Tag: science & technology

Helium is the second most abundant element in the Sun, accounting for approximately 24% of the Sun's mass (about 8% by number of atoms). While hydrogen makes up 74% by mass, helium produced through nuclear fusion in the Sun's core gradually accumulates. The remaining 2% consists of heavier elements including oxygen, carbon, neon, and iron, which were present in the molecular cloud from which the Sun formed.

The Sun's diameter is approximately 109 times that of Earth. The Sun has a diameter of about 1.39 million kilometers (864,000 miles), while Earth's diameter is about 12,742 kilometers (7,918 miles). This means approximately 109 Earths could be lined up across the face of the Sun. The Sun is so large that about 1.3 million Earths could fit inside it by volume.

The Sun is approximately 4.5 billion years old, having formed from the gravitational collapse of a region within a large molecular cloud about 4.6 billion years ago. This age estimate is based on radioactive dating of meteorites and analysis of the Sun's composition and evolution models. The Sun is currently in the main sequence phase of its lifecycle and is expected to remain stable for another 5 billion years before expanding into a red giant.

Idea Cellular is indeed owned by the Aditya Birla Group. Escotel was acquired by Idea, Aircel was a different company (now merged with Airtel), and Tata Teleservices is part of the Tata Group.

Yuri Gagarin was the first human to travel to space on April 12, 1961, aboard Vostok 1. Neil Armstrong was the first person to walk on the Moon (1969), not the first in space. Edwin 'Buzz' Aldrin was the second person to walk on the Moon. Kalpana Chawla was a NASA astronaut who flew on Space Shuttle missions much later (1997, 2003).

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).