CBSE Class 9 Social Science Shaping of the Earth’s Surface (Class 9 NCERT New) Quiz 4

1. An earthquake is.

A The sudden vibration of the Earth’s crust due to the release of energy in the form of seismic waves B The slow bending of rock layers over millions of years C The gradual wearing away of rock surfaces by wind D A seasonal flood on a river’s floodplain

2. A landslide is.

A The rapid downslope movement of rock, soil or debris under the influence of gravity B The slow chemical alteration of bedrock in place C The uplift of land due to tectonic forces D A standing wave in a bay caused by tides

3. GLOF stands for.

A Glacial Lake Outburst Flood B Global Lake Overflow Factor C Ground Level Ozone Formation D Glacier Layer Oscillation Feature

4. Which statement best explains the theory of plate tectonics with a suitable example?

A Earth’s rigid lithosphere is broken into plates that move over the ductile asthenosphere; for example, the Indian Plate colliding with the Eurasian Plate formed the Himalayas B Continents drift but ocean floors are fixed; for example, the Atlantic Ocean has not changed since its formation C Plates only rotate without colliding; for example, the Pacific Plate spins in place D Only volcanic activity moves plates; for example, lava pushes continents across oceans

5. Which sequence correctly describes the Earth’s interior structure from the surface downward?

A Crust → mantle → core B Core → mantle → crust C Mantle → core → crust D Crust → core → mantle

6. Rivers as agents of gradation primarily.

A Erode, transport and deposit sediments to shape valleys, floodplains and deltas B Only deposit sediments along coastlines C Only carve U-shaped valleys by plucking D Create dunes by deflation and abrasion

7. Glaciers as agents of gradation primarily.

A Erode, transport and deposit materials forming U-shaped valleys and moraines B Only weather rocks chemically in situ C Form V-shaped valleys by downcutting D Build beaches and spits along coasts

8. In deserts, wind most commonly.

A Erodes by deflation and abrasion and deposits sand to form dunes and other features B Lifts entire boulders and throws them long distances C Creates tidal currents and marine terraces D Forms glacial cirques on mountain peaks

9. U-shaped valleys are formed mainly by.

A Glacial erosion through plucking and abrasion B River downcutting in youthful stage C Wind deflation on sandy plains D Tectonic uplift along faults

10. Which statement best summarizes landslides?

A Rapid movement of rock and debris down slopes, often triggered by heavy rainfall, earthquakes or human activities B Slow upward creep of soil on gentle slopes due to plant growth C Sinking of land over underground caves due to dissolution D Seasonal overbank flooding on wide floodplains