Question Discussion & Solution

The correct answer is Boy pushing wall in a room.

Key Points

• Boy pushing the wall in the room is not an example of work done.
  • When a boy pushes a wall, he is applying force on the wall. We see that the wall shows no displacement.
  • Work is given as the product of the forces and the displacement in the same direction.
  • Hence the work done is zero.

Additional Information

• Work is done when a force moves. Everyday examples of work include walking up a flight of stairs, lifting heavy objects, pulling a sled and pushing a shopping trolley, Applying pressure on a pebble lying on the surface, raising a book to a height.
  • Work is not done when holding a bag stationary or a book at arm's length because although a force is being applied, the force does not move.

There are 4 library functions provided by C defined under header file to facilitate dynamic memory allocation in C programming. They are:

• malloc()
• calloc()
• free()
• realloc()

Here the pattern is,

0.15552 ÷ 0.3 = 0.5184,

0.5184 ÷ 0.3 = 1.728,

1.728 ÷ 0.3 = 5.76,

Similarly, we have :

5.76 ÷ 0.3 = 19.2

Eagle, Bird, Crocodile

All Eagle is the Bird and Crocodile is the reptile. 

So,  Venn diagram given bellow-

Hence, option 4 is the correct answer.

Malware Protection is not the main function of the operating system.

Important Points

• Malware Protection
  • Malware is any software intentionally designed to cause damage to a computer, server, client, or computer network.
  • A range of antivirus software, firewalls and other strategies are used to protect against the introduction of malware.

Key Points

• Operating system
  • An operating system is a large and complex system.
  • OS system components include:
    • File,
    • Process,
    • Memory,
    • I/O device management.

 Additional Information

• The process management component
  • The process management component is a procedure for managing the many processes that are running simultaneously on the operating system.
  • Every software application program has one or more processes when they are running.
  • For example, when we use a browser like Google Chrome, there is a process running for that browser program.
  • All these processes managed by process management. 
  • The process management uses memory allocated to them and shutting them down when needed.
• File management
  • File management in an operating system includes file creation and deletion.
  • Manipulating files and directories.
• Memory management
  • ​An Operating System performs the functions for Memory Management such as:
    • It helps to keep track of primary memory.
    • Determine what parts of it are in use by whom, what part is not in use.
• I/O device management
  • ​An Operating System performs the functions for I/O device management such as:
    • It offers buffer caching system
    • It provides general device driver code
    • It provides drivers for particular hardware devices.