PMS 2026 GK Practice Set - 1000 One-Liners, Q151-200 (Earth Science: Earthquakes, Volcanoes, Disasters, Rocks, Minerals & Energy) Solved MCQs

Correct Answer: Sudden movement of tectonic plates

Earthquakes are caused mainly by the sudden movement of tectonic plates, which releases stored energy as seismic waves.

Correct Answer: Mercalli scale

The Mercalli scale measures earthquake intensity, i.e. the observed effects at a place; the Richter scale measures magnitude.

Correct Answer: Tropical storms / Hurricanes

Tropical cyclones are also called hurricanes (Atlantic/Caribbean) and typhoons (north-west Pacific); 'cyclone' is the name used in the Indian Ocean and South Pacific.

Correct Answer: Magma pressure beneath Earth's crust

Volcanoes erupt when pressure from magma beneath the Earth's crust forces molten rock to the surface.

Correct Answer: Broad, gentle slopes

Shield volcanoes are built up by fluid lava flows and have broad, gentle slopes.

Correct Answer: Steep slopes & explosive eruptions

Composite (stratovolcanoes) are steep-sided and erupt explosively, alternating lava flows and ash layers.

Correct Answer: Seismic waves

The waves generated by an earthquake are called seismic waves.

Correct Answer: Primary, fastest seismic waves

P-waves (primary waves) are the fastest seismic waves and travel through solids, liquids and gases.

Correct Answer: Secondary, slower seismic waves

S-waves (secondary waves) are slower than P-waves and travel only through solids.

Correct Answer: Heavy rainfall & slope instability

Landslides are often triggered by heavy rainfall and slope instability, which weaken the ground holding a slope together.

Correct Answer: Excessive rainfall & poor drainage

Flooding is caused by excessive rainfall and poor drainage, when water cannot drain away fast enough.

Correct Answer: Water scarcity

A drought is a prolonged period of abnormally low rainfall leading to water scarcity.

Correct Answer: Formation, breakdown & reformation of rocks

The rock cycle is the continuous process by which rocks form, break down and reform as igneous, sedimentary or metamorphic rock.

Correct Answer: Cooling of molten magma

Igneous rocks form when molten magma cools and solidifies.

Correct Answer: Compaction & cementation of sediments

Sedimentary rocks form by the compaction and cementation of sediments.

Correct Answer: Heat & pressure on existing rocks

Metamorphic rocks form when existing rocks are changed by heat and pressure without melting.

Correct Answer: Igneous rock

Granite is an igneous rock, formed from slowly cooled magma.

Correct Answer: Sedimentary rock

Sandstone is a sedimentary rock made of cemented sand grains.

Correct Answer: Metamorphic rock

Marble is a metamorphic rock formed from limestone under heat and pressure.

Correct Answer: Inorganic solids with definite composition

Minerals are naturally occurring inorganic solids with a definite chemical composition and crystal structure.

Correct Answer: Silicon dioxide (SiO2)

Quartz is a mineral made of silicon dioxide (SiO2).

Correct Answer: Fe2O3 / Hematite

Iron ore is primarily hematite, Fe2O3 (with magnetite, Fe3O4, as the other major ore).

Correct Answer: Aluminum

Bauxite is the main ore of aluminium.

Correct Answer: Fossilized plants

Coal is formed from fossilized plant remains buried and compressed over millions of years.

Correct Answer: Minerals from Earth

Mining is the process of extracting minerals and other geological materials from the Earth.

Correct Answer: Shallow mineral deposits

Surface (open-pit/strip) mining is suitable for shallow mineral deposits near the Earth's surface.

Correct Answer: Deep mineral deposits

Underground mining is used for deep mineral deposits that cannot be reached by surface mining.

Correct Answer: Environmental impact

Renewable energy reduces environmental impact because it produces little or no greenhouse-gas emissions in use.

Correct Answer: Wind turbines

Wind turbines convert the kinetic energy of wind into electricity.

Correct Answer: Earth's internal heat

Geothermal energy is obtained from the Earth's internal heat.

Correct Answer: Take millions of years to form

Fossil fuels are non-renewable because they take millions of years to form, far slower than the rate at which they are used.

Correct Answer: Electricity generation & industry

Coal is primarily used for electricity generation and in industry (e.g. steelmaking).

Correct Answer: Fuel & petrochemicals

Petroleum is used mainly as fuel and as the feedstock for petrochemicals.

Correct Answer: Cooking, electricity & heating

Natural gas is used for cooking, electricity generation and heating.

Correct Answer: Reduce wastage & pollution

Energy conservation aims to reduce energy wastage and the pollution caused by energy use.

Correct Answer: Modern technology & insulation

Energy-use efficiency is increased by modern technology and insulation, which cut the energy lost in use.

Correct Answer: Open, windy areas

Wind farms are mostly built in open, windy areas where wind flow is strong and unobstructed.

Correct Answer: Water storage & irrigation

Hydroelectric dams also provide water storage and irrigation, besides generating electricity.

Correct Answer: Metallic & non-metallic

Minerals are classified as metallic and non-metallic minerals.

Correct Answer: Iron, copper, gold, aluminum

Metallic minerals include iron, copper, gold and aluminium ores.

Correct Answer: Limestone, gypsum, phosphate

Non-metallic minerals include limestone, gypsum and phosphate.