Threads MCQ

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• What is the output for the below code?<br><pre><code class="java">class A implements Runnable{ public void run(){ System.out.println(Thread.currentThread().getName()); }}public class Test{ public static void main(String... args){ A a = new A(); Thread t = new Thread(a); t.setName("good"); t.start(); }}</code></pre>
  ক

  good

  খ

  null

  গ

  Compilation fails with an error at line 5

  ঘ

  Compilation succeed but Runtime Exception

  ঙ

  None of these
• Which keyword when applied on a method indicates that only one thread should execute the method at a time.
  ক

  volatile

  খ

  synchronized

  গ

  native

  ঘ

  static

  ঙ

  final
• What notifyAll() method do?
  ক

  Wakes up one threads that are waiting on this object's monitor

  খ

  Wakes up all threads that are not waiting on this object's monitor

  গ

  Wakes up all threads that are waiting on this object's monitor

  ঘ

  None of the above
• Which of the following are methods of the Thread class?<br>1) yield()<br>2) sleep(long msec)<br>3) go()<br>4) stop()
  ক

  1 , 2 and 4

  খ

  1 and 3

  গ

  3 only

  ঘ

  None of the above
• Predict the output:<br><pre><code class="java">class A implements Runnable{ public void run(){ try{ for(int i=0;i</code></pre>
  ক

  A A A A B B B B

  খ

  A B A B A B A B

  গ

  Output order is not guaranteed

  ঘ

  Compilation succeed but Runtime Exception

  ঙ

  None of these
• What will happen after compiling and running following code?<br><pre><code class="java">class A implements Runnable{ public void run(){ System.out.println("run-a"); }}public class Test{ public static void main(String... args){ A a = new A(); Thread t = new Thread(a); t.start(); t.start(); }}</code></pre>
  ক

  run-a

  খ

  run-a run-a

  গ

  Compilation fails with an error at line 6

  ঘ

  Compilation succeed but Runtime Exception

  ঙ

  None of these
• Analyze the following code:<br><pre><code class="java">public abstract class Test implements Runnable{ public void doSomething() { };}</code></pre>
  ক

  The program will not compile because it does not implement the run() method.

  খ

  The program will not compile because it does not contain abstract methods.

  গ

  The program compiles fine.

  ঘ

  None of the above
• Which of the following constructor of class Thread is valid one?
  ক

  Thread(Runnable threadOb, int priority)

  খ

  Thread(int priority)

  গ

  Thread(Runnable threadOb, String threadName)

  ঘ

  Thread(String threadName, int priority)

  ঙ

  None of these
• When a class extends the Thread class ,it should override ............ method of Thread class to start that thread.
  ক

  start()

  খ

  run()

  গ

  init()

  ঘ

  go()
• In java a thread can be created by ..........
  ক

  Extending the thread class.

  খ

  Implementing Runnable interface.

  গ

  Both of the above

  ঘ

  None of these
• In Java, what is the maximum thread priority value?
  ক

  100

  খ

  255

  গ

  1000

  ঘ

  10
• What is the purpose of the getState() method in Java threads?
  ক

  It suspends a thread

  খ

  It starts a new thread

  গ

  It retrieves the current state of a thread

  ঘ

  It sets the state of a thread
• In Java, can you directly access the run() method of a Thread object?
  ক

  Only if the thread is marked as "final"

  খ

  Yes, but it will execute in the current thread, not as a separate thread

  গ

  Only if the thread is marked as "static"

  ঘ

  Only if the thread is marked as "final"
• What is the purpose of the setPriority() method in Java threads?
  ক

  It starts a new thread

  খ

  It resumes a paused thread

  গ

  It sets the priority of a thread

  ঘ

  It synchronizes threads
• In Java, which class is used to create and manage thread groups?
  ক

  GroupManager

  খ

  ThreadController

  গ

  ThreadManager

  ঘ

  ThreadGroup
• How can you handle exceptions in Java threads?
  ক

  By using try-catch blocks within the run() method

  খ

  By using the stop() method

  গ

  By ignoring exceptions in threads

  ঘ

  By using the yield() method
• In Java, what is the purpose of the isInterrupted() method in threads?
  ক

  It checks if a thread is a daemon thread

  খ

  It checks if a thread is waiting

  গ

  It checks if a thread is running

  ঘ

  It checks if a thread has been interrupted
• What is the result of calling the setDaemon(true) method on a running thread in Java?
  ক

  It resumes the thread

  খ

  It pauses the thread

  গ

  It sets the thread as a daemon thread

  ঘ

  It stops the thread immediately
• In Java, what happens when a thread encounters an uncaught exception and terminates abruptly?
  ক

  The thread is paused indefinitely

  খ

  The JVM prints the exception trace and terminates the thread

  গ

  The thread resumes execution without any impact

  ঘ

  The thread is paused indefinitely
• What is the purpose of the isDaemon() method in Java threads?
  ক

  It checks if a thread is currently running

  খ

  It checks if a thread is sleeping

  গ

  It checks if a thread is a daemon thread

  ঘ

  It checks if a thread is waiting
• How can you prevent multiple threads from accessing a critical section of code simultaneously in Java?
  ক

  By using the wait() method

  খ

  By using the start() method multiple times

  গ

  By creating more threads to access the critical section

  ঘ

  By using synchronized blocks or methods
• In Java, what is a daemon thread?
  ক

  A thread that runs in the background and does not prevent the program from exiting

  খ

  A thread that is always in a waiting state

  গ

  A thread that cannot be interrupted

  ঘ

  A thread that runs on a separate CPU
• Which keyword is used to declare a synchronized method in Java?
  ক

  sync

  খ

  lock

  গ

  thread-safe

  ঘ

  synchronized
• In Java, what is the purpose of the interrupt() method in threads?
  ক

  It resumes the thread

  খ

  It pauses the thread

  গ

  It interrupts the normal execution of a thread, causing it to throw an InterruptedException

  ঘ

  It stops the thread permanently
• What is the purpose of the yield() method in Java threads?
  ক

  It suspends the current thread indefinitely

  খ

  It suggests that the current thread should yield to other threads with the same priority

  গ

  It sets the priority of the current thread

  ঘ

  It suspends the current thread indefinitely
• In Java, can you force a thread to stop its execution using the stop() method?
  ক

  No, the stop() method is deprecated and cannot be used

  খ

  Only if the thread is marked as "final"

  গ

  Yes, but it is discouraged because it can leave the program in an inconsistent state

  ঘ

  Only if the thread is marked as "static"
• How can you check if a thread is still running in Java?
  ক

  By using the runStatus() method

  খ

  By using the isThreadAlive() method

  গ

  By using the isRunning() method

  ঘ

  By using the isAlive() method
• In Java, what is the difference between a thread's priority and its thread group's maximum priority?
  ক

  A thread's priority determines its relative importance, while the thread group's maximum priority sets an upper limit on thread priorities

  খ

  A thread's priority is always higher than the thread group's maximum priority

  গ

  A thread's priority is the same as the thread group's maximum priority

  ঘ

  A thread's priority is unrelated to the thread group's maximum priority
• What is a deadlock in multithreading?
  ক

  A situation where a thread runs indefinitely without blocking

  খ

  A situation where all threads complete successfully

  গ

  A situation where a thread is terminated forcibly

  ঘ

  A situation where two or more threads are unable to proceed because they are each waiting for the other to release a resource
• What is the purpose of the join() method in Java threads?
  ক

  It synchronizes threads

  খ

  It resumes a paused thread

  গ

  It waits for a thread to complete its execution before moving on

  ঘ

  It starts a new thread