Question Discussion & Solution

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()

The correct answer is Hygrometer.

Key Points

• Hygrometer
  • A hygrometer is an instrument for measuring the relative humidity of the atmosphere.
  • The hygrometer was invented by Leonardo da Vinci.

Additional Information

• ​Barometer
  • A barometer is an instrument used to measure atmospheric pressure.
  • The barometer was invented by Torricelli.
• Hydrometer
  • A hydrometer is an instrument used to measure the specific gravity of liquids.
  • The hydrometer was invented by Nicholson.
• ​Anemometer
  • An anemometer is an instrument used to measure the velocity of wind and directions.
  • The anemometer was invented by Leon Alberti.

Y → Position value of Y is 25 which square of 5.

P → Position value of P is 16 which square of 4

I → Position value of I is 9 which square of 3

D → Position value of D is 4 which square of 2

Therefore, square of 1 is 1 and that corresponds to A.

Here the pattern is,

The correct answer is Single-User Operating System.

Important Points

• Single-User Operating System
  • Performs a single task for Single-user.
  • This operating system is designed to manage the computer so that one user can effectively do one thing at a time.
  • Examples include Microsoft Windows.

Additional Information

• The different types of Operating System:
• Batch Operating System
  • There is no direct communication between the computer and the OS.
  • There is an intermediate, the Operator.
  • The operator distributes the work into batches.
• Real-Time Operating System
  • The processing time is very small between the user’s command and the output such that there is no operator.
• Time-Sharing Operating System
  • Multiple people at various computers can use a program at the same time.
• Distributed Operating System
  • When two or more systems are connected to each other and one can open each other's files.
• Embedded Operating System
  • These special Operating systems are built into larger systems.
  • They are limited to single specific functions like an ATM.
• Network Operating System
  • They have one main server which is connected to other client servers.
  • It provides a secure operating system for working with multiple users.