Computer Science Fundamentals – Practice Flashcards

A comprehensive set of flashcards covering number systems, data representation, operating systems, networking, security, algorithms, software engineering, and basic hardware concepts, derived from the provided lecture notes.

What is the base (radix) of the binary number system?

2

What is the base of the octal number system?

8

What is the base of the hexadecimal number system?

16

How many bits make up one byte?

8 bits

What is the maximum value of an unsigned K-digit number in base b?

b^K – 1

What is the maximum value of a 5-bit binary integer?

31

How many distinct bit patterns can a 7-bit code provide?

128 patterns (2^7)

How many address bits are required for a 16 MB (16×2^20 bytes) memory?

24 bits

How many hexadecimal digits are needed to write decimal 20?

2 digits

In binary–to–octal conversion, how many binary bits correspond to one octal digit?

3 bits

Convert binary 1010 1010 0001 0111₂ to hexadecimal.

AA17₁₆

Which hexadecimal digit is equivalent to decimal 12?

C

Give the binary equivalent of the octal number 13.54₈.

1011.1011₂

What is the 8-bit two’s-complement representation of –25?

1110 0111

With 17 exponent bits in an Excess (bias) system, what is the bias value?

65 535 (2^(17-1) – 1)

Approximately how many audio samples per second are needed to reproduce human hearing?

40 000 samples/s

If B is bit depth and S is samples per second, what is the bit-rate formula?

R = B × S

What is the 8-bit ASCII code for the character ‘J’?

0100 1010

What is the result of an arithmetic right shift (1 bit) on 1001 1000₂?

1100 1100

What is the result of a logical (simple) right shift (1 bit) on 1001 1000₂?

0100 1100

What is the result of a logical (simple) left shift (1 bit) on 1001 1000₂?

0011 0000

How many bits are contained in an IPv4 address?

32 bits

In sign-and-magnitude with 4 bits, what happens if –6 − 7 is attempted?

Overflow; closest representable value is –7

Define a process in operating-system terminology.

A program in execution

Which scheduler converts a job into a process and vice-versa?

The Job (or Long-term) scheduler

Which process state is entered while waiting for an I/O operation to finish?

Waiting (or Blocked) state

In mono-programming, how many programs can reside in memory at once?

Only one

Which directory is the highest level in a file-system hierarchy and has no parent?

The root directory

What OS file-system object performs the same organizing role as a folder in a filing cabinet?

A directory

What database design process reorganizes relations to reduce anomalies?

Normalization

What is starvation in operating-system scheduling?

A process waiting indefinitely due to resource restrictions

Give a concise definition of an algorithm.

An ordered set of unambiguous, finite steps that produce a result

What is pseudocode?

An English-like, informal representation of an algorithm

What does UML stand for?

Unified Modeling Language

What does high module coupling indicate?

Modules are strongly inter-dependent (undesirable)

What is modularization?

Breaking a large project into smaller, manageable parts

Define a DoS attack.

An attack that exhausts system resources to reduce or stop service

What is a computer worm?

A self-replicating program that spreads through networks exploiting weaknesses

What is a Trojan horse?

Malicious code hidden inside a benign host program

What is a black-hat hacker?

An attacker with malicious motives such as theft or reputation gain

Who are white-hat hackers?

Security specialists who find and fix vulnerabilities ethically

Which attack threatens confidentiality by interception?

Snooping

Which attack threatens integrity by pretending to be another entity?

Masquerading

Define encryption.

Transforming plaintext into ciphertext to prevent unauthorized reading

Define steganography.

Concealing a message by hiding it within another medium

Which cryptosystem does RSA belong to?

Asymmetric (public-key) cryptography

In RSA, whose public key encrypts a message destined for user B?

User B’s public key

Public-key ciphers are also called what kind of ciphers?

Asymmetric-key ciphers

Which cipher rearranges symbol positions without substitution?

A transposition cipher

Decrypting ciphertext to recover plaintext is called what?

Decryption

Name the three transport-layer protocols in TCP/IP.

TCP, UDP, and SCTP

Which protocol retrieves web pages in the client-server model?

HTTP

Which TCP/IP protocol is standard for file transfer between hosts?

FTP

What primary service does the transport layer provide?

End-to-end delivery of the entire message

How many layers are in the TCP/IP model?

Five

Define a LAN.

A privately owned network limited to a small geographic area

How many discrete levels can an ideal digital signal take?

A limited number (often just two: 0 and 1)

What is sampling in audio digitization?

Measuring the analog signal at discrete time intervals

In bitmap graphics, what is a pixel?

The smallest picture element (sample) of an image

What monitor specification measures sharpness by spacing of mask holes?

Dot pitch

Which printer combines a laser beam with electrophotographic techniques?

Laser printer

What electronic device stores exactly one bit temporarily?

A latch

What is a CPU register?

A stand-alone storage location that holds data temporarily

Which memory type (SRAM/DRAM) must be refreshed periodically?

DRAM

Firmware that starts a PC and loads the OS is called what in IBM PCs?

ROM BIOS

Name the 17-century mechanical calculator for addition and subtraction.

The Pascaline

RISC architectures focus on a small set of what kind of operations?

Simple operations

State the 80–20 cache rule.

80 % of execution time is spent on 20 % of the data

In relational databases, what is a tuple?

A row (record) in a relation

In relational databases, what is an attribute?

A column (field) in a relation

Which hashing term refers to the original address produced?

Home address

Which hashing method guarantees no collisions?

Direct (or perfect) hashing

What is collision resolution by open addressing?

Searching subsequent addresses for an empty slot

What cache concept states CPUs check cache before main memory?

Temporal locality principle (implicit in 80–20 rule)

What is the group of nine tracks on magnetic tape used for?

8 data bits plus 1 parity bit for error detection

Define a data structure.

An organized way to store and access data, e.g., array, record, linked list

Which sorting algorithm repeatedly selects the smallest remaining element and swaps it to the front?

Selection sort

Which sorting algorithm repeatedly bubbles the largest element to the end by swapping adjacent items?

Bubble sort

Which sorting algorithm builds the sorted list by inserting the first item of the unsorted part each time?

Insertion sort

Which search algorithm scans an unordered list element-by-element?

Sequential (linear) search

Which search algorithm halves the search interval in an ordered list?

Binary search

What is recursion?

A process where a function or algorithm calls itself

A stack follows which access discipline?

LIFO (Last-In, First-Out)

A queue follows which access discipline?

FIFO (First-In, First-Out)

In a binary search tree, every left-subtree key is _ the root key.

Less than

Breadth-first traversal of a tree visits nodes in what order?

Level by level, children before the next generation

What does the push operation do on a stack?

Inserts an item at the top

What does the pop operation do on a stack?

Deletes the top item

What two components constitute an Abstract Data Type (ADT)?

A data structure and the operations defined on it

Row-major storage stores two-dimensional arrays how?

Row by row in contiguous memory

What is transferability in software quality?

Ability to move data or software to other platforms and reuse code

What is coupling in software design?

Measure of how strongly modules depend on each other

What is cohesion in software design?

Measure of how closely related tasks within a module are

In system development, boundary-value testing focuses on what?

Input values at the extremes of allowable ranges

Which topology connects devices through a central hub or switch?

Star topology

Which hashing term describes two keys producing the same address?

Collision

What is an 8-hex-digit notation used for?

IPv6 address format

Which file type stores data in computer-internal (binary) form only meaningful to programs?

Binary file

What ethical principle says an act is ethical if most people agree?

Social contract

What three steps are required to digitize audio for storage?

Sampling, quantization, and coding