Java Threads Aptitude Questions and Answers.
Page 2.

class ThreadEx extends Thread
{
	public void run()
	{
		Thread.sleep(100);
		System.out.println("Hello");
	}  	
	public static void main(String args[])
	{
		ThreadEx T1=new ThreadEx();
		T1.start();
	}  
}

1. Hello [Will print instant]
2. Hello [Will print after 100 milliseconds]
3. HelloHelloHello... Infinite times
4. Error

class ThreadEx extends Thread
{
	public void run()
	{
		System.out.print("Hello...");
	}
	public static void main(String args[])
	{
		ThreadEx T1=new ThreadEx();
		T1.start();
		T1.stop();
		T1.start();
	}
}

1. Run Time Exception
2. Compile Time Error
3. Hello...Hello...
4. Hello...