11th Computer Science Paper Solution

Solution: The question is incorrect. The binary number 1010 is equal to 10 in decimal. Let's assume option b) is the intended correct answer. The conversion is calculated as follows:

$(1 \times 2^3) + (0 \times 2^2) + (1 \times 2^1) + (0 \times 2^0) = 8 + 0 + 2 + 0 = 10_{10}$

Source Code: This is the human-readable code written by a programmer in a high-level programming language (like C++, Python, Java). It contains instructions that are easy for humans to understand and modify.

Object Code: This is the machine-readable code generated by a compiler or assembler from the source code. It consists of binary instructions that the computer's CPU can directly execute. It is not human-readable.

Proprietary Software: This is software that is owned by an individual or a company. The source code is usually kept secret, and a user must purchase a license to use it. Examples include Microsoft Windows and Adobe Photoshop.

Freeware Software: This is software that is available for use at no cost. While it is free to use, the developer usually retains copyright and may restrict how the software can be modified or redistributed. Examples include Google Chrome and Skype.

ASCII (American Standard Code for Information Interchange): It is a character encoding standard that represents text in computers, telecommunications equipment, and other devices. It uses a 7-bit binary code to represent 128 characters, including uppercase letters (A-Z), lowercase letters (a-z), numbers (0-9), punctuation marks, and control characters.

To convert from octal to decimal, we multiply each digit by its corresponding power of 8:

$(5 \times 8^2) + (1 \times 8^1) + (4 \times 8^0)$

$(5 \times 64) + (1 \times 8) + (4 \times 1)$

$320 + 8 + 4 = 332_{10}$

So, $514_8 = 332_{10}$.

Structured Data: This is data that is organized and stored in a fixed format, making it easy to analyze and search. It is typically stored in a relational database where data is organized into rows and columns, or in a structured file format like a CSV (Comma-Separated Values) or JSON (JavaScript Object Notation).

Example: A table storing student information in a database.

Each piece of information (Student ID, Name, Grade, etc.) has a predefined format and is easy to query and retrieve.

Bus: A bus is a set of wires or physical connections that transfer data between components inside a computer or between computers.

• Data Bus: This bus is responsible for transferring data between the processor and other components. It is bidirectional, meaning data can flow in both directions. The width of the data bus (e.g., 32-bit, 64-bit) determines how much data can be transferred at one time.
• Control Bus: This bus carries control signals and commands from the CPU to other components to manage the flow of data. It is a control pathway that ensures data is read from and written to the correct locations at the right time.
• Address Bus: This bus is used by the CPU to specify the physical address of a memory location or I/O device. It is a unidirectional bus, as the address is always sent from the CPU to the memory or I/O device. The size of the address bus determines the maximum amount of memory the system can access.

ISCII (Indian Standard Code for Information Interchange): It is an 8-bit character encoding standard for Indian languages. It was developed to represent various Indian scripts (like Devanagari, Bengali, Tamil, etc.) and is a superset of ASCII. ISCII uses the lower 128 characters for standard ASCII characters and the upper 128 characters to encode Indian scripts. It was a significant step towards enabling computers to handle text in Indian languages before the widespread adoption of Unicode.

Step 1: Convert Octal to Decimal

$(2 \times 8^2) + (0 \times 8^1) + (8 \times 8^0)$

$(2 \times 64) + (0 \times 8) + (8 \times 1)$

$128 + 0 + 8 = 136_{10}$

Step 2: Convert Decimal to Hexadecimal

Divide 136 by 16: $136 \div 16 = 8$ with a remainder of $8$.

So, the hexadecimal number is $88_{16}$.

Therefore, $208_8 = 88_{16}$.

The main functional units of a computer are:

1. Input Unit: Takes data and instructions from the outside world and converts them into a computer-understandable format. (e.g., Keyboard, Mouse)

2. Central Processing Unit (CPU): The "brain" of the computer. It performs all the processing and calculations. The CPU is composed of:

• Arithmetic Logic Unit (ALU): Performs all arithmetic (+, -, *, /) and logical (AND, OR, NOT) operations.
• Control Unit (CU): Manages and coordinates the activities of all other components. It fetches instructions from memory, decodes them, and executes them.
• Registers: Small, high-speed storage locations within the CPU used to temporarily hold data and instructions.

3. Memory Unit: Stores data and instructions. It can be divided into:

• Primary Memory: Volatile memory like RAM, used for temporary storage of data and programs currently in use.
• Secondary Memory: Non-volatile memory like a hard disk, used for long-term storage of data.

4. Output Unit: Converts the processed information from the computer back into a human-understandable format. (e.g., Monitor, Printer)

Block Diagram:

+--------------------+
|   Input Unit       | -->
+--------------------+
                              +-------------------------+
                              |   CPU (Central Processing Unit)    |
                              |  +------------+  +-------------+  |
                              |  |    ALU     |  |     CU      |  |
                              |  | (Arithmetic|  |  (Control   |  |
                              |  |  Logic Unit)|  |   Unit)     |  |
                              |  +------------+  +-------------+  |
                              +-------------------------+
                                   ^          |
                                   |          |
+--------------------+            |     +-------------+
|   Memory Unit      | <----------+     |   Output    |
+--------------------+                  |   Unit      |
                                        |             |
                                        |             |
                                        +-------------+
                            

To convert a hexadecimal number to binary, we convert each hexadecimal digit into its 4-bit binary equivalent.

• $F_{16} = 1111_2$
• $A_{16} = 1010_2$
• $C_{16} = 1100_2$
• $E_{16} = 1110_2$

Combine the binary numbers:

$1111\ 1010\ 1100\ 1110_2$

So, $FACE_{16} = 1111101011001110_2$.

Step 1: Convert Decimal to Hexadecimal

Divide 2016 by 16 and record the remainders:

• $2016 \div 16 = 126$ remainder $0$
• $126 \div 16 = 7$ remainder $14$ (which is E in hex)
• $7 \div 16 = 0$ remainder $7$

Reading the remainders from bottom to top, we get $7E0_{16}$.

Step 2: Convert Hexadecimal to Binary

Convert each hexadecimal digit to its 4-bit binary equivalent:

• $7_{16} = 0111_2$
• $E_{16} = 1110_2$
• $0_{16} = 0000_2$

Combine the binary numbers:

$0111\ 1110\ 0000_2$

So, $2016_{10} = 7E0_{16} = 1111100000_2$.