CDAC Core Java Practice Questions

1. What is the error in the following code?
class Test { abstract void display( ); }

A. No error 

B. Method display( ) should be declared as static 

C. Test class should be declared as abstract 

D. Test class should be declared as public 

2. DataInput is :

A. an abstract class defined in java.io 

B. a class we can use to read primitive data types 

C. an interface that defines methods to open files 

D. an interface that defines methods to read primitive data types. 

3. which of the following tools is used to generate the stubs and skeletonsn for a remote service

A. javac 

B. rmic 

C. java 

D. rmiregistry 

4. how do objects pass messages in java ?

A. they pass messages by modifying each other`s fields 

B. they pass messages by modifying the static variables of each other`s classes 

C. they pass messages by calling each other`s instance methods 

D. they pass messages by calling static methods of each other`s classes 

5. How can you change the current working directory using an instance of the file class called FileName?

A. FileName.chdir(‘DirName’) 

B. FileName.cd(‘DirName’) 

C. FileName.cwd(‘DirName’) 

D. The file class doesnot support directly changing the current directory  

6. You can explicitly drop a object reference by setting the value of a variable whose data type is a reference type to ________

A. null 

B. NAN 

C. 0 

D. None of these 

7. Because finalize() belongs to the java.lang.Object, it is present in all ________

A. objects 

B. classes 

C. methods 

D. none of above 

8. Which of these is interface in the collection framework.Select the correct answers

A. Array 

B. Vector 

C. Linked List 

D. set 

9. under which circumstances will a thread stop?

A. the run() method that the thread stop 

B. the call to the start() method of the thraed is executing ends 

C. the suspend() method is called on the Thread object 

D. the wait() method is called on the Thread object 

10. what is the class name of the exception thrown by an assertion statement?

A. AssertionError 

B. FailedAssertion 

C. Error 

D. RuntimeException 

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