they are functioning correctly.
### 265. The \_\_\_\_\_\_ Operating System pays more attention to the meeting of the time limits.
1. Network
2. Distributed
3. Online
4. Real-time
Show me the answer
**Answer:** 4. Real-time
**Explanation:**
* A **Real-Time Operating System (RTOS)** is designed to meet strict **time limits** for task execution. It ensures that critical tasks are completed within their deadlines.
### 266. The interrupt latency should be \_\_\_\_\_\_ for real time operating systems.
1. Maximum
2. Minimal
3. Dependent on the scheduling
4. Zero
Show me the answer
**Answer:** 2. Minimal
**Explanation:**
* **Interrupt latency** in a **Real-Time Operating System (RTOS)** should be **minimal** to ensure that critical tasks are handled promptly and deadlines are met.
### 267. The Time duration required for scheduling dispatcher to stop one process and start another is called...
1. Dispatch latency
2. Process latency
3. Interrupt latency
4. Execution latency
Show me the answer
**Answer:** 1. Dispatch latency
**Explanation:**
* **Dispatch latency** is the time required for the **scheduler** to stop one process and start another. It is a critical factor in the performance of multitasking systems.
### 268. Which single task of a particular application is process is a type of processor...
1. Applicant processor
2. One task processor
3. Real Time processor
4. Dedicated processor
Show me the answer
**Answer:** 4. Dedicated processor
**Explanation:**
* A **dedicated processor** is designed to handle a **single task** or a specific application. It is optimized for performance and efficiency in that particular task.
### 269. Which one of the following is a real time operating system?
1. RTLinux
2. VxWorks
3. Windows CE
4. All of the mentioned
Show me the answer
**Answer:** 4. All of the mentioned
**Explanation:**
* **RTLinux**, **VxWorks**, and **Windows CE** are all examples of **Real-Time Operating Systems (RTOS)**. They are designed to handle tasks with strict timing requirements.