From the Window Class 4 NCERT Guide: Concepts, Notes & Solutions

The Changing Landscape: Omana's Journey from Goa to Kerala

As Omana's train moves forward, she notices dramatic changes in the landscape. When she woke up in the morning, the train was passing through Goa. She saw beautiful green fields with red soil and hills covered with trees. This is very different from the dry, brown plains of Gujarat she saw earlier! The change in landscape happens because India has different geographic regions. As you travel south, the climate becomes wetter, leading to lush green vegetation. Omana also notices different kinds of trees, like coconut palms, which are very common in coastal regions like Kerala. Looking out of a train window is not just fun; it is a live geography lesson showing how soil, water availability, and weather shape our natural surroundings.

How Trains Cross Obstacles: Bridges, Tunnels and Level Crossings

1. Crossing Rivers over Bridges — When a train needs to cross a wide river, engineers build a bridge. Bridges are strong structures made of cement, iron, and stone pillars. Omana felt scared when her train crossed a long bridge over a river because she could see the water below and hear the rattling sound of the wheels. Bridges often have parallel roads next to them for cars, buses, and bicycles.
2. Passing Through Tunnels in Mountains — When high mountains block the railway track, instead of going all the way over them, engineers blast a path straight through the mountain to make a tunnel. Tunnels are dark, covered pathways cut through solid rock. Inside a tunnel, the train's lights are turned on, and it feels like night time for a few minutes.
3. Waiting at Level Crossings — A level crossing is where a railway track crosses a road. When a train is coming, the gates are closed so that cars, cycles, and buses stop safely. People must wait patiently behind the closed gates and never try to crawl under them, as it is extremely dangerous.

Cultural Diversity Across Indian States

Safety Rules at Level Crossings

In exams, questions are frequently asked about level crossing safety. Keep these key rules in mind:

1. Never crawl under the gates when they are closed. This is extremely dangerous and illegal.
2. Switch off vehicle engines while waiting. This reduces air and noise pollution, saving fuel.
3. Do not rush when the gates open. Wait for others to clear the path safely before moving forward.

Practice Questions with Solutions

• Q: Why did Omana see a lot of greenery outside after leaving Goa?
  A: Step 1: Analyze the geography of Goa and the surrounding coastal regions. Goa lies in the coastal plains where there is abundant rainfall.
  Step 2: Connect the water availability to vegetation. The wet climate and rich red soil help a variety of trees and crops to grow.
  Final answer: Omana saw a lot of greenery because Goa has rich red soil, high rainfall, and a wet climate which supports the growth of lush green fields, hills covered with trees, and coconut palms.

• Q: What is the difference between a bridge and a tunnel?
  A: Step 1: Define a bridge. A bridge is built over a water body (like a river) or a valley to connect two landmasses.
  Step 2: Define a tunnel. A tunnel is an underground or through-mountain passage dug through rocks for trains or vehicles.
  Final answer: A bridge is constructed over an obstacle like a river to let trains pass, whereas a tunnel is dug through an obstacle like a mountain.

• Q: Why did Omana's train make a different, loud sound when crossing the river?
  A: Step 1: Observe what happens when a train moves on land versus on a bridge. On land, the sound is absorbed by the ground.
  Step 2: Understand the structure of a bridge. Bridges are hollow beneath and made of iron girders.
  Final answer: The train made a loud, rattling sound because it was crossing a bridge with no ground underneath, only water. The sound of the wheels rattled against the metal track and echoed over the water.

• Q: Why should we switch off our vehicle engines at level crossings?
  A: Step 1: Identify the issues when many vehicles keep their engines running while waiting. It leads to smoke and loud noise.
  Step 2: Explain the benefits of turning off engines. It helps in conserving fuel and protecting the environment.
  Final answer: We must switch off vehicle engines to reduce air pollution (smoke) and noise pollution, and to save precious fuel like petrol and diesel.

Frequently Asked Questions