Computer Basics – Solved Question Paper of MPA 2017 (Spring) – Purbanchal University (PU)

Disclaimer:  The answers are composed by Suresh Khanal and not necessarily score full marks for each question. 

Your suggestions to make the answers complete is appreciated. You can write your answers in comment box below.

​Group A:

Answer TWO questions. (2 x 7 = 14)

1. Why primary ​memory is needed in a computer system? Differentiate between SRAM and DRAM.
   
   Answer: There are two specific storage requirement in a computer system - (1) storing the instructions, data and intermediate results to make processing possible and (2) storing the user data for future reference. For user files and long term storage, we have secondary storage but for the system to be able to process data, we need primary memory. RAM and ROM are the two kinds of primary memory. ROM stores instructions and system configuration  data while RAM loads the instructions, data to be processed and the results. For any application to run, it should be loaded to RAM and resides there until the application is closed.
   
   SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory) are the two types of RAM. Differences are as follows:
   
   1. SRAM can store data as long as power supply is provided while data in DRAM is erased automatically after some time regardless to the power supply.
   
   2. SRAM does not need to be refreshed but DRAM should be refreshed
   
   3. SRAM is more expensive compared to the DRAM
2. Define an operating system. List different functions of an OS and explain any three of them.
   
   Answer: An operating system is a collection of system programs that manages all the other programs (i.e, application programs) in a computer as well as the allocation and use of hardware resources such as the CPU (central processing unit), memory and the hard disk drive (HDD). It controls and facilitates the overall operation of a computer. It acts as an interface between the hardware and the user level program.
   
   Following are the functions of an operating system:
   
   
   • Process Management
   • Memory Management
   • Disk Management
   • Device Management
   • User Interface
   • Data and User security
   • Managing input / output
   • Handling Network communication

   Process Management - Process Management is one of the important function of operating system. An OS must allocate resources to processes, enable processes to share and exchange information, protect the resources of each process from other processes and enable synchronization among processes.

   ​Memory Management - Memory management is another major functionality of an operating system which handles or manages primary memory and moves processes back and forth between main memory and disk during execution. Memory management keeps track of each and every memory location, regardless of either it is allocated to some process or it is free.

   ​Device Management - An Operating System manages device communication via their respective drivers. It keeps tracks of all devices. Program responsible for this task is known as the I/O controller. Decides which process gets the device when and for how much time. Allocates the device in the efficient way. De-allocates devices.

3. What do you mean by computer generation? Explain different types of computer generations.
   
   Answer:

   An international conference in 1962 classified computers into 5 distinct generations – 3 of which are already passed by and we are in fourth generation now. The fifth generation computers are undergoing research and a few computers of this generation are developed that meets some of the expected feature of fifth generation.

   Each generation of computers is characterized by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful, and more efficient and reliable devices.

   First Generation - First generation computers were gigantic in size, used vacuum tubes as their main switching device and magnetic drum for memory. Vacuum tubes consumed  a lot of electricity and produced much heat requiring cooling facilities for room. The operation was expensive as these tubes burnt off frequently.

   Second Generation - By 1948, the invention of the transistor greatly changed the computer’s development. Coupled with early advances in magnetic-core memory, transistors led to second generation computers that were smaller, faster, more reliable and more energy-efficient than their predecessors.

   Third Generation - The computers using IC Chips - small scale integration circuits (SSI)and medium scale integration circuits (MSI) are under this class. The invention of IC Chips made it possible to greatly reduce the size of computers with improvement in operation speed (nanoseconds) and reliability. The most noticeable achievement of third generation is the development of operatingsystems. The operating systems allowed the machines to run many different applications.

   Fourth Generation - Fourth generation for the computers is the era of blooming in multiple dimensions rather than invention of electronic components. Fourth generation computers use ICs as in third generation, but this time Large Scale ICs (LSI), and Very Large Scale ICs (VLSI) are used. As millions of electronic components got integrated in a tiny chip, the computers became very small with increased speed, reliability and reduction in cost. The size of computer reduced to mini computers and microcomputers. Today, we have laptops, palm tops and pocket PCs. Probably the most important development in this generation is microprocessor.

   Fifth Generation - Fifth generation computers are future computers. In 1982 Japan started a project named Fifth Generation Computer Systems Project (FGCS) initiated to create a “fifth generation computer” which was supposed to perform much calculation using massive parallel processing. Fifth generation computers are anticipated new type of computer based on emerging microelectronic technologies with high computing speeds and parallel processing. Other major expectations out of this generation are the ability to use natural language and acquire artificial intelligence (AI). Computers will be able to learn by its experience. These computers are being made using ULSI (Ultra Large Scale IC) and Bio-Chips.​

​Group B:

Answer FOUR questions.  (4 x 4 = 16)

1. ​Higher the size of the register (word-length), faster the computer's processing speed. How?
   
   Answer - Word length is the number of bits that a processor can process at a time. If a system has higher size register or larger word length, it can process more data at a time reducing the time required to complete a task. Thus it increases the processing speed.
2. Define database and DBMS. List characteristics of DBMS.
   
   Answer: A database is the organized collection of data making it easier to retrieve quickly. Telephone directory, Student information register, Dispatch record, Subscriber information record, transaction details etc. are some real life examples of database. A computer system developed to manage these databases electronically is known as Database Management Systems (DBMS). MS Access, Oracle, mySQL etc are some examples of popular DBMS.
   
   Following are the characteristics of DBMS:
   

   Stores any kind of data

   Support ACID (Accuracy, Completeness, Isolation, and Durability) Properties

   Represents complex relationship between data

   Backup and recovery

   Self-Describing Nature of a Database System

   Data integrity

   Concurrent use of database

   Insulation between Program and Data

   Support multiple views of data

   Sharing of data and Multiuser system

   Control Data Redundancy

   Data Sharing

   Enforcing Integrity Constraints

   Restricting Unauthorised Access

   Data Independence

   Transaction Processing

   Providing multiple views of data

   Providing backup and recovery facilities

3. Differentiate between LAN and WAN
   
   Answer: LAN and WAN are the two major types of computer networking. Following are the differences between LAN and WAN
   
   1. LAN is confined within local area ( a room,  a building or a campus) whereas WAN spreads to cover the whole city, country or the world and beyond.
   
   2. It is possible to use Bound transmission media to form a LAN but for WAN unbound media are better preferred.
   
   3. Bus, Ring, Star are some of the popular topologies used in LAN while the network topoogy in WAN are heterogeneous by nature.
   
   4. Network speed much higher and reliable in LAN but for WAN network speed is slower and you must apply mechanism to gain data reliability.
   
   5. It is simpler and easier to form a LAN but establishing WAN is more complex and expensive.
4. Explain star topology with its advantages and disadvantages.
   
   Answer:  Star topology is one of the most popular LAN topology. In star topology there is a central node (computer or network device) that is connected to all other nodes. All the network communication is done through that central node.
   

   Advantages of a Star Topology

   • Easy to install and wire.
   • No disruptions to the network when connecting or removing devices.
   • Easy to detect faults and to remove parts.

   Disadvantages of a Star Topology

   • Requires more cable length than a linear topology.
   • If the hub, switch, or concentrator fails, nodes attached are disabled.
   • More expensive than linear bus topologies because of the cost of the hubs, etc.
5. List different secondary storage devices.
6. Differentiate between system software and application software.