Mock Interview Questions

What is the primary function of an operating system?

What are the different types of operating systems?

What is process management in an operating system?

What is memory management in an operating system?

What is file system management in an operating system?

What is the difference between a process and a thread?

What is synchronization in an operating system?

What is deadlock in an operating system?

What is starvation in an operating system?

What is priority scheduling in an operating system?

What is round-robin scheduling in an operating system?

What is first-come-first-served scheduling in an operating system?

What is shortest job first scheduling in an operating system?

What is multithreading in an operating system?

What is virtual memory in an operating system?

What is paging in an operating system?

What is segmentation in an operating system?

What is cache memory in an operating system?

What is the difference between a monolithic kernel and a microkernel?

What is the purpose of a device driver in an operating system?

Write a program to simulate a simple operating system scheduler that uses first-come-first-served scheduling.

public class Scheduler {
  public static void main(String[] args) {
    
    int[] processes = {
      1, 2, 3, 4, 5}
      ;
      for (int i = 0;
      i < processes.length;
      i++) {
        
        System.out.println("Process " + processes[i] + " is executing");
      }
    }
  }

Write a program to simulate a simple operating system that uses round-robin scheduling with a time quantum of 2.

public class RoundRobinScheduler {
  public static void main(String[] args) {
    
    int[] processes = {
      1, 2, 3, 4, 5}
      ;
      int timeQuantum = 2;
      for (int i = 0;
      i < processes.length;
      i++) {
        
        System.out.println("Process " + processes[i] + " is executing for " + timeQuantum + " units");
      }
    }
  }

Write a program to simulate a simple operating system that uses priority scheduling with two priority levels.

public class PriorityScheduler {
  public static void main(String[] args) {
    
    int[] highPriorityProcesses = {
      1, 2}
      ;
      int[] lowPriorityProcesses = {
        3, 4, 5}
        ;
        for (int i = 0;
        i < highPriorityProcesses.length;
        i++) {
          
          System.out.println("High-priority process " + highPriorityProcesses[i] + " is executing");
        }
        for (int i = 0;
        i < lowPriorityProcesses.length;
        i++) {
          
          System.out.println("Low-priority process " + lowPriorityProcesses[i] + " is executing");
        }
      }
    }

Write a program to simulate a simple operating system that uses multithreading with two threads.

public class MultithreadedOS {
  public static void main(String[] args) {
    
    Thread thread1 = new Thread(new Runnable() {
      
      public void run() {
        
        System.out.println("Thread 1 is executing");
      }
    }
  );
  Thread thread2 = new Thread(new Runnable() {
    
    public void run() {
      
      System.out.println("Thread 2 is executing");
    }
  }
);
thread1.start();
thread2.start();
}
}

Write a program to simulate a simple operating system that uses virtual memory with a page size of 4KB.

public class VirtualMemoryOS {
  public static void main(String[] args) {
    
    int pageSize = 4096;
    int[] pages = new int[10];
    for (int i = 0;
    i < pages.length;
    i++) {
      
      System.out.println("Page " + i + " is loaded into memory");
    }
  }
}

Write a program to simulate a simple operating system that uses a cache with a size of 16KB.

public class CacheOS {
  public static void main(String[] args) {
    
    int cacheSize = 16384;
    int[] cache = new int[cacheSize];
    for (int i = 0;
    i < cache.length;
    i++) {
      
      System.out.println("Cache entry " + i + " is accessed");
    }
  }
}

Write a program to simulate a simple operating system that uses a file system with two files.

public class FileSystemOS {
  public static void main(String[] args) {
    
    String[] files = {
      "file1.txt", "file2.txt"}
      ;
      for (int i = 0;
      i < files.length;
      i++) {
        
        System.out.println("File " + files[i] + " is accessed");
      }
    }
  }

Write a program to simulate a simple operating system that uses a device driver to interact with a hardware device.

public class DeviceDriverOS {
  public static void main(String[] args) {
    
    System.out.println("Device driver is initialized");
    System.out.println("Device driver is interacting with hardware device");
  }
}