Bhutan Civil Service Main Examination (ICT Category) flashcards

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

Instruction cycle

The sequence a CPU repeats: fetch the instruction from memory, decode it, execute the operation, and store the result, then increment the program counter.

Thrashing

A condition where the system spends most of its time swapping pages instead of executing processes, caused by too many processes competing for too few physical memory frames.

Deadlock conditions

Four conditions must all hold for deadlock: mutual exclusion, hold-and-wait, no preemption, and circular wait. Removing any single condition prevents deadlock entirely.

Binary search complexity

Searching a sorted array by repeatedly halving the interval, giving O(log n) comparisons. It requires random access and a correctly sorted input to work.

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 enqueue at the rear and dequeue at the front.

Hash collision resolution

When two keys map to the same bucket, chaining stores a list per bucket while open addressing probes other slots. Average lookup stays O(1) under a low load factor.

Third normal form

A relation is in 3NF when it is in 2NF and has no transitive dependency, meaning every non-key attribute depends only on candidate keys and nothing else.

ACID properties

Atomicity makes transactions all-or-nothing, consistency preserves constraints, isolation hides concurrent effects, and durability keeps committed data after a crash.

Foreign key

An attribute in one table that references the primary or unique key of another table, enforcing referential integrity so orphan records cannot exist.

TCP versus UDP

TCP is connection-oriented and reliable with ordered delivery and congestion control; UDP is connectionless and unreliable but has lower overhead and latency.

Subnet usable hosts

For a subnet with h host bits, usable host addresses equal 2^h minus 2, since the all-zeros network address and all-ones broadcast address are reserved.

DNS record types

A maps a name to an IPv4 address, AAAA to IPv6, MX to a mail server, CNAME to an alias, and PTR to a reverse lookup address.

DHCP DORA

The four-step address assignment exchange: Discover broadcast by the client, Offer from a server, Request from the client, and Acknowledge from the server.

Coupling and cohesion

Coupling measures dependency between modules and should be low; cohesion measures relatedness within a module and should be high, giving maintainable designs.

Verification versus validation

Verification checks that the product is built correctly according to its specification; validation checks that the correct product was built to meet user needs.

Boundary value analysis

A black-box test technique that selects inputs at and just around the edges of valid ranges, where defects cluster, rather than choosing arbitrary middle values.

Asymmetric encryption

A cryptographic scheme using a public key to encrypt and a matching private key to decrypt, solving key distribution but running much slower than symmetric ciphers.

Digital signature

A hash of a message encrypted with the sender's private key. Anyone can verify it with the public key, proving integrity, authenticity, and non-repudiation.

SQL injection

An attack where untrusted input is concatenated into a database query, altering its logic. Parameterized queries and input validation are the standard defenses.

HTTP status classes

The first digit groups responses: 2xx success, 3xx redirection, 4xx client error such as 404, and 5xx server error such as 500.

REST statelessness

Each REST request carries all information needed to process it, so the server keeps no client session state between calls, improving scalability and reliability.

Same-origin policy

A browser rule blocking scripts from one origin from reading responses of another origin, unless the target server explicitly allows it through CORS headers.

Overfitting

A model fits training data well but generalizes poorly to new data, shown by low training error and high validation error. More data and regularization help.

Precision and recall

Precision is true positives divided by predicted positives; recall is true positives divided by actual positives. F1 is their harmonic mean.

Cloud service models

IaaS provides virtual machines and storage, PaaS provides a managed runtime, and SaaS provides a finished application, with provider responsibility increasing in that order.

CAP theorem

A distributed data store can guarantee only two of consistency, availability, and partition tolerance at once; network partitions force a choice between the first two.

Digital Drukyul

Bhutan's flagship digital transformation initiative, covering national digital identity, e-government services, and expansion of ICT infrastructure across the country.

BICMA

The Bhutan InfoComm and Media Authority, the regulator overseeing telecommunications, broadcasting, and media content under the Information, Communications and Media Act.

Electronic Transactions Act

Bhutanese legislation, enacted in 2003 and amended in 2010, that grants legal recognition to electronic records, electronic contracts, and digital signatures.

Compound interest formula

Amount equals principal times one plus the rate divided by 100, raised to the number of periods; interest is the amount minus the original principal.

National Council composition

Bhutan's upper house has 25 members: 20 elected from the dzongkhags and 5 eminent persons appointed by the King, serving five-year terms.

Gross National Happiness

Bhutan's development philosophy, measured across nine domains including living standards, health, education, culture, and ecological diversity, guiding national policy.