Read each question, consider the options, then reveal the correct answer and explanation.
100 MCQs10 per page9 of 10
MCQ 81Database Pl/sql
Which of the following best describes the purpose of a 'database catalog' (system catalog or data dictionary)?
A physical printed manual for the database software
A set of internal system tables and views that store metadata about the database itself, such as table structures, indexes, and permissions
A synonym for a user-created table
A technique used only for backups
Correct answerB — A set of internal system tables and views that store metadata about the database itself, such as table structures, indexes, and permissions
Explanation
The database catalog (or system catalog/data dictionary) consists of internal system tables and views maintained by the database engine itself, storing metadata about the database's own structure, such as table definitions, columns, indexes, constraints, and permissions.
MCQ 82Operating Systems
What is the purpose of 'process resource limits' (such as those set via ulimit on Unix-like systems)?
To permanently prevent any process from running
To restrict the amount of specific resources (like open files, memory, or CPU time) a process is allowed to consume, preventing a single process from monopolizing system resources
A synonym for CPU affinity
A feature used only for network sockets
Correct answerB — To restrict the amount of specific resources (like open files, memory, or CPU time) a process is allowed to consume, preventing a single process from monopolizing system resources
Explanation
Resource limits (like those configured via ulimit) restrict how much of specific resources (open file descriptors, memory, CPU time, etc.) a process is permitted to use, helping prevent a single misbehaving or resource-hungry process from destabilizing the entire system.
MCQ 83Computer Hardware & Architecture
Which of the following best describes the purpose of a 'crossbar switch' in interconnect architecture, such as within a multi-core processor or network switch?
A single, shared bus that all components must contend for
A synonym for a ring topology
A component used only for external network cabling
A switching architecture that allows any input to be connected to any output simultaneously through a grid of switches, minimizing contention compared to a shared bus
Correct answerD — A switching architecture that allows any input to be connected to any output simultaneously through a grid of switches, minimizing contention compared to a shared bus
Explanation
A crossbar switch uses a grid of switches that allows any input to be directly connected to any output, enabling multiple simultaneous connections without the contention bottleneck of a single shared bus, though at a higher hardware complexity cost as scale increases.
MCQ 84Windows Linux File Systems
Which of the following best describes the purpose of Linux 'namespaces' (a distinct kernel feature from cgroups) in the context of containerization?
A feature for compressing files
A synonym for a shell alias
A feature used only for managing user passwords
A kernel feature that isolates and virtualizes system resources (like process IDs, network interfaces, and mount points) so a group of processes sees its own isolated view of the system
Correct answerD — A kernel feature that isolates and virtualizes system resources (like process IDs, network interfaces, and mount points) so a group of processes sees its own isolated view of the system
Explanation
Linux namespaces isolate and virtualize various system resources (such as process IDs, network interfaces, or mount points), giving a group of processes their own isolated view of these resources, forming a key building block of container technology alongside cgroups.
MCQ 85Web Technologies
What is the purpose of PHP's 'weak references' (WeakMap and WeakReference, introduced in PHP 7.4/8.0)?
To permanently prevent garbage collection of an object
To hold a reference to an object without preventing it from being garbage collected once no other strong references remain, useful for caches or metadata that shouldn't keep objects alive artificially
A synonym for a regular object property
A feature used only for arrays
Correct answerB — To hold a reference to an object without preventing it from being garbage collected once no other strong references remain, useful for caches or metadata that shouldn't keep objects alive artificially
Explanation
Weak references allow code to reference an object without preventing the garbage collector from reclaiming it once no strong references remain elsewhere, which is useful for building caches or attaching metadata that shouldn't artificially extend an object's lifetime.
MCQ 86Oop & Uml
What is 'duck typing', a concept associated with dynamically-typed object-oriented languages?
A strict requirement that objects must explicitly implement a named interface
A style where an object's suitability is determined by the presence of certain methods or properties, rather than its explicit type or class
A synonym for static typing
A design pattern used only for animal simulation programs
Correct answerB — A style where an object's suitability is determined by the presence of certain methods or properties, rather than its explicit type or class
Explanation
Duck typing ('if it walks like a duck and quacks like a duck, it's a duck') determines an object's suitability for an operation based on whether it has the necessary methods or properties, rather than requiring an explicit type declaration or interface implementation.
MCQ 87Computer Networks
What is the purpose of 'BGP communities' 'no-export' and 'no-advertise' well-known values?
To permanently delete a route
To signal specific route propagation restrictions, such as preventing a route from being advertised beyond the local autonomous system or to any external peer at all
A synonym for route aggregation
A technique used only for internal DNS
Correct answerB — To signal specific route propagation restrictions, such as preventing a route from being advertised beyond the local autonomous system or to any external peer at all
Explanation
Well-known BGP communities like no-export and no-advertise provide standardized signals for restricting how far a route should be propagated, such as preventing it from being sent to external BGP peers, without requiring custom filtering configuration on every router.
MCQ 88Database Pl/sql
Which of the following best describes the purpose of a 'database schema versioning' strategy in continuous deployment pipelines?
To permanently lock a schema to a single version forever
To track and apply incremental, ordered schema changes in a controlled, repeatable way across environments, ensuring the database structure stays synchronized with application code changes
A synonym for a full database backup
A technique used only for NoSQL databases
Correct answerB — To track and apply incremental, ordered schema changes in a controlled, repeatable way across environments, ensuring the database structure stays synchronized with application code changes
Explanation
Schema versioning tracks incremental, ordered database structure changes, ensuring they can be applied consistently and repeatably across development, staging, and production environments, keeping the database synchronized with corresponding application code changes.
MCQ 89Operating Systems
What is the purpose of 'RCU' (Read-Copy-Update) as a synchronization mechanism used in the Linux kernel?
To require exclusive locking for every read operation
A synonym for a standard mutex
A mechanism used only for network packet processing
To allow readers to access shared data concurrently without locking, while writers create a new copy of the data and atomically update the reference, avoiding blocking readers
Correct answerD — To allow readers to access shared data concurrently without locking, while writers create a new copy of the data and atomically update the reference, avoiding blocking readers
Explanation
RCU allows readers to access shared data without any locking overhead at all, while writers make their changes on a new copy of the data and atomically swap the pointer/reference, allowing existing readers to safely finish using the old version without being blocked.
MCQ 90System Analysis And Design
What is the purpose of 'earned value management' (EVM) as a project performance measurement technique?
To calculate an employee's salary
A synonym for a use case diagram
A technique used only for marketing budgets
To integrate measurements of project scope, schedule, and cost to objectively assess project performance and progress against the original plan
Correct answerD — To integrate measurements of project scope, schedule, and cost to objectively assess project performance and progress against the original plan
Explanation
Earned Value Management integrates measurements of scope, schedule, and cost into a unified framework, allowing project managers to objectively assess whether a project is ahead of or behind schedule, and under or over budget, relative to the original baseline plan.
