40+ National English Medium School & Jr. College Interview Questions and Answers

If the permission for a file is 000 in UNIX, then the file cannot be accessed by anyone.

• File with permission 000 is not accessible to anyone, including the owner, group, and others.

• The file cannot be read, written, or executed with permission 000.

• To change the permissions and make the file accessible, the owner or superuser needs to modify the permissions using the chmod command.

The code will result in an error because 'case(2)' is not a valid syntax in a switch statement.

• Correct syntax for switch statement is 'case 1:' not 'case(1)'

• Each case should be followed by a colon (:) not parentheses

• The 'break' statement is missing after 'printf("default");'

To print TATA alone from TATA POWER using string copy and concatenate commands in C, we can use string copy to copy the first four characters and then concatenate a null character at the end.

• Use strncpy to copy the first four characters of the string TATA POWER into a new string.

• Add a null character at the end of the new string to terminate it.

• Print the new string containing only TATA.

Memory sharing is fast in message passing.

• Memory sharing allows for direct access to shared data without the need for message passing overhead.

• Examples of memory sharing include shared memory systems in parallel computing.

• Memory sharing can lead to potential issues such as race conditions and data inconsistency.

The output of the code will be 4.

• The expression x=x----1 is equivalent to x = x - (-1) = x + 1.

• Therefore, x will be 5 + 1 = 6.

• But since the post-decrement operator is used, the final value of x will be 6 - 1 = 5.

Context switching takes place when the CPU switches from one process to another process.

• Context switching involves saving the state of the current process and loading the state of the next process.

• It can occur when a process voluntarily yields the CPU, or when a higher priority process preempts the current process.

• Examples include multitasking operating systems where multiple processes share the CPU.

• Context switching overhead can impact system performance.

Memory management in Java involves automatic garbage collection, heap and stack memory allocation.

• Java uses automatic garbage collection to manage memory by deallocating objects that are no longer in use.

• Memory in Java is divided into two main areas - heap memory for objects and stack memory for method calls and local variables.

• Java provides methods like System.gc() to suggest garbage collection, but it's ultimately up to the JVM to decide when to run it.

The finalize function is used in Java to perform cleanup operations before an object is garbage collected.

• Finalize method is called by the garbage collector before reclaiming an object's memory.

• It is not recommended to rely on finalize for resource cleanup as it is not guaranteed to be called.

• Example: public void finalize() { // cleanup code }

Different types of joins in SQL are inner join, left join, right join, and full outer join.

• Inner join: Returns rows when there is a match in both tables

• Left join: Returns all rows from the left table and the matched rows from the right table

• Right join: Returns all rows from the right table and the matched rows from the left table

• Full outer join: Returns rows when there is a match in either table