Question Discussion & Solution

The correct answer is 1 megabyte.

Key Points

• Computer data storage conversions:

A number system includes the number of independent digits used in the number system (the base), the place values of the different digits constituting the number, and the maximum numbers that can be written with the given number of digits.

The Binary Number System: 

• The binary number system with only two independent digits, 0 and 1, is a base-2 number system.
• All larger binary numbers are represented in terms of ‘0’ and ‘1’.

Decimal to Binary Conversion:

Step 1: Divide 22 by 2 to get the Quotient. Keep the Whole part for the next step and set the Remainder aside.

25 / 2 = 12 with 1 remainder

Step 2: Divide the Whole part of the Quotient from Step 1 by 2. Again, keep the Whole part and set the Remainder aside.

12 / 2 = 6 with 0 remainder

Step 3: Repeat Step 2 above until the Whole part is 0.

6 / 2 = 3 with 0 remainder

3 / 2 = 1 with 1 remainder

1 / 2 = 0 with 1 remainder

Step 4: Write down the Remainders in reverse order to get the answer to 25 as a binary.

When we put the remainders together in reverse order, we get the answer 11001

Hence, the binary equivalent of decimal number 25 is 11001

Memory in a computer system is required for the storage and retrieval of the instructions and data. A system uses a variety of devices for storing the instructions and data that are required for its operation.

1. CPU registers - They are part of the control unit and ALU rather than the memory. Hence their contents can be handled much faster than any content of memory.

2. Cache Memory: It stores program instruction and data that the computer uses more frequently. The processor can access this information from the cache rather than having to get it from the computer’s main memory. Hence, it is faster than RAM.

3. Primary or main memories are used mainly for primary storage. It stores programs and data which are currently needed by the CPU. The primary memory is a static device. There is no rotating part in it. Examples include RAM, ROM, etc.

• Random Access Memory (RAM): It stores data that the computer needs to use temporarily. So it is faster than the secondary storage devices. It is a volatile memory i.e. the data disappear from it when the power is off. The amount of RAM in a computer system can affect a computer’s performance.
• Read-Only Memory (ROM): The system uses ROM to boot itself. It is used to store the start-up information of the computer. This is called non-volatile memory i.e. it retains its content even if the computer loses its power.

4. Secondary Memory: It is the storage that the CPU cannot access directly. Its content firstly needs to be copied into ram and then transferred to CPU. It stores data that can be easily retrieved only by the main memory and used by the processor. For example, hard disk.

Hence, the lists of computer memory types from lowest to highest speed are- 

Secondary Storage < Main Memory < Cache Memory

Therefore, Option 2 is the correct answer.

The correct answer is Versatility, Diligence.

Key Points

• Versatility is the characteristic of a computer to perform completely different types of work at the same time, whereas diligence makes it to work for hours without boredom or tiredness. 
• Versatility means the capacity of the computer of performing more than one task at the same time.
• Diligence is the capacity of the computer of performing repetitive tasks without getting tired.
• A computer is free from tiredness, lack of concentration, fatigue, etc therefore it can work for hours without creating any errors.

Additional Information

Characteristics of Computer System are:

• Speed - A computer works with much higher speed and accuracy compared to humans while performing mathematical calculations. 
• Accuracy - Computers perform calculations with 100% accuracy. 
• Diligence - A computer can perform millions of tasks or calculations with the same consistency and accuracy. 
• Versatility
• Reliability
• Memory

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).