Data Representation and Transmission Quiz

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Questions and Answers

Which of the following is a reason for using hexadecimal instead of binary?

Hexadecimal is more accurate than binary

Hexadecimal can only represent lowercase letters

Binary uses fewer bits

Hexadecimal is easier to read for humans (correct)

In half-duplex data transmission, data can be transferred in both directions at the same time.

False

What does each character represented by ASCII occupy?

One byte of data

A _______ is the rate at which data transfer occurs, measured in bits per second.

bit rate Signup and view all the answers

Match the data transmission type to its description:

Simplex = One direction only Half-duplex = Both directions but not at the same time Full-duplex = Both directions simultaneously Serial = One bit at a time over a single wire Signup and view all the answers

What is the main disadvantage of parallel data transmission?

Errors are more likely Signup and view all the answers

USB is a synchronous serial data transmission method.

False Signup and view all the answers

What method is used to check if data has changed or corrupted during transmission?

Error-checking methods Signup and view all the answers

What does ARQ stand for in data communication?

Automatic Repeat Request Signup and view all the answers

A firewall is only a hardware-based security measure.

False Signup and view all the answers

What is the main function of anti-virus software?

To detect and remove viruses from the computer. Signup and view all the answers

________ is the act of illegal access to a computer system through a program written to exploit weaknesses.

Hacking Signup and view all the answers

Match the following security terms with their definitions:

Phishing = Fraudulent attempts to acquire sensitive information Cookies = Data used to track user activity on the internet Firewall = Filters incoming and outgoing network traffic Virus = Self-replicating program designed to cause harm to files Signup and view all the answers

Which of the following is NOT a common method of data protection?

Ignoring software updates Signup and view all the answers

Cookies can only be used to store information for one website.

False Signup and view all the answers

What is the primary role of the Control Unit in a processor?

To control the operation of the memory, processor, and input/output devices. Signup and view all the answers

A self-replicating program intended to corrupt files is known as a ______.

virus Signup and view all the answers

What is one effect of phishing?

Access gained to personal details Signup and view all the answers

Study Notes

Data Representation

A byte is a unit of data, normally consisting of 8 bits.
Hexadecimal representation is often used instead of binary because it's easier for humans to read and process, offering a more compact way to represent data and simplifying debugging compared to binary.
ASCII (American Standard Code for Information Interchange) assigns a unique binary code to each character (letters, numbers, punctuation). This allows computers to process and display text.

Data Transmission

Data Transmission Modes:
- Simplex: One-way communication.
- Half-duplex: Two-way communication, but only one direction at a time.
- Full-duplex: Two-way communication simultaneously.
Serial Transmission:
- Data sent one bit at a time over a single wire.
- Suitable for long distances.
- Relatively slow, but cost-effective and less susceptible to errors.
Parallel Transmission:
- Several bits sent simultaneously along multiple wires or channels.
- Rapid transmission over short distances, but less cost-effective and prone to errors over longer distances.
Universal Serial Bus (USB):
- An asynchronous serial data transmission method utilizing a four-wire shielded cable
- Includes wires for power (two) and data transmission (two).
- Computer detects a device upon insertion and loads the associated driver.
- Will prompt the user to download any missing device drivers automatically

Error-Checking Methods

Parity Checking:
- Adds a parity bit to each column of bits (even or odd parity) to detect errors.
- However, it may fail if two bits are altered.
Automatic Repeat Request (ARQ): The receiver sends an acknowledgement to confirm correct data reception, and if not received within a certain time, the sender resends the message.
Checksum: A numeric count of the bits sent is transmitted with the data, allowing verification of complete and accurate transmission.

Security and Ethics

Security Risks:
- Hacking: Unauthorized access to computer systems.
- Effects: Identity theft, data loss/corruption, system disruption.
- Prevention Strategies: Firewalls, robust passwords, anti-hacking software.
- Viruses: Self-replicating programs that corrupt files or cause malfunctions.
- Effects: System crashes, data damage.
- Prevention: Antivirus software, cautious file downloads.
- Phishing: Fake emails tricking users into revealing personal information.
- Prevention: Caution against suspicious emails.
- Cookies: Tracking user activity which may include storing sensitive data, and eventually sell user data to marketing companies.
- Prevention: Caution is needed when using websites that use cookies.

Data Loss Prevention

Data backups: Regular backups are crucial to preventing data loss.
Redundant systems: Having backup hardware in place to ensure continuity of operation

Firewalls

Firewalls: Software or hardware to filter network traffic between your computer and the internet.
Functions:
- Monitor traffic.
- Filters incoming and outgoing data based on defined criteria.
- Prevents access to undesirable websites/content, and warns of unauthorized access attempts

Computer Architecture

Processor: Contains the Arithmetic Logic Unit (ALU) for arithmetic and logic operations.
Control Unit: Manages memory, processor, and input/output devices.
Fetch-Execute Cycle:
- The processor fetches, decodes, and executes instructions sequentially.
- The PC holds the location of the instruction to be fetched.
- The MAR receives the address, which is then read by the MDR.
- The instruction is placed in the CIR, decoded, and executed.

Input Devices

Scanners (barcode, QR codes), digital cameras, keyboards, microphones, sensors, touchscreens.

Output Devices

Monitors, printers, speakers, projectors, headphones.
Touchscreens (Capacitive/Resistive): Different technologies with varying cost, sunlight visibility, multi-touch capability, and durability.

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Description

Test your knowledge on data representation concepts including bytes, hexadecimal representation, and ASCII. Additionally, evaluate your understanding of data transmission modes such as simplex, half-duplex, and full-duplex, along with serial and parallel transmission methods.