Questions

'Rare earth'(They are all metals)

Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. 

These are actually made to replace floppy disks that were used to store files and programs from the computer.

The format was originally developed to store and play only sound recordings but was later adapted for storage of data (CD-ROM).ese CD's uses Laser technology.

Entrepreneurship as a theory of business was propounded by Joseph. A. Schumpeter.

Schumpeter’s Innovation Theory of Profit :

Definition:  The Innovation Theory of Profit was proposed by Joseph. A. Schumpeter, who believed that an entrepreneur can earn economic profits by introducing successful innovations.

The ball with which Table Tennis is played is called Ping Pong Ball.

According to the International rules, the diameter of the ping pong ball must be not less than 39.5 millimeters and not greater than 40.5  millimeters having a mass of 2.7 grams.

Gujrat