Science and Technology Fundamentals

The three main categories of galaxies in the Hubble classification system are Spiral, Elliptical, and Irregular. Spiral galaxies have rotating disk arms (like the Milky Way), Elliptical galaxies are shaped like ellipsoids with little structure, and Irregular galaxies lack a distinct shape. The term 'unshaped' in options B and C is not a standard astronomical term for galaxy classification.

A nebula is indeed called the 'nursery for the formation of stars' because it contains gas and dust that can collapse under gravity to form new stars. Galaxies contain many stars but aren't formation sites, clouds alone lack the necessary composition, and black holes consume matter rather than create stars.

According to modern cosmological models, the universe is approximately 68% dark energy, 27% dark matter, and 5% visible/ordinary matter. Option B (75%, 20%, 5%) is the closest approximation among the choices, though not exact. Dark energy drives accelerated expansion, dark matter provides gravitational structure, and visible matter makes up stars, planets, and us.

REST stands for Representational State Transfer. It's an architectural style for distributed systems that uses standard HTTP methods like GET, POST, PUT, DELETE. The key idea is that resources are represented and transferred between client and server in various formats (JSON, XML, HTML).

All the listed options (Reusability, Granularity, and Interoperability) ARE key characteristics of Service Oriented Architecture. Therefore, the correct answer is 'None of these' because the question asks which is NOT a characteristic. SOA emphasizes reusable services, appropriate granularity, and interoperability between different platforms.

Security is typically cited as a CONCERN or challenge in cloud computing, not as an advantage. The main advantages include: increased utilization of computing resources (elasticity), immediate access to wide variety of services, and low management costs. While cloud providers offer security features, security concerns (data privacy, compliance, shared resources) remain a key challenge for cloud adoption.

Chrome OS is indeed a Linux kernel-based operating system designed by Google. Web Services Description Language (WSDL) is an XML-based language for describing web services. Both statements are factually correct, making option C the right choice.

Britannica Online represents the Web 1.0 model of expert-created, read-only content. Wikipedia embodies Web 2.0 principles with user-generated content and collaborative editing. The parallel shows the evolution from centralized to participatory web models.

Service Oriented Architecture (SOA) is designed to be technology-agnostic and platform-independent. Services communicate through standardized interfaces and protocols, allowing systems built with different technologies on different platforms to interoperate seamlessly.

DoubleClick (Web 1.0 advertising) matches with Google AdSense (Web 2.0 contextual advertising). Page views (Web 1.0 metric) relates to BitTorrent (Web 2.0 distributed file sharing shifting focus to bandwidth). Akamai (Web 1.0 CDN) maps to cost per click (Web 2.0 performance-based advertising model).

Cloud computing follows a pay-as-you-go model that converts capital expenditure (CapEx) into operational expenditure (OpEx). Organizations avoid large upfront hardware/software investments, paying only for resources used. Options B, C, and D are genuine cloud risks: data resides on provider infrastructure, services can experience outages, and data residency must meet regulatory requirements.

COBRA (Common Object Request Broker Architecture) is a standard developed by the Object Management Group (OMG) for distributed object communication. It enables objects to communicate across different platforms and programming languages. The correct expansion is Common Object Request Broker Architecture.

Geostationary satellites must orbit at approximately 35,786 km above Earth's surface. This altitude allows the satellite to orbit at the same rate as Earth's rotation, appearing stationary from the ground. 36,000 km is the closest option to this value.

This is an exact duplicate of question 53985. Geostationary satellites must orbit at approximately 35,786 km above Earth's surface. This altitude allows the satellite to orbit at the same rate as Earth's rotation, appearing stationary from the ground. 36,000 km is the closest option to this value.

Boeing is the correct answer - it's the largest airplane manufacturer in North America and one of the two major aircraft manufacturers globally (alongside Airbus). Boeing is headquartered in Chicago, USA and produces commercial and military aircraft. Airbus is European, Rolls Royce is primarily an engine manufacturer, and BAE Systems is British.

Engine is the correct answer - aircraft engines (jet engines or propellers) generate thrust by pushing air backward, which propels the airplane forward according to Newton's third law. The fuselage is the main body, the tail contains control surfaces, and stabilizers provide stability but none produce thrust like engines do.

Four is the correct answer - the Boeing 747 is famously known as the 'Queen of the Skies' and has four engines mounted on its wings. This configuration was necessary for the heavy jumbo jet's payload and range requirements when first designed. Modern aircraft like the 777 use only two engines due to technological advances.

Wings & Tail is the correct answer - aircraft steering is achieved through a combination of control surfaces: ailerons on the wings control roll, while the rudder on the vertical stabilizer (tail) controls yaw. The elevators on the horizontal tail stabilizer control pitch. Together, these surfaces allow pilots to steer the aircraft in all three dimensions. Engines provide thrust but don't steer.