DAILY CURRENT AFFAIRS QUIZ – 31 October 2024

Answer C

Igneous Rocks or Primary Rocks

1. Formation of the First Rocks:
   • The first rocks on Earth were formed through the solidification of magma.
2. Definition of Igneous or Primary Rocks:
   • Rocks formed from the solidification of magma (molten rock below the surface) and lava (molten rock above the surface) are known as igneous or primary rocks.
3. Unfossiliferous Nature:
   • Igneous rocks have their origin under conditions of high temperatures, and as a result, they are unfossiliferous.
4. Examples of Igneous Rocks:
   • Some examples of igneous rocks include granite, gabbro, and basalt.
5. Types of Igneous Rocks Based on Cooling:
   • There are three types of igneous rocks based on the cooling of the molten matter: plutonic rocks, volcanic rocks, and intermediate rocks.
6. Types of Igneous Rocks Based on Acid-Forming Radical:
   • Igneous rocks are also categorized into acidic rocks and basic rocks based on the presence of acid-forming radical, silicon.
7. Intrusive Igneous Rocks (Plutonic Rocks):
   • If magma cools slowly at great depths, it results in the formation of intrusive rocks or plutonic rocks.
   • These rocks often have very large mineral grains.
   • Example: Granite.
   • These rocks become visible on the surface only after they have been uplifted and exposed through denudation.
8. Extrusive Igneous Rocks (Lava or Volcanic Rocks):
   • Rapid cooling of magma just below the surface or lava above the surface leads to the formation of extrusive rocks or volcanic rocks.
   • These rocks typically have small and smooth grains due to the rapid cooling process, preventing crystallization.
   • Example: Basalt.
   • The Deccan traps in the Indian peninsular region are of basaltic origin.
9. Basic Rocks:
   • Basic rocks contain a higher proportion of basic oxides, such as iron, aluminum, or magnesium.
   • As a result, they are denser and darker in color.

Ans. a

Explanation:

Newton’s First Law of Motion: An Introduction

Historical Context:

• Sir Isaac Newton unveiled three fundamental laws of motion during the 17th century.
• This article delves into Newton’s first law, providing insights into its key concepts.

Overview of Newton’s 1st Law:

• Newton’s first law serves as an introduction to the motion of objects and the forces influencing them.
• Specifically, it addresses the relationship between an object’s motion and the forces acting upon it.

Statement of Newton’s 1st Law:

• According to Newton’s first law, a body remains at rest or continues moving uniformly in a straight line unless an external force is applied.
• In simpler terms, an object won’t initiate motion unless an external force acts upon it. Once in motion, it persists unless another force intervenes.

Alternate Name: Law of Inertia:

• Newton’s first law is commonly referred to as the law of inertia, highlighting the tendency of objects to maintain their state of motion.

Understanding External Forces:

• External forces are alterations in the mechanical energy of an object, encompassing kinetic and potential energy changes.
• These forces originate from external agents and include examples such as friction, normal force, and air resistance.

Answer B (2^ND STATEMENT IS INCORRECT)

Metamorphic Rocks

• The word metamorphic means ‘change of form’.
• Metamorphism is a process by which recrystallisation and reorganisationof minerals occur within a rock. This occurs due to pressure, volume and temperature changes.
• When rocks are forced down to lower levels by tectonic processes or when molten magma rising through the crust comes in contact with the crustal rocks, metamorphosis occurs.
• In the process of metamorphism in some rocks grains or minerals get arranged in layers or lines. Such an arrangement is called foliation or lineation.
• Sometimes minerals or materials of different groups are arranged into alternating thin to thick layers. Such a structure in is called banding.
• Gneissoid, slate, schist, marble, quartzite are some examples of metamorphic rocks.

Causes of Metamorphism

• Orogenic (Mountain Building) Movements:Such movements often take place with an interplay of folding, warping and high temperatures. These processes give existing rocks a new appearance.
• Lava Inflow:The molten magmatic material inside the earth’s crust brings the surrounding rocks under the influence of intense temperature pressure and causes changes in them.
• Geodynamic Forces:The omnipresent geodynamic forces such as plate tectonics also play an important role in metamorphism.

Answer C

Features of the Peninsular Plateau

• Roughly triangular in shape with its base coinciding with the southern edge of the great plain of North India. Apex of the triangular plateau is at Kanniyakumari.
• It covers a total area of about 16 lakh sq km(India as a whole is 32 lakh sq km).
• The average height of the plateau is 600-900 mabove sea level (varies from region to region).
• Most of the peninsular rivers flow west to east indicating it’s general slope.
• Narmada-Tapti are the exceptions which flow from east to west in a rift (rift is caused by divergent boundary (Go back to Interaction of plates).
• The Peninsular Plateau is a one of the oldest landforms of earth.
• It is a highly stable block composed mostly of the Archaean gneisses and schists{Rock System}.
• It has been a stable shield which has gone through little structural changes since its formation.
• Since few hundred million years, Peninsular block has been a land area and has never been submerged beneath the sea except in a few places.
• Peninsular Plateau is an aggregation of several smaller plateaus, hill ranges interspersed with river basins and valleys.

Answer C

Malwa Plateau

• The Malwa Plateau roughly forms a triangle based on the Vindhyan Hills, bounded by the Aravali Range in the west and Madhya Bharat Pathar to the north and Bundelkhand to the east.
• This plateau has two systems of drainage; one towards the Arabian sea (The Narmada, the Tapiand the Mahi), and the other towards the Bay of Bengal (Chambal and Betwa, joining the Yamuna).
• In the north it is drained by the Chambal and many of its right bank tributaries like the Kali, the Sindh and the Parbati. It also includes the upper courses of the Sindh, the Ken and the Betwa.
• It is composed of extensive lava flow and is covered with black soils.
• The general slope is towards the north [decreases from 600 m in the south to less than 500 m in the north]
• This is a rolling plateau dissected by rivers. In the north, the plateau is marked by the Chambal ravines.