Computer Studies (English) - For Class SSC - Part 1 (Science Group) - Solved Model papers 2020 -2021- AS PER CONDENSED SYLLABUS

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Computer Studies (English)
For Class SSC - Part 1 (Science Groups)
Solved Model papers 2020 -2021
As Per condensed Syllabus

SECTION "B"
SHORT ANSWERS QUESTIONS (18 Marks)

Note: Answer any Two (2) questions from this section. All questions carry equal marks.
Q.2: What a hacker can do to your computer?
Ans: Hackers: Hackers are cyber criminals. Hacker can be a person who has in-depth knowledge of computer systems, networks, and programs. Hacker maybe someone who uses his or her extensive skills to identify and overcome a network loophole. Hackers constantly seek further knowledge and freely share what they have discovered.

Q.3: Why do we use "Arrange group" in the Page Layout Tab?
Ans: Arrange Group:
The buttons in Arrange Group help the users to quickly arrange graphical and other elements of the document in relation to the main textual content. These buttons are:

• Position
• Wrap Text
• Bring Forward
• Send Backward
• Selection Pane
• Align
• Group
• Rotate

Q.4: Define any three functions of operating system?
Ans: Functions Of Operating System:
(i) Booting:
Booting is a process of starting the computer operating system.
It checks the computer resources and makes it ready to perform different tasks.

(ii) Resource Management:
Operating system automatically manages all the hardware and software resources of a computer when application programs are executed by computer users.
This includes allocation and de-allocation of processor, memory, access to shared cache memory and access to network resources.

(iii) User Interface or Command Interpreter:
We interact with operating system through user interface or Command Interpreter.
User Interface or command interpreter is one of the parts of operating system which reads the commands from user, interprets them and translates them into machine language instructions that the computer hardware can understand.
(Note: There are given eight functions of operating system in text book Chapter No.2, you can write others of your choice also.)

Q.5: Write three differences between Physical address and Logical address?
Ans: Differences Between Physical Address And Logical address

S.No.	Physical Address	Logical address
1.	Physical address is attached with ROM of the NIC card.	Logical address is assigned to a device.
2.	Physical Addressing means MAC (Media Access Control) provided by manufacture and attached address of the NIC. The card which is used to connect your machine to the internet.	Logical addressing means IP addressing that is provided by your Internet Service Provider (ISP) or set by network administrator.
3.	Physical addressing cannot be can be changed. They are also called hardware address.	Logical Address can be changed.
4.	Physical address is a 48 bit mac address.	Logical address is a 32 bit IP Address.
5.	It is globally Unique and permanent.	It is unique in one network and temporary.

(Note: Do any three if mentioned in question)

Q.6: Define BUS? How many types of buses are there? write their name?
Ans: Buses
In computer, Buses are the electric paths on which data is sent and received by different components. They are just like roads. As roads connect different places, buses connect all the parts of the computer to each other. They also connect all internal components on the motherboard.

Types Of BUS:
There are three types of buses;

1. Control Bus
2. Data Bus
3. Address Bus

Q.7: Define Hypertext Markup Language (HTML)?
Ans: Hypertext Markup Language (HTML):

• HTML stands for Hypertext Markup Language.
• It is standard markup language for text documents.
• HTML is used to create web pages that are displayed by web browsers mainly on internet.
• HTML consists of a series of elements. These elements tell the browser how to display the content.
• It allows the user to create structured content by adding headings, paragraphs, links, blockquotes and other media.
• It takes advantage of simple code structures called tags and attributes to achieve formatting, graphic and navigation effects on web pages.

Q.8: Why is computer security being important? Write any two reasons?
Ans: Importance of Computer Security:
Computer security is important for our computer's overall health, because the computer has become an important part of our life. We store important data on our computers in the shape of documents, pictures, programs, etc. Therefore, we expect that all our information must remain safe and our computer runs properly without any problem.

Reasons Of Importance of Computer Security:

1. Prevent from viruses and malware:
It keeps our information protected and helps prevent viruses and malware, which allows programs to run quicker and smoother.
2. Secure Private Information:
It safeguards confidential and sensitive information. This information may include our passwords, banking details, contacts, pictures, etc. To protect this information we need to make our devices secured that no one can damage or access this information without our consent.
3. Provide Safe Environment:
Computer Security is important as it enables people to perform their work in safe environments.
It helps in the execution of essential business processes.
(Note: write down any two as mentioned in question)

Q.9: Define the following : (any one)

1. Computer Network
2. Data Communication

Ans: 1. Computer Network:
Computer networks are just like a highway on which data can travel. It connects parts of distributed system including hardware and software. It shares common functions and features like data and devices which is very important nowadays.
A computer network is a group of computers and related equipment connected by a communication links to share data and other resources.
The Related Equipment may be printer, scanners, fax machines, server, etc.
The Resources may include a file server, internet connection, etc.

2. Data communication:
Data communications refers to the sharing of a virtual message. Data communication is the exchange of digital messages between two devices. It involves a sender and a receiver which communicate via some form of transmission medium such as a cable.
Example:
Electronic communications, like emails and instant messages and phone calls are examples of data communications.

Q.10: Write any three differences between Analog Signals and Digital signals?
Ans: Difference Between Analog Signals and Digital signals

S.No.	Analog Signals	Digital signals
1.	An analog signal is a continuous wave that changes by time period.	A digital signal is a discrete wave that carries information in binary form.
2.	Analog signal has no fixed range.	Digital signal has a finite number i.e. 0 and 1.
3.	An analog signal can easily be disturbed by other signals or waves.	A digital signal is less prone to other signals disturbance.
4.	The human voice is example of an analog signal.	Signals used by computer are the digital signal.
5.	An analog signal is represented by a sine wave.	A digital signal is represented by square waves.
6.	Analog signals are long term waves need to be boosting.	Digital signals are short term signals remain within digital devices / electronic.

(Note: Do any three as mentioned in question)

SECTION "C"
(DESCRIPTIVE - ANSWER QUESTIONS) (12 Marks)

Note: Answer any Two (2) questions from this section. All questions carry equal marks.

Q.11: Define CPU and Microprocessor and their major parts.
Ans: Microprocessor (CPU):
Definition:
Microprocessor is also called (CPU ) Central Processing Unit. CPU or microprocessor is the brain of computer. The microprocessor or CPU is a chip which is made up of silicon and containing millions of tiny transistors. These transistors manipulate data. The CPU is housed in the computer's mother board.

Microprocessor performs all the calculations necessary to make the computer work. Thee microprocessor fetches, decodes, executes and stores all the instructions given by the user or any other device. The speed of computer mainly depends upon the speed of microprocessor. It interprets the data and instructions. It generates control signals. It also produce the address bit needed by memory.

Components Or Parts Of Microprocessor:or CPU
There are typically five components of a microprocessor.

1. Arithmetic Logic Unit (ALU)
2. Control Unit (CU)
3. Clock
4. Registers
5. Cache

(a) Arithmetic Logic Unit (ALU):

1. ALU performs all the actual calculations like arithmetic operations and logical comparisons.
2. Arithmetic operations include addition, subtraction, multiplication and division while logical comparisons include comparing, selecting and matching of data.

(b) Control Unit (CU):

1. Control Unit is responsible for controlling the transfer of data and instructions among other units of a computer.
2. This unit controls the operations of all parts of the computer but does not carry out any actual data processing operations.
3. CU functions just like a traffic policeman.
4. It manages and coordinates all the units of the computer.

(c) Clock:

1. Clock generates pulses and instructions are executed on the basis of pulses.
2. Clock speed is measure in MHz and GHz.

(d) Registers:

1. It is a temporary storage area that holds the data that is being processed.
2. It is also known as programming model which may be of 8 bits, 16 bits, 32 bits or 64 bits.

(e) Cache:

1. Cache is an intermediate storage area, which is available inside microprocessor.
2. The immediate processed information is stored in cache.
3. The cache inside the microprocessor is called internal cache and outside is called external cache.

Q.12: Define Topology. Explain its type?
Ans: Definition Of Topology:
The physical layout in which computers are connected is called topology. The topology of network describes the way computers are connected. Topology is a major design consideration for computer networking.

Types Of Topology:
(i) Bus Topology:
In Bus Topology computers and other devices are connected with a single cable. The central cable is the backbone of the network and every device communicates with the other device through this bus.
The advantages of Bus Topology are simplicity, low cost and easy expansion of the network. The disadvantage of the Bus Topology is that a breakdown in the bus cable brings the entire network down.

(ii) Ring Topology:
In Ring Topology, computers are connected in a ring or circle shape. The signal travels around the loop in one direction and passes through each computer. The recipient of the message receives the message while another computer acts like a repeater to send it to the next computer.
The failure of a link or a computer can make the entire network nonfunctional.

(iii) Star Topology:
In a star topology, all the computers are connected to a central device called hub or switch. To communicate with any computer, the sender must send information to the hub. Then the hub transmits that information to the destination.
The advantages of star topology are easy to set up and easy expansion of the network. Another feature of Star Topology is that if one link to the hub breaks, only the station using that link is affected not the whole network.

Q.13: Explain the basic components of DBMS?
Ans: BASIC COMPONENTS OF DBMS
The basic components of DBMS are:

• Table
• Field
• Record
• Data Types
• Views

(i) Table:

• It is a collection of data elements organized in shape of rows and columns.
• Example:
  (i) A contact list may be one of the simplest examples of a table.
  (ii) The marks record prepared by a class teacher is also an example of a table.

(ii) Field:

• It is the smallest component in a database.
• It is where the actual data is stored during data entry.
• All data fields in the same table, have unique names.
• Fields are also called attributes or columns.
• Multiple fields make up a data record, several data records make up a data table, and several data tables make up a database.

(iii) Record:

• A single entry in a table is called a record.
• Records are also referred as tuples or rows.
• A record is made up of two or several data items which are also called tuples in a table representing a set of related data.
• For example, the illustrated Student table has 4 tuples /records/rows.

Components Of Tables

(iv) Data Types:

• All fields in a table must have some data type.
• Data type is a data storage format that can contain a specific type or range of values.
• The data type of a field is a property that tells what kind of data that eld can hold.
• Different DBMSs offer different range of data types to be stored.
• Here are some basic data types:

Data Type	Description	Examples
Integer	Holds only whole numbers.	145, -35, 74586
Floating Point	Holds numbers with decimal points.	5.6, 3.14, 554.9
Character	Stores only one character.	A, B, c, d
String	Can store a combination of numbers, letters and special characters.	Pakistan, Computer, @admin
Boolean	Can hold only Boolean values i.e. true or false.	1,0
Date And Time	Stores date and time in specified format.	01-01-2020 11:30

For example:

• MS Access allows a range of whole numbers from -32768 to 32767 for an “Integer”.
• In modern DBMS, choosing proper data type is important to make sure that database runs faster.

(v) Views:

• In a database the data is stored in tables. However, we can see that data through views.
• Views do not store data and just show the information virtually.
• They have the ability to fetch data from different tables.
• Views maintain the security of data and ensure that no changes occur in the original data.

Q.14: What are the properties of a Good Communication System?
Ans: Properties of a Good Communication System:
The effectiveness of a data communications system depends on the fundamental characteristics which include delivery, accuracy and timeliness.

S.No.	Characteristic	Description
1.	Delivery	Making sure that the data is delivered is the first fundamental characteristic of any communication network. The system must be able to deliver data in correct order to the correct destination.
2.	Accuracy	The system must deliver the data accurately. Data that has been altered during transmission and left uncorrected is not useful.
3.	Timeliness	The data must be delivered in a timely manner. Late delivered data is useless.