RSSB Computer Instructor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Von Neumann bottleneck

The performance limit caused by transferring instructions and data between the CPU and main memory over a shared bus. Caches and pipelining reduce its effect.

Two's complement range

For an n-bit signed integer the representable range is -2^(n-1) through +2^(n-1)-1. Negation is done by inverting all bits and adding one.

Universal gates

NAND and NOR gates are called universal because any Boolean function can be built using only one of them, including NOT, AND, and OR.

RISC versus CISC

RISC uses a small set of fixed-length instructions and many registers to enable pipelining. CISC uses complex variable-length instructions often implemented with microcode.

Context switch

The operating system saves the state of a running process in its process control block and restores another process's state so it can run.

Deadlock Coffman conditions

Mutual exclusion, hold and wait, no preemption, and circular wait. Deadlock can occur only when all four conditions hold at the same time.

Thrashing

A condition in which a system spends more time paging pages in and out than executing processes, usually because too few frames are allocated per process.

Round-robin scheduling

A preemptive CPU scheduling algorithm that gives each ready process a fixed time quantum in cyclic order, improving response time and preventing starvation.

OSI model layers

Seven layers from bottom to top: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Each layer provides services to the layer above it.

TCP three-way handshake

Connection setup using SYN, then SYN-ACK, then ACK. It synchronizes sequence numbers and confirms that both endpoints are ready to exchange data.

Subnet host count

The number of usable hosts in a subnet equals 2 raised to the number of host bits, minus two, because the network and broadcast addresses cannot be assigned.

DNS and DHCP

DNS maps human-readable domain names to IP addresses. DHCP dynamically assigns IP addresses and related configuration to hosts joining a network.

ACID properties

Atomicity, Consistency, Isolation, and Durability. These properties guarantee that database transactions are processed reliably despite failures and concurrency.

Third normal form

A relation is in 3NF when it is in 2NF and has no transitive dependency, meaning non-key attributes depend only on candidate keys, not on other non-key attributes.

Primary key versus foreign key

A primary key uniquely identifies each row and cannot be null. A foreign key references a candidate key in another table and enforces referential integrity.

SQL GROUP BY and HAVING

GROUP BY forms groups of rows sharing column values. HAVING filters those groups after aggregation, whereas WHERE filters individual rows before grouping.

Binary search complexity

Binary search repeatedly halves a sorted array, so it runs in O(log n) time. It requires random access and a sorted input to work correctly.

Stack versus queue

A stack is last-in-first-out, with push and pop at one end. A queue is first-in-first-out, with insertion at the rear and removal at the front.

Merge sort

A divide-and-conquer sorting algorithm that splits the array, sorts each half recursively, and merges them. It runs in O(n log n) time and needs O(n) extra space.

BFS and DFS

Breadth-first search explores level by level using a queue and finds shortest unweighted paths. Depth-first search explores as deep as possible using a stack or recursion.

Waterfall versus Agile

Waterfall follows sequential phases with requirements fixed early. Agile delivers working increments iteratively, welcoming changing requirements through short cycles.

Black-box and white-box testing

Black-box testing checks behavior against requirements without knowledge of internals. White-box testing exercises internal code paths and measures coverage.

HTTP status code classes

2xx indicates success, 3xx a redirection, 4xx a client error such as a bad request, and 5xx a server error. The first digit identifies the class.

Digital signature

A value created with the sender's private key and verified with the sender's public key. It provides authentication, integrity, and non-repudiation.

Symmetric versus asymmetric encryption

Symmetric encryption uses one shared secret key and is fast. Asymmetric encryption uses a public-private key pair and simplifies key distribution but is slower.

Phishing

A social-engineering attack in which deceptive email, messages, or websites trick users into revealing credentials or installing malware by impersonating a trusted entity.

De Morgan's theorems

The complement of a product equals the sum of the complements, and the complement of a sum equals the product of the complements: (AB)' = A'+B' and (A+B)' = A'B'.

Pipeline data hazard

A situation where an instruction depends on the result of an earlier instruction still in the pipeline. Forwarding or stalling resolves it.

Amdahl's law

Speedup equals 1 divided by (1 minus p) plus p divided by s, where p is the improved fraction and s the improvement factor. It bounds parallel speedup.

Rajasthan hill forts

Six Rajasthan forts are UNESCO World Heritage sites: Chittorgarh, Kumbhalgarh, Ranthambore, Amber, Jaisalmer, and Gagron, recognized for Rajput military architecture.

Hindi समास

समास दो या अधिक शब्दों का संक्षिप्त रूप है। मुख्य भेद तत्पुरुष, कर्मधारय, द्विगु, द्वंद्व और बहुव्रीहि हैं, जिन्हें प्रधान पद से पहचाना जाता है।

Formative assessment

Assessment conducted during instruction to monitor learning and provide feedback. It is low-stakes and guides teaching adjustments rather than assigning final grades.