ANS1. 1.

Input Devices:
The input device is defined as it converts incoming data and
instructions into a pattern of electrical signals in binary code that are
comprehensible to a digital computer. Example:
Keyboard, mouse, scanner, microphone etc.

2. Output Devices:
An output device is generally the reverse of the input process and
generally translates the digitized signals into a form intelligible to the
user. The output device is also performed for sending data from one
computer system to another. For some time punched card and paper
tape readers were extensively used for input, but these have now been
supplanted by more efficient devices.
Example:
Monitors, headphones, printers etc.
. The storage device is one of the most required devices
and also provides better compatibility. Example:
Hard disk, magnetic tape, Flash memory etc.

Hard Drive: A hard drive is a storage device that stores data and files on
a computer system.

USB Drive: A USB drive is a small, portable storage device that connects
to a computer system to provide additional storage space.

Memory Card: A memory card is a small, portable storage device that is

commonly used in digital cameras and smartphones.
External Hard Drive: An external hard drive is a storage device that
connects to a computer system to provide additional storage space.

4. Communication Devices:
Communication devices are used to connect a computer system to
other devices or networks. Examples of communication devices include:

Modem: A modem is a communication device that allows a computer

system to connect to the internet.
Network Card: A network card is a communication device that allows a
computer system to connect to a network.
Router: A router is a communication device that allows multiple devices
to connect to a network
The most commonly used 5 peripheral devices are –
Printer
Scanner
Keyboard
Mouse
Tape device
Microphone

ANS2. A digital computer can be defined as a programmable machine

which reads the binary data passed as instructions, processes this
binary data, and displays a calculated digital output. Therefore, Digital
computers are those that work on the digital data.

Details of Functional Components of a Digital Computer

Input Unit :The input unit consists of input devices that are attached to
the computer. These devices take input and convert it into binary
language that the computer understands. Some of the common input
devices are keyboard, mouse, joystick, scanner etc.
Central Processing Unit (CPU) : Once the information is entered into the
computer by the input device, the processor processes it. The CPU is
called the brain of the computer because it is the control center of the
computer. It first fetches instructions from memory and then interprets
them so as to know what is to be done. If required, data is fetched from
memory or input device. Thereafter CPU executes or performs the
required computation and then either stores the output or displays on
the output device. The CPU has three main components which are
responsible for different functions – Arithmetic Logic Unit (ALU),
Control Unit (CU) and Memory registers
Arithmetic and Logic Unit (ALU) : The ALU, as its name suggests
performs mathematical calculations and takes logical decisions.
Arithmetic calculations include addition, subtraction, multiplication and
division. Logical decisions involve comparison of two data items to see
which one is larger or smaller or equal.
Control Unit : The Control unit coordinates and controls the data flow in
and out of CPU and also controls all the operations of ALU, memory
registers and also input/output units. It is also responsible for carrying
out all the instructions stored in the program. It decodes the fetched
instruction, interprets it and sends control signals to input/output
devices until the required operation is done properly by ALU and
memory.
Memory Registers : A register is a temporary unit of memory in the
CPU. These are used to store the data which is directly used by the
processor. Registers can be of different sizes(16 bit, 32 bit, 64 bit and so
on) and each register inside the CPU has a specific function like storing
data, storing an instruction, storing address of a location in memory
etc. The user registers can be used by an assembly language
programmer for storing operands, intermediate results etc.
Accumulator (ACC) is the main register in the ALU and contains one of
the operands of an operation to be performed in the ALU.
Memory : Memory attached to the CPU is used for storage of data and
instructions and is called internal memory The internal memory is
divided into many storage locations, each of which can store data or
instructions. Each memory location is of the same size and has an
address. With the help of the address, the computer can read any
memory location easily without having to search the entire memory.
when a program is executed, it’s data is copied to the internal memory
and is stored in the memory till the end of the execution. The internal
memory is also called the Primary memory or Main memory. This
memory is also called as RAM, i.e. Random Access Memory. The time of
access of data is independent of its location in memory, therefore this
memory is also called Random Access memory (RAM). Read this
for different types of RAMs
Output Unit : The output unit consists of output devices that are
attached with the computer. It converts the binary data coming from
CPU to human understandable form. The common output devices are
monitor, printer, plotter etc.

The main PARTS of a computer are:

The CPU - This is the brains of the computer. ...
CPU Cooler - This cools the CPU and helps the CPU maintain cool so
that it may perform computations at low temperatures and therefore
more stably.
RAM - Short term memory. ...
Hard Drive - Mass storage with all your things in it.
ANS3. The purpose of a UPS is to provide emergency power (usually by
a lead/acid battery) to a load when it senses that the input power
source has failed. They are different from emergency power systems or
standby generators because they provide near-instantaneous
protection from power interruption by using a battery (which can be a
supercapacitor or flywheel).
The battery itself usually has a short runtime (about 5-20 minutes), but
it should be enough to either save all that precious data/progress that
you have made, gracefully shut everything down, or fix the problem
that caused the outage.
A UPS can be used to protect hardware like data centers, computers,
and other electrical equipment where an unexpected surge/sag can
cause serious problems like data loss, business disruption, and even
injuries or fatalities.
Types of Uninterruptible Power Supplies
There are three types of uninterruptible power supplies: static, dynamic
(rotary), and hybrid. Static uses power electronic converters, dynamic
uses electromagnetic engines (generators and motor), and hybrid uses
– you guessed it – a combination of both static and dynamic. Let’s take
a look at how these topologies are commonly used for electronics.
1. Offline/Standby Uninterruptible Power Supply
The offline/standby UPS is the most basic out of the three. It provides
light surge protection and battery back-up. During normal operations, it
gets its power from its main power source (generally an AC outlet).
Once it senses that the main power source goes beyond acceptable
limits or fails, it switches to the “offline/standby” battery where it will
then go to the DC/AC inverter – as such, there will be a small transfer
time between the main power source and battery.
What’s usually in a standby/offline uninterruptible power supply?
Most standby/offline UPS have a switch to either run on the main
power source or the battery component. The majority of the bulk is in
the battery component, as the main power supply goes to the AC/DC
rectifier that charges the battery. After that it goes into a DC/AC
inverter to output into the load.
 Figure 1: Offline/Standby UPS (green represents the
flow of process).
2. Online/Double Conversion Uninterruptible Power Supply
The online/double conversion UPS differs from the offline/standby as
the DC/AC inverter is always connected on. This means there will be no
transfer time between the main power source and battery, providing
greater protection against spikes, sags, electrical noise, and complete
power failure.
What’s usually in an online/double conversion uninterruptible power
supply?
The main power source in double conversion UPS goes into the AC/DC
rectifier even during normal operations, so it must go through a DC/AC
inverter every time, hence the term “double conversion.”

Figure 2: Online/Double Conversion UPS (green represents

the flow of process).
3. Line-Interactive Uninterruptible Power Supply
The line-interactive UPS has a similar design to the offline/standby, but
with properties of an online/double conversion as well. The line-
interactive design can handle small under-voltages and over-voltages
(about 20% from its standard voltage) by using a multi-tap variable
voltage autotransformer or buck-boost converter. Even during these
small under/over-voltages, the battery is not being used and is still
being charged until there is a big under/over-voltage.
What’s usually in a line interactive uninterruptible power supply?
The design is similar to offline/standby, but it either has an
autotransformer or a buck-boost converter on the main line. This will
either boost the voltage for under-voltages or buck the voltage for
over-voltages.

Figure 3: Line-interactive UPS (green represents the

flow of progress).
Uninterruptible Power Supply Comparison
We created a simple table that breaks down the pros and cons of each
of each type of uninterruptible power supply.

Bottom line:
Offline/standby UPS is the most basic, and they are good for
applications like home computers, printers, or scanners.
Online UPS is the most reliable and offers the best protection, making
them ideal for motor applications or situations where you can’t afford
any transfer time. Best uses are for data centers or intensive care units.
Line-interactive UPS would be suitable for light sag and surges, plus it
has lower electric consumption. If you want a reliable, efficient, and
cost-effective UPS, the line-interactive is the way to go.
ANS4. Types of Expansion Card
Different types of expansion cards are as follows:
1. Video Card
It is also called a video adapter or graphics card. It converts computer
output into a video signal and sends it to the monitor to display. This
card connects the motherboard to the computer monitor. The card
contains Video RAM memory. The amount of memory located on the
card must be enough to support the desired number of colors and
resolutions.
Currently, it has a 32 MB capacity. Some modern video cards also have
their own processors. The video card’s processor receives calls from the
CPU that are intended for graphics processing. It significantly speeds up
graphics processing.
2. Sound Card
Sound cards increase the sound-generating abilities of a computer. It
inputs sound through the microphone and converts it into a form that
can be processed by a computer. It output the sound through speakers.
Network Interface Card (NIC)
A network interface card is also called a network card. It allows the
computer to communicate through the network. The network interface
Card (NIC) is a small electronic device that enables a computer to
communicate over a local area network (LAN). In addition to connecting
two computers together, a NIC provides a connection between a LAN
and a router or switch.
4. TV Tuner Card
A TV tuner card is used to watch television, capture video, and surf the
Internet at the same time. It is also known as television boards and
personal video recorder cards. It contains a TV tuner and video
converter that changes the TV signal in a form that can be displayed on
the monitor.
5. Modem card
A modem card is also called an internal modem. It is a communication
device that enables computers to communicate via telephone lines or
other means.
ANS6. A port is a physical docking point using which an external device
can be connected to the computer. It can also be programmatic docking
point through which information flows from a program to the computer
or over the Internet. Let us now discuss a few important types of ports
−
Serial Port
Used for external modems and older computer mouse
Two versions: 9 pin, 25 pin model
Data travels at 115 kilobits per second
Parallel Port
Used for scanners and printers
Also called printer port
25 pin model
IEEE 1284-compliant Centronics port
PS/2 Port
Used for old computer keyboard and mouse
Also called mouse port
Most of the old computers provide two PS/2 port, each for the mouse
and keyboard
IEEE 1284-compliant Centronics port
Universal Serial Bus (or USB) Port
It can connect all kinds of external USB devices such as external hard
disk, printer, scanner, mouse, keyboard, etc.
It was introduced in 1997.
Most of the computers provide two USB ports as minimum.
Data travels at 12 megabits per seconds.
USB compliant devices can get power from a USB port.
VGA Port
Connects monitor to a computer's video card.
It has 15 holes.
Similar to the serial port connector. However, serial port connector has
pins, VGA port has holes.
Power Connector
Three-pronged plug.
Connects to the computer's power cable that plugs into a power bar or
wall socket.
Firewire Port
Transfers large amount of data at very fast speed.
Connects camcorders and video equipment to the computer.
Data travels at 400 to 800 megabits per seconds.
Invented by Apple.
It has three variants: 4-Pin FireWire 400 connector, 6-Pin FireWire 400
connector, and 9-Pin FireWire 800 connector.
Modem Port
Connects a PC's modem to the telephone network.
Ethernet Port
Connects to a network and high speed Internet.
Connects the network cable to a computer.
This port resides on an Ethernet Card.
Data travels at 10 megabits to 1000 megabits per seconds depending
upon the network bandwidth.
Game Port
Connect a joystick to a PC
Now replaced by USB
Digital Video Interface, DVI port
Connects Flat panel LCD monitor to the computer's high-end video
graphic cards.
Very popular among video card manufacturers.
Sockets
Sockets connect the microphone and speakers to the sound card of the
computer.

ANS7. A hard drive is a non-volatile hardware component on a

computer that acts as the storage for all digital content. It holds
program files, documents, pictures, videos, music, and more.
The non-volatile nature of hard drives means they don’t lose data, even
if power is lost. Due to this, they help computers store files and other
data for a long time – as long as they don’t get damaged or corrupted.
Since the first release of hard drives by IBM in 1956, hard drives have
evolved from being the size of a refrigerator and having a storage
capacity of just 5MB to ones that are pocket-sized and have up to 4 TB
of storage capacity.
Types of Interfaces
Parallel Advanced Technology Attachment (PATA)
Serial Advanced Technology Attachment (SATA)
Small Computer System Interface (SCSI)
NVMe (Non-volatile Memory Express)
These names come from the way they connect to the computer. So,
there are PATA hard drives, SATA hard drives, SCSI hard drives, and
NVMe drives.
In this article, I’m now going to elaborate on each of these interfaces
and types of hard drives as concisely as possible.
Parallel Advanced Technology Attachment (PATA)
The PATA interfaces were first introduced to the market by Compaq
and Western Digital in 1986. They can have up to 80GB capacity and
transfer data as fast as 133 MB/S.
They were named Parallel Advanced Technology Attachment because
they use a parallel ATA interface to connect to the computer. Apart
from PATA, they are also called Integrated Drive Electronics (IDE) and
Enhanced Integrated Drive Electronics (EIDE).
PATA interfaces are made of mechanical moving parts and are based on
parallel signaling technology – meaning they transmit multiple bits of
data simultaneously.
Serial Advanced Technology Attachment (SATA)
In recent times, a lot of desktop and laptop computers have gotten
SATA interfaces because they have superseded PATA interfaces in size,
power consumption, and even better pricing.
The mode of connection to a computer remains the same as PATA, but
instead of parallel signaling technology for data transmission, they use
serial signaling technology. This means that they transfer data one bit
at a time.
A notable advantage SATA interfaces have over PATA interfaces is the
transmission of data at a rate of 150 – 300 MB/S. In addition, they have
thinner cables and a cable limit of 1 meter.
Small Computer System Interface (SCSI)
SCSI interface is an upgrade over SATA and PATA interfaces for many
reasons such as round-the-clock operations, speed, storage, and several
others.
For connection, SCSI hard drives use a small computer system interface
– which is a standard for connecting peripheral devices such as printers,
scanners, and others.
ANS8. RAM(Random Access Memory) is a part of the computer’s Main
Memory which is directly accessible by the CPU. RAM is used to Read
and Write data into it which is accessed by the CPU randomly. RAM is
volatile in nature, which means if the power goes off, the stored
information is lost. RAM is used to store the data that is currently
processed by the CPU. Most of the programs and data that are
modifiable are stored in RAM.
How Do I Know What Type of RAM my Computer Uses?
You can use system information tools or software such as CPU-Z or
HWiNFO to identify the type of RAM installed in your computer. You
can also check the motherboard manual or consult the manufacturer’s
website for information on compatible RAM types.
Integrated RAM chips are available in two forms:
SRAM (Static RAM)
DRAM (Dynamic RAM)
The block diagram of the RAM chip is given below.

RAM Block Diagram

What is SRAM?
The SRAM memories consist of circuits capable of retaining the stored
information as long as the power is applied. That means this type of
memory requires constant power. SRAM memories are used to
build Cache Memory.
SRAM Memory Cell
Static memories(SRAM) are memories that consist of circuits capable of
retaining their state as long as power is on. Thus this type of memory is
called volatile memory. The below figure shows a cell diagram of SRAM.
A latch is formed by two inverters connected as shown in the figure.
Two transistors T1 and T2 are used for connecting the latch with two-
bit lines. The purpose of these transistors is to act as switches that can
be opened or closed under the control of the word line, which is
controlled by the address decoder. When the word line is at 0-level, the
transistors are turned off and the latch remains its information. SRAM
does not require refresh time. For example, the cell is at state 1 if the
logic value at point A is 1 and at point, B is 0. This state is retained as
long as the word line is not activated.

SRAM Memory Cell

For the Read operation, the word line is activated by the address input
to the address decoder. The activated word line closes both the
transistors (switches) T1 and T2. Then the bit values at points A and B
can transmit to their respective bit lines. The sense/write circuit at the
end of the bit lines sends the output to the processor.
For the Write operation, the address provided to the decoder activates
the word line to close both switches. Then the bit value that is to be
written into the cell is provided through the sense/write circuit and the
signals in bit lines are then stored in the cell.
What is DRAM?
DRAM stores the binary information in the form of electric charges
applied to capacitors. The stored information on the capacitors tends to
lose over a period of time and thus the capacitors must be periodically
recharged to retain their usage. DRAM requires refresh time. The main
memory is generally made up of DRAM chips.
DRAM Memory Cell
Though SRAM is very fast, it is expensive because of its every cell
requires several transistors. Relatively less expensive RAM is DRAM,
due to the use of one transistor and one capacitor in each cell, as
shown in the below figure., where C is the capacitor and T is the
transistor. Information is stored in a DRAM cell in the form of a charge
on a capacitor and this charge needs to be periodically recharged.
For storing information in this cell, transistor T is turned on and an
appropriate voltage is applied to the bit line. This causes a known
amount of charge to be stored in the capacitor. After the transistor is
turned off, due to the property of the capacitor, it starts to discharge.
Hence, the information stored in the cell can be read correctly only if it
is read before the charge on the capacitors drops below some
threshold value.

ANS9
1) ATX (Advanced Technology Extended) is a motherboard and power
supply configuration specification, patented by David Dent in 1995
at Intel,[1] to improve on previous de facto standards like the AT
design. It was the first major change in desktop computer
enclosure, motherboard and power supply design in many years,
improving standardization and interchangeability of parts. The
specification defines the dimensions; the mounting points; the I/O
panel; and the power and connector interfaces among a computer
case, a motherboard, and a power supply.
Overview[edit]
ATX is the most common motherboard design.[2] Other standards for
smaller boards (including microATX, FlexATX, nano-ITX, and mini-ITX)
usually keep the basic rear layout but reduce the size of the board and
the number of expansion slots. Dimensions of a full-size ATX board are
12 × 9.6 in (305 × 244 mm), which allows many ATX chassis to
accept microATX boards. The ATX specifications were released by Intel
in 1995 and have been revised numerous times since. The most recent
ATX motherboard specification is version 2.2.[3] The most recent
ATX12V power supply unit specification is ATX 3.0 released in February
2022.
2) A processor is an integrated electronic circuit that performs the
calculations that run a computer. A processor performs arithmetical,
logical, input/output (I/O) and other basic instructions that are passed
from an operating system (OS). Most other processes are dependent on
the operations of a processor.
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The terms processor, central processing unit (CPU) and microprocessor
are commonly linked as synonyms. Most people use the word
“processor” interchangeably with the term “CPU” nowadays, it is
technically not correct since the CPU is just one of the processors inside
a personal computer (PC).
The Graphics Processing Unit (GPU) is another processor, and even
some hard drives are technically capable of performing some
processing.
Techopedia Explains Processor
Processors are found in many modern electronic devices, including PCs,
smartphones, tablets, and other handheld devices. Their purpose is to
receive input in the form of program instructions and execute trillions
of calculations to provide the output that the user will interface with.
A processor includes an arithmetical logic and control unit (CU), which
measures capability in terms of the following:
Ability to process instructions at a given time.
Maximum number of bits/instructions.
Relative clock speed.

3) A power supply unit (PSU) converts mains AC to low-voltage

regulated DC power for the internal components of a computer.
Modern personal computers universally use switched-mode power
supplies. Some power supplies have a manual switch for selecting input
voltage, while others automatically adapt to the main voltage.
Most modern desktop personal computer power supplies conform to
the ATX specification, which includes form factor and voltage
tolerances. While an ATX power supply is connected to the mains
supply, it always provides a 5-volt standby (5VSB) power so that the
standby functions on the computer and certain peripherals are
powered. ATX power supplies are turned on and off by a signal from
the motherboard. They also provide a signal to the motherboard to
indicate when the DC voltages are in spec, so that the computer is able
to safely power up and boot. The most recent ATX PSU standard is
version 3.0 as of mid-2022.

4) Parallel Computing :
It is the use of multiple processing elements simultaneously for solving
any problem. Problems are broken down into instructions and are
solved concurrently as each resource that has been applied to work is
working at the same time.
Advantages of Parallel Computing over Serial Computing are as follows:
It saves time and money as many resources working together will
reduce the time and cut potential costs.
It can be impractical to solve larger problems on Serial Computing.
It can take advantage of non-local resources when the local resources
are finite.
Serial Computing ‘wastes’ the potential computing power, thus Parallel
Computing makes better work of the hardware.

Types of Parallelism:
Bit-level parallelism –
It is the form of parallel computing which is based on the increasing
processor’s size. It reduces the number of instructions that the system
must execute in order to perform a task on large-sized data.
Example: Consider a scenario where an 8-bit processor must compute
the sum of two 16-bit integers. It must first sum up the 8 lower-order
bits, then add the 8 higher-order bits, thus requiring two instructions to
perform the operation. A 16-bit processor can perform the operation
with just one instruction.
Instruction-level parallelism –
A processor can only address less than one instruction for each clock
cycle phase. These instructions can be re-ordered and grouped which
are later on executed concurrently without affecting the result of the
program. This is called instruction-level parallelism.
Task Parallelism –
Task parallelism employs the decomposition of a task into subtasks and
then allocating each of the subtasks for execution. The processors
perform the execution of sub-tasks concurrently.
4. Data-level parallelism (DLP) –
Instructions from a single stream operate concurrently on several data
– Limited by non-regular data manipulation patterns and by memory
bandwidth