INTERNAL ASSIGNMENT - SOLUTIONS
SET-I
Q. No 1: Define the key characteristics of computer that define their functionality and utility.
(10)
Ans: All types of computers have these key characteristics:
1. Speed: Computers are high-speed electronic devices. Operations inside the computer
are performed by electronic circuits. A computer can perform millions of operations
per second. The speed of a computer is measured in Mega Hertz (MHz) or Giga Hertz
(GHz), representing millions or billions of cycles per second.
2. Arithmetical and logical operations: Computers can perform arithmetic and logical
operations. Arithmetic operations include addition, subtraction, multiplication, and
division on numeric data. Logical operations involve comparing numerical and
alphabetical data.
3. Accuracy: A computer provides accurate output if the input data and instructions are
correct. This concept is known as "Garbage-in, garbage-out." Incorrect input and
instructions will result in incorrect output.
4. Reliability: Computers have a very low failure rate and provide consistent results. Most
computers never require a service call in their lifetime, making them highly reliable.
5. Storage: Computers have both internal (memory) and external (secondary) storage.
They can store large amounts of data and programs in secondary storage for future use.
6. Retrieving data and programs: Programs and data from secondary storage can be
loaded into internal storage (memory) for quick access by the CPU during execution.
7. Automation: Computers can automatically perform operations based on the
instructions given in the program without requiring user interference. They can also
control many types of attached devices.
8. Versatility: Modern computers are very flexible. They can perform different tasks
simultaneously, such as playing a game while listening to music or browsing the web.
The tasks you can perform depend on the software.
9. Communications: Computers can exchange messages between different computers
over networks like the Internet. Exchanging messages over networks is a crucial part of
information technology.
10. Diligence: Computers are very diligent and can continue to work on the same task for
hours without any errors, degradation in performance, or fatigue.
11. Feelings: Computers do not have feelings. They rely entirely on the instructions and
data provided to them to make decisions and judgments.
12. Consistency: People usually have difficulty repeating their actions consistently.
Computers, however, can repeat actions consistently without losing concentration. For
example, you can listen to the same song or watch the same lecture repeatedly without
issues on a computer.
13. Precision: Computers are precise machines and can perform operations accurately.
Desired accuracy can be achieved with computers, unlike manual calculations where
fractional values might need to be rounded.
Q. No 2: What is RAM and define its types.
(4+6)
Ans: RAM stands for Random Access Memory.
Random Access Memory provides temporary read-write storage for data and instructions,
unlike hard disks, which provide semi-permanent storage.
The term "random" describes the fact that the CPU can access any individual location or
address within the RAM to fetch data or instructions.
RAM is a volatile memory, which means it needs a continuous flow of electricity to maintain
the data on it. Once the electricity is turned off, the data on the RAM is lost.
Random Access Memory is directly connected to the processor via the memory bus. RAM
has much faster access times compared to other kinds of storage devices.
RAM devices can be divided into two categories:
1. Dynamic Random Access Memory (DRAM)
2. Static Random Access Memory (SRAM)
1. Dynamic Random Access Memory (DRAM):
The memory cell used in DRAM consists of a capacitor. A capacitor can have two states:
fully charged or fully discharged, corresponding to storing one bit of information, either a 1
or 0.
Major advantages of DRAM technology:
•
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It is inexpensive.
The area required to fabricate a cell is very small. Thus, a huge number of cells can fit
into a very small area.
Major disadvantages of DRAM technology:
•
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The data stored in the cell will be lost if it is not refreshed. This is because capacitors
gradually discharge and hence need to be periodically charged. That is, the memory
needs to be refreshed.
The process of reading data from the DRAM cell is destructive in nature. After
reading the data from the cell, the capacitor gets discharged.
Used in: Primary memory chips like SO DIMM, Micro DIMM, EDO RAM, SDRAM, DDRSDRAM, DDR2-SDRAM, DDR3-SDRAM, DDR4-SDRAM, etc.
2. Static Random Access Memory (SRAM):
The memory cell used in SRAM consists of a flip-flop latch. Each flip-flop latch is made up
of four semiconductors and can store one bit of information, either a 0 or 1.
Major advantages of a flip-flop compared to a capacitor:
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It takes less time to store a bit in it compared to capacitor memory cells.
Data stored in this cell is not lost over time. There is no need to refresh the memory.
Reading the data from a flip-flop is non-destructive. When the data is read from a flipflop, the data is not erased.
Major disadvantages of a flip-flop compared to a capacitor:
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Flip-flops are more expensive.
Flip-flops occupy more space as they use four semiconductor switches.
There needs to be continuous power. If the power is lost, the data is lost. Thus, they
are volatile.
Used in: SRAM is used in caches (L1, L2, L3) and registers within the CPU
Q. No 3: Describe the Computer Software and define the use of Operating Systems
(5+5)
Ans:
a. Computer Software
Computer software is an organized collection of data and instructions, divided into two major
categories: System Software and Application Software. System Software performs basic,
non-task-specific functions of the computer, while Application Software performs userspecific tasks.
A computer program reads instructions and data from memory or storage, follows these
instructions step by step, and generates output. The output can vary with each execution,
depending on the data and instructions provided.
Different types of computer software perform various tasks. There are three major types of
computer software:
1. System Software
2. Programming Software
3. Application Software
1. System Software
System Software runs the computer hardware and includes the operating system and device
drivers. It handles system files and provides a library of functions that offer system services.
These include configuration files, assemblers, file management tools, system utilities,
debuggers, and other low-level software. Some operating systems also provide a user
interface.
2. Programming Software
Programming Software includes tools for programmers to write computer programs in
different languages. These tools include compilers, assemblers, and integrated development
environments (IDEs). Compilers convert high-level languages to assembly or machine
language, while assemblers convert assembly language to machine language. Examples of
programming languages are Pascal, Basic, Java, C, and Prolog.
3. Application Software
Application Software performs specific tasks needed by users, such as industrial automation,
business software, educational software, medical software, databases, and computer games.
Application software must be installed on the operating system to be used.
b. Uses of Operating Systems
Operating systems (OS) are essential for computer functionality, acting as an interface
between users, applications, and hardware. Here are the key uses of operating systems:
1. Resource Management:
o CPU Management: Allocates CPU time to processes for efficient multitasking.
o Memory Management: Allocates and manages main memory for processes.
o Storage Management: Manages secondary storage, organizing data and
maintaining file systems.
o Device Management: Controls peripheral devices using drivers for seamless
hardware-software communication.
2. Data Management:
o File System Management: Provides structured storage and retrieval of data on
disk drives.
o
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Data Security: Implements measures to protect data from unauthorized access
and corruption.
Backup and Recovery: Facilitates data backup and recovery to prevent data loss.
3. Job Management:
o Job Scheduling: Controls the order and timing of application execution.
o Batch Processing: Automates repetitive tasks through scheduling and execution
of batch files.
o Priority Management: Manages job priorities to ensure critical tasks receive
necessary resources.
4. Task Management:
o Multitasking: Enables simultaneous execution of multiple programs.
o Process Management: Creates, schedules, and terminates processes.
o Concurrency Control: Manages concurrent process execution to ensure data
integrity and system stability.
5. Device Management:
o Peripheral Control: Manages communication with peripheral devices using
drivers.
o Plug and Play: Automatically detects and configures new hardware devices.
o Resource Allocation: Monitors resources for peripheral devices to optimize
performance and avoid conflicts.
6. User Interface:
o Command Line Interface (CLI): Provides a text-based interface for user
commands.
o Graphical User Interface (GUI): Offers a visual interface with windows, icons,
and menus.
o User Experience: Enhances navigation, online help, and application integration
for better user experience.
SET-II
Q. No 4: Describe the functions of the central processing unit (CPU) and its significant
subunits.
(5+5)
Ans:
Central Processing Unit (CPU)
The central processing unit (CPU) is the electronic brain of the computer. Most personal
computers have a CPU, usually a single chip, that takes in data and instructions from either
the user or the software, executes them, and provides output.
The CPU is made up of many components, but two important ones are the arithmetic and
logic unit (ALU), which handles mathematical calculations and logical comparisons, and the
control unit, which controls the electronic flow of information in the computer.
The CPU is plugged into the motherboard, a rigid rectangular printed circuit board containing
the circuitry that connects the processor and all other components. Some components are
attached directly to the motherboard, while others are plugged into the expansion slots on the
motherboard.
The processing capacity of a computer is measured by the amount of data processed by the
CPU in one operation.
The CPU has three important subunits:
1. Arithmetic Logic Unit (ALU)
2. Control Unit
3. Memory Unit
Arithmetic Logic Unit (ALU):
The ALU performs arithmetic and logical operations. Arithmetic operations include addition,
subtraction, multiplication, and division on numeric data. Logical operations involve
comparing numerical and alphabetical data, such as greater than, less than, equal to, etc.
Comparison operations allow programs to make decisions based on input data and
instructions, while logical operations determine whether a statement is TRUE or FALSE.
Control Unit:
The control unit coordinates the activities of all other units in the system. Its main functions
are to control the transfer of data and information between various units and to initiate
appropriate actions by the ALU. The control unit fetches instructions from memory, decodes
them, and directs them to different units for appropriate tasks.
Memory Unit:
The main memory, also called primary memory, provides temporary read/write access to data
and instructions. When a user needs to execute a program, the CPU requires data and
instructions, which the main memory retrieves from secondary storage and makes accessible
to the CPU. Once the CPU finishes execution, the result is stored back in the main memory,
and from there, it can be transferred to secondary storage.
There are different kinds of primary memory, such as random access memory (RAM) and
read-only memory (ROM). Data can be written and read from RAM, which is volatile
memory, meaning its contents are lost when the power is turned off. On the other hand, data
cannot be written into ROM as it is pre-written by the manufacturer. Other types of RAM
exist, which users can rewrite after erasing either electrically or using UV rays.
Q. No 5: Describe in brief the computers classification.
(10)
Ans:
CLASSIFICATION
OF COMPUTERS
Microcomputer
Mainframe
Computer
Minicomputer
Further
Categories
PC
Desktop PC
Laptop
Computers
Workstations
Supercomputer
Dumb Terminals
Network
Computers
Handheld
Computers
Intelligent
Terminals
Personal Digital
Assistants (PDA)
Tower PC
Cellular Phones
(Smartphones)
H/PC Pro Devices
Classification of Computers
Computers are classified based on data processing speed, data capacity, memory size, and
price. They are generally grouped into four main categories:
1.
2.
3.
4.
Supercomputer
Mainframe Computer
Minicomputer
Microcomputer
1. Supercomputer
Supercomputers are the most powerful and fastest computers, and they are also very
expensive. First developed in the 1980s, they are used to process large amounts of data and
solve complicated scientific problems. They can perform more than 1 trillion calculations per
second and have a large number of processors connected in parallel. A single supercomputer
can handle thousands of users simultaneously.
Uses:
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Weather forecasting
Nuclear energy research
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Aircraft design
Automotive design
Online banking
Industrial control
Examples:
• Cray 1
• Cray 2
• Control Data Cyber 205
• ETA A-10
2. Mainframe Computers
Mainframe computers are large-scale computers, though smaller than supercomputers, and
are also very expensive. They usually require a large, clean room with air conditioning. They
support a large number of equipment and multiple processors, handling thousands of users
simultaneously.
Types of Terminals:
1. Dumb Terminal: No CPU or storage; uses the CPU and storage of the mainframe
system. Consists of a monitor, keyboard, and mouse.
2. Intelligent Terminal: Has its own processor and can perform limited processing;
may or may not have storage. Personal computers can serve as intelligent
terminals.
Uses:
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Servers (World Wide Web)
Banks
Airlines
Universities
Examples:
• IBM S/390
• Control Data Cyber 176
• Amdahl 580
3. Minicomputers
Minicomputers are smaller in size and have lower processing speed and cost than mainframe
computers. Known as midrange computers, they have capabilities between mainframe and
personal computers. Most minicomputers are designed for multiple users through terminals.
Uses:
•
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Businesses
Education
Government departments
Examples:
• IBM AS 400
• Digital Equipment Corporation (DEC)
• Data General Corporation
4. Microcomputers
Microcomputers, also known as personal computers (PCs), use smaller microprocessors and
are small in size and affordable. The first microcomputer, designed by IBM in 1981, was
called the IBM PC.
Types of Personal Computers:
1. Desktop PC: The system unit usually lies flat on the desk, with the monitor
placed on the system unit.
2. Tower PC: The system unit is placed vertically on the desk or floor.
Further Categories:
1. Laptop Computers: Small notebook computers that can fit in a briefcase and
have a special battery for use during travel. Their memory and storage are usually
similar to desktop computers.
2. Workstation: Special single-user computers with processing speeds equivalent to
minicomputers or mainframes. Used by scientists, engineers, architects, and
graphic designers. Workstations are expensive and powerful, using advanced
processors, RAM, and more storage capacity. They can be used for single-user
applications or as servers.
3. Network Computer: Personal computers designed as terminals for network
environments. Usually lack storage and are used for data entry or accessing data
on the network.
4. Handheld Computer: Small personal computing devices, also referred to as
palmtop computers or mini notebook computers. They usually fit in one hand.
Examples:
• Personal Digital Assistants (PDAs)
• Cellular telephones
• H/PC Pro devices
Q. No 6: Describe the various phases of software testing.
(10)
Ans:
Software testing is a systematic process intended to identify errors in a program or system.
This process involves executing the software with the intention of finding and fixing bugs.
The testing starts rom the most detailed level (unit testing) and progresses outwards to the
broader level (integration, validation and system testing). This spiral approach ensures that
testing starts at the smallest component level and expands to include larger and more complex
components which helps in minimizing errors and enhancing software quality.
The various phases of software testing, as illustrated in the spiral model, are as follows:
1. Unit Testing
• Description: This is the first phase of testing, focusing on individual components
or units of the software.
• Objective: Ensure that each unit functions correctly in isolation.
• Techniques: Primarily white-box testing techniques, which involve testing
specific paths in a module's control structure to ensure complete coverage and
error detection.
• Focus: Code functionality at the micro level, targeting individual functions or
methods within the code.
2. Integration Testing
• Description: After unit testing, individual components are combined and tested as
a group to identify issues related to their interactions.
• Objective: Verify that integrated components work together as intended.
• Techniques: Mostly black-box testing techniques, with some white-box testing to
ensure coverage of major control paths.
• Focus: Design and construction of software architecture, ensuring that different
modules or services within the application interact correctly.
3. Validation Testing
•
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Description: This phase validates that the software meets all requirements
specified during the requirements analysis phase.
Objective: Confirm that the software functions as expected under various
conditions.
Techniques: Exclusively black-box testing techniques, which focus on the
outputs generated in response to selected inputs and execution conditions.
Focus: Requirements validation, ensuring that the software satisfies all functional,
behavioral, and performance requirements outlined in the specifications.
4. System Testing
• Description: The final phase of testing where the complete, integrated system is
tested as a whole.
• Objective: Ensure that the entire system works as intended and integrates
seamlessly with other system elements.
• Techniques: Combination of different testing methods, but predominantly blackbox testing.
• Focus: Testing the entire system in an environment that simulates real-world use,
verifying that all components and external interfaces function correctly.
Objectives and Benefits of Software Testing
Testing Objectives:
1. Error Detection: Execute the program with the intent of finding errors.
2. Effective Test Cases: Design test cases with a high probability of uncovering
undiscovered errors.
3. Successful Tests: A test is considered successful if it reveals an undiscovered error.
Benefits of Testing:
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Error Identification: Identifies and helps fix errors in the software.
Function Verification: Demonstrates that software functions according to
specifications.
Reliability Assessment: Provides data on software reliability and quality.
Performance Assurance: Ensures that performance requirements are met.