PSC Computer Operator Written Exam Question Paper 2079/05/24

PSC
Competitive Written Examination for The Post of Assistant Computer Operator (Technical), Nepal Miscellaneous Service, Gazetted Second Class, 2079-05-24

Time: 2 Hours 15 Minutes
Paper: Second
Full Mark: 100

Subject: Service Related

The answers to the following questions should be written in separate answer sheets according to the section, otherwise the answer sheet will be canceled.

Section-A
1. Differentiate between firmware and cache memory.
Differentiate between firmware and cache memory are as given below.

Parameter	Firmware	Cache Memory
Definition	A piece of programming code embedded in a particular hardware.	High speed memory that increase computer performance.
Nature	Software	Hardware
Residence	Resides in ROM or flash memory.	Resides between main memory and CPU.
Function	Controls hardware device.	Reduces the average time to access data from the main memory.
Installation	Installed in h/w chip and h/w manufacturer.	Intalled by computer manufacturer.
Alternative name	Embedded software or software for hardware.	Buffer memory.
Example	BIOS in ROM of PC.	Different Level: L1 to L6.

2. What do you understand by a software? Explain its types.
Software
Computer needs data and instruction to perform any task. Sequence of data or instruction given to computer to perform certain task is termed as computer program. Computer software can be defined as the set of programs. Software refers to applications, script and program that run on device.

Types of Software
a. Application Software

Application software is the type of computer software that is designed to perform specific task.
User uses application software to solve personal problem in daily life.
Application software is used to perform a specific personal, educational and business function.

Types
i. Packaged software
ii. Tailored software

b. System Software

System software is the type of software that is designed to run on hardware and other application software.
It controls and works with computer hardware.

Types
i. Operating system
ii. Utility software
iii. Device driver
iv. Programming language and language processor

3. Briefly explain the functions of operating system.

Memory management - Directs memory resources to different program.
Process management - Decides which process gets resources when and how long.
Device management - Helps device to communicate with computer.
Job accounting - Keep track of time and resources used by various jobs and user.
Error detection - Traces error and display error message which helps to debug it.
File management - Manages all the file-related activities such as organization storage, retrieval, naming, sharing and protection of files.
Networking - Helps computer to communicate with another computer in network.

4. Explain the process of mail merge with example.
First, we need to create data source with required fields, e.g., Name, address, contact no. etc.
Identify or create main document with required content for letter.
Combine the data source with main document.
Insert required fields from data source to appropriate location in main document.
Complete the merge process after previewing the final output which can be printed as required.

Example
Dear <<FirstName>> <<LastName>>

We would like to thank you for being a loyal customer from <<City>>. We hope to see you at our new store opening soon!

Best regards,
The Company Team

Data source (Excel)

FirstName	LastName	City
Rohit	Chaudhary	Kolhabi

Resulting Merge Letters
Dear Rohit Chaudhary

We would like to thank you for being a loyal customer from Kolhabi. We hope to see you at our new store opening soon!

Best regards,
The Company Team

5. Compare and contrast between Absolute Cell Reference and Relative Cell Reference with suitable example.

Relative Cell Reference	Absolute Cell Reference
It is named after column name and row number.	It is named after column name and row number but with dollar ($) sign.
It doesn't have dollar sign.	It has dollar ($) sign in both row and column.
It takes formula from reference cell automatically change the value according to their relative position.	It will take reference from the only cell that is absolute.
It is default reference.	It can be created by pressing F4 twice times.
It is relative cell reference.	It is fixed cell reference.
A cell can be referred just by specifying the row and column value.	It will only refer to the specific row and column.
When formula is copied it automatically change themselves.	It won't change when the formula is copied to another cell.
Example: A1, A2 etc.	Example: $A$1, $B$2 etc.

6. What do you mean by system tool in operating system? Briefly explain about disk defragmenter and restore tools of Windows OS.
System tool
System tools are built in utilities or programs in an operating system (OS) designed to help monitor, maintain, system restore, task manager, backup and recovery, device manager.

Improves system efficiency
Monitor performance
Performs maintenance

Disk Defragmentation

Disk defragmentation is a system tool that reorganizes fragmented data on hard disk drive (HDD) so that files are stored in contiguous blocks. This reduces the time needed to read/write files. Over time, as you save, delete and modify files, parts of files get scattered across the disk. This slow down performance.

Scans the disk for fragmented files
Re-arrange the file pieces so they stored next to each other
Free up space and improve read/write speeds

Restore tools
System restore is a system tool that allows you to roll back system computer's system files and setting to a previous state without affecting personal files.

The system creates restore points before major changes.
You can revert your system to a selected restore point.

Restore

System files
Installed applications
Windows registry setting

Don't restore

Personal files (e.g. documents, photos)

7. Explain the generation of Computer with key feature of every generation in detail.
Generation of Computer
Based on the development in technology computer can be classified into different time period. This classification is known as the generation of computer. Classification of generation is based on size of computer cost, functionality, storage and memory capacity, speed, power consumption etc.

a. 1st Generation of Computer (1940s - 1950s)

Device/technology used: Vacuum Tube
Language used: Machine language
Memory: Magnetic core memory
Input/output device: Paper tape and punched card
Size: Very large and occupied large space
Speed: Very slow (works in millisecond)

b. 2nd Generation of Computer (1950s - 1960s)

Device/technology used: Transistors
Language used: Machine language and Assembly language
Memory: Magnetic core memory
Size: Smaller than first generation computer
Speed: Faster than first generation computer (works in microsecond)

c. 3rd Generation of Computer (1960s - 1970s)

Device/technology used: Integrated circuit
Language used: High level language
Memory: Magnetic core/magnetic tape
Size: Smaller than second generation computer
Speed: Faster than second generation computer (works in nanosecond)

d. 4th Generation of Computer (1970s - Present)

Device/technology used: Microprocessor
Language used: High level language
Memory: RAM, ROM (Primary), Hard Disk (Secondary)
Speed: Faster than third generation computer (works in picosecond)

e. 5th Generation of Computer (Present - Future)

Will uses ULSI technology and bio chips
Will be based on artificial intelligence
Will function on natural language processing
Will be capable of parallel processing
Faster than other generation (works in femtosecond)
Will recognize voice, image etc.
Will be able to solve problems.

8. Explain the importance of pivot table using example. Write down any five useful functions of MS-Excel.
Pivot table

A static tool of excel that arranges and summarizes complex data in simple tabular form.
A basic data analysis tool that can be used to obtain desired report from large data.

Importance of Pivot table

To get important summary of data from detail data.
To find relationship within the data.
To organize the data into a format that's easy to read.

Useful function of MS-Excel

SUM - To get the sum of cell range. e.g., =SUM (A2, A10).
COUNT - To count the cell with numeric value. e.g., =COUNT (A2, A10).
AVERAGE - To get the mean value of the numbers in a particular cell range. e.g., =AVERAGE (A2, A10).
MAX - To get the largest number in a cell range. e.g., =MAX (A2, A10).
MIN - To get the smallest number in a cell range. e.g., =MIN (A2, A10).

Section-B
9. What is primary and foreign key in database. Clarify it with examples.
Primary Key

A field in a table which uniquely identifies each record in a database table.
A primary key column cannot have null values.
Does not accept duplicate values.
One table can have only one primary key.

Foreign Key

A field in table that refer to the primary key of another table in relationship.
A column or column of child table that connects to the primary key of parent table.
Represent relationship between tables.

Example

Roll No.	Name
1.	Ram
2.	Sita
3.	Gopal

Roll No.	Name
1.	Basic
1.	Advanced
2.	Advanced
2.	Diploma
3.	Basic

10. What is formatting and validating field data in database management system? Give an example to Illustrate.
Formatting field

Formatting means the appearance of data to store in table
It determines the looks of data obtained while accessed by user
Different formatting options are available for different types of data in DBMS (based on MS-Access)

- For Numeric data: General, Currency, Fixed, Standard, Percent etc.

- For Date/Time: Short date, long date, medium date etc.

- For Yes/No: Yes/No, True/False, On/Off

Validating field

Validating field means controlling and limiting the value that can be entered into particular field in table.
Data type that is selected for particular field limit the type of data in some extent.
Data validation specifies the criteria of data to be entered.
It can also provide options and range of valid data.
In access validation can be defined for any type of data of cell.
E.g. validation rule '>15' defines than only numeric data larger than 15 can be entered in particular field.

11. What is presentation system? Explain the usage of presentation system in government office.
Presentation System

Application software that is used to create visual presentation composed of series of slides.
To convey message, present or share data or information related to any topic.
Example: Microsoft PowerPoint, Google slide.

Usage of Presentation system in government office

To provide a framework about product or service of a company.
To build a good reputation of organization.
Conduct training for employee of organization
To build relation among the employee by internal communication.
To share new ideas.
To conduct meeting.
To present periodic and final report.
To present data and analyze it.

12. Define IP address, subnet mask and default gateway.
IP address

Unique id of computer that is connected to network.
Known as logical address of computer.
Provides identity to computer in a network.
Two version of IP address are available: version 4 (IPv4) and version 6 (IPv6)
IP version 4 is made up 32 bits denoted by dotted decimal notation.
Can be classified into 5 different classes.

Subnet mask

32 bit number that break an IP address into network bits and host bits.
Define the range of IP addresses that can be used within a network or subset.
Represented with all 1's in the network portion and with all 0's in the host portion.

Default gateway

A route or path, to which information is passed when the device does not know where the destination is present.
An intermediate device between the local network and the internet.
Transfers internal data to the internet and back again.
Forwards the packet from the client to other network.
Makes it possible for devices in one network to communicate with devices in another network.

13. What is cyber security? What are the various common security threats?
Cyber security
Cyber security is the practice of protecting systems, network devices and data from digital attacks, unauthorized access, damage or theft. It's a broad field that includes technologies processes and practices designed to defend.

Computer threat
Any negative action or event that leads to loss or corruption of data or physical damage to the hardware.

Various common security threat
Computer virus

A computer virus that destroys or damage data, information and program residing in the computer.
E.g. Boot sector virus, scripting virus.

Spyware

A type of malware that gathers data from computer and forward to third party.
E.g. Trojan horse, key logger

Computer worms

A destructive malware program that replicates itself in order to spread to others computer through computer network.

Logic bomb

A piece of code intentionally inserted into a software system that will set of malicious function when specified conditions are met.

Phishing

Bait sent by attacker in the form of an email to encourage people to share their details.

14. Discuss the functions, duties and power of controller as per Electronic Transaction Act.
Function and duties of controller

To issue license to CA
To supervise and monitor the activities of CA
To fix standard to be maintained by CA
To specify procedure to be followed by CA while dealing with subscriber.
To maintain the record of information disclosed by CA
To perform function as prescribed

Function of certifying authorities

To issue a certificate to subscriber
To suspend the certificate
To revoke the certificate

15. What do you understand by Topology? Explain various topologies in detail with a diagram.
Network topology

Network arrangement connecting various node through line of connection
Layout or design of the element of a communication network
Methods in which all the elements of a network are mapped

Various topologies with diagram
Bus topology

All devices share a single communication line
Easy to install, low cost
Difficult to troubleshoot, one cable failure can affect the whole network
Star topology

All devices are connected to a central hub or switch
Easy to manage, failure of one device doesn't affect other
If the hub fails, the entire network goes down
Ring topology

Device are connected in a circular fashion, each device connects to each other
Predictable performance, orderly data flow
Failure of single node, can disturb the whole network
Mesh topology

Every device is connected to every other device
High redundancy, robust and reliable
Expensive and complex to install
Hybrid topology

A mix of two or more topologies
Flexible can be customized to suit needs
Complex and potentially expensive

16. Explain about various security mechanisms in detail.
Computer security
The security technique to keep computer hardware, data and software from unauthorized access, theft, misuse is known as computer security. Various security mechanism used to protect computer system are:

Firewall

Special type of network security device or program which monitor and filter incoming and outgoing data in computer network.
A cyber security tool that filters network traffic and prevents malicious attack.

IDS

Intrusion Detection System is device or software application used for monitoring computer network for malicious activity, security violations and threat.

IPS

Intrusion Prevention System is the process of stopping security threat and incident in computer network detected by IDS.

Email filtering

Used to filter email and separate email into different folders based on specified criteria.
Provides a way to organize email into different categories automatically.
Helps to identify spam, phishing message.

Use of antivirus

Antivirus is used to protect computer from virus and different kinds of malware.
E.g. Norton, Kaspersky etc.

-The End-

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