Question Discussion & Solution

The correct answer is F2.

Key Points

• F2 function key is used to edit the content of a cell in MS-Excel.
• To enter Edit mode, we can follow any of these steps:
  • Double-click the cell that contains the data that you want to edit.
  • Click the cell that contains the data that you want to edit, and then click anywhere in the formula bar.
  • Click the cell that contains the data that you want to edit, and then press F2.

Additional Information

Some important shortcuts used in MS Excel:

• Ctrl + N Create a new workbook.
• Ctrl + O Open an existing workbook.
• Ctrl + S Save the active workbook.
• F12 Save the active workbook under a new name, displays the Save as dialog box.
• Ctrl + W Close the active workbook.
• Ctrl + C Copy the contents of the selected cells to Clipboard.
• Ctrl + X Cut the contents of the selected cells to Clipboard.
• Ctrl + V Insert the contents of the Clipboard into the selected cell(s).

The variable is the basic unit of storage in a Java program. A variable is defined by the combination of an identifier, a type, and an optional initializer.

Variable names cannot be keyword, it is case- sensitive and the first character must be a letter.

In Java, all variables must be declared before they can be used. The basic form of a variable declaration is:

type identifier [ = value ][, identifier [= value ] …];

Examples:

int a, b;

int a = 10, b = 20, c = 30;

int a, b = 20, c;

Confusion point

In Java, variable name can also start with underscore character “_”, or a dollar sign “$”.

Best Possible answer is chosen.

The correct answer is Total Internal Reflection of Light.

Key Points

• Total Internal Reflection of Light
  • When a light ray, traveling from a denser medium towards a rarer medium is incident at the interface at an angle of incidence greater than the critical angle, then the rays are reflected back into the denser medium.
  • Practical Applications of Total Internal Reflection
  1. The working of optical fiber is based on total internal reflection.
  2. Mirage is formed due to total internal reflection.
  3. The brilliance of diamonds is mainly due to the total internal reflection of light inside them.

Additional Information

• Reflection of Light
  • The phenomenon of rebounding back of light rays in the same medium on striking a smooth surface is called reflection of light.
  • Silver metal is one of the best reflectors of light.
• Diffraction of Light
  • The phenomenon of bending of light around the corners and the spreading of light within the geometrical shadow of the opaque obstacles is called diffraction of light.
• Refraction of Light
  • Change in the path of a light ray as it passes from one medium to another is called refraction.

Ocean is the mass of water.

Similarly,

Desert is the mass of sand.

Information systems hardware is the part of an information system one can touch i.e. the physical components of the technology.

Computers, keyboards, disk drives, iPads, and flash drives are all examples of information systems hardware.