Contemporary India - II

Earthquake waves are basically of two types: body waves and surface waves. Body waves are generated due to the release of energy at the focus and move in all directions traveling through the body of the earth. Hence, the name body waves. The body waves interact with the surface rocks and generate new sets of waves called surface waves. These waves move along the surface.

The velocity of waves changes as they travel through materials with different densities. The denser the material, the higher is the velocity. Their direction also changes as they reflect or refract when coming across materials with different densities.

P-waves move faster and are the first to arrive at the surface. These are also called primary waves. The P-waves are similar to sound waves. They travel through gaseous, liquid and solid materials. S-waves arrive at the surface with some time lag. These are called secondary waves and they can travel only through solid materials. Hence statement 1 is correct.

P-waves vibrate parallel to the direction of the wave. This exerts pressure on the material in the direction of the propagation. As a result, it creates density differences in the material leading to stretching and squeezing of the material. The direction of vibrations of S-waves is perpendicular to the wave direction in the vertical plane. Hence, they create troughs and crests in the material through which they pass.

Surface waves are considered to be the most damaging waves. Hence statement 2 is correct.

Source Citation: NCERT: Class XI Fundamentals of Physical Geography

In India, evergreen forests are found on the eastern and western slopes of the Western Ghats in such states as Tamil Nadu, Karnataka, Kerala and Maharashtra. They are also found in Assam, Arunachal Pradesh, Meghalaya, Nagaland, Tripura, West Bengal and Andaman and Nicobar Islands.

Source: NCERT: Class 11th India Physical Environment

Freshwater is a vital resource for life on Earth. It is primarily found in the following forms:

• Ice caps and glaciers
• Groundwater
• Surface water

Understanding the distribution of freshwater is crucial for:

1. Water management
2. Environmental conservation
3. Climate studies

Most of the Earth's freshwater is trapped in ice caps and glaciers, which significantly limits the amount available for human consumption and ecosystem support.

Source: NCERT: Ecology and Environment

The Godavari River has several principal tributaries, including the Penganga, Indravati, Pranahita, and Manjra. Among the rivers listed in the question, Indravati and Pranahita are tributaries of the Godavari. Therefore, the correct answer is option (d) 2 and 3 only.

Source: NCERT: Class 12 India Physical Environment

Montreal Protocol on Substances that Deplete the Ozone Layer (a protocol to the Vienna Convention for the Protection of the Ozone Layer) is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.

Source: NCERT