Explanation

• Radio signals are reflected by the ionosphere
• It lies roughly 60 km to 1000 km above Earth.
• It reflects radio waves back to Earth
• It is very important for AM radio

Last updated by NA on 28April 2026

Explanation

• The Earth’s atmosphere is divided into different layers (Troposphere, Mesosphere, and Exosphere).
• Hydrosphere refers to all water bodies on Earth.
• Therefore, Hydrosphere is not part of the atmosphere.

Additional information:

• Troposphere: 0–12 km (weather layer)
• Stratosphere: 12–50 km
• Mesosphere: 50–85 km
• Thermosphere: 85–600 km
• Exosphere: 600 km and above

Last verified on 21-04-2026

Explanation

• Rainfall is measured using a Rain Gauge.
• It collects rainwater and measures it in millimeters (mm).
• Widely used in weather forecasting and meteorology.
• Helps in studying climate and agriculture patterns.

Last verified on 31-03-2026

Explanation

In a cloudburst, rainfall specifically exceeds 100 millimetres (about 4 inches) per hour over a localized area. 

Explanation

• Limiting factors are environmental conditions that restrict the growth, abundance, or distribution of organisms.
• They determine which species can survive and how many individuals of each species can exist in an ecosystem.
• Limiting factors can be abiotic (non-living) like sunlight, water, or temperature.
• They can also be biotic (living) like competition, predation, or disease.

Last verified on 15-03-2026

Explanation

• Tundra is a cold, treeless region found near the Arctic and Antarctic.
• Soil is often frozen (permafrost) throughout the year.
• Vegetation includes mosses, lichens, and low shrubs.
• Animals adapted: polar bears, arctic foxes, reindeer.

Last verified on 13-03-2026

Explanation

• Chlorofluorocarbons (CFCs) are chemical compounds used in refrigerators, air conditioners, and aerosol sprays.
• When released into the atmosphere, CFCs destroy the ozone layer by breaking down O₃ molecules.
• The ozone layer protects Earth from harmful ultraviolet (UV) radiation.

Last verified on 10-03-2026

Explanation

• The ozone layer acts as Earth’s natural sunscreen, protecting life from the sun’s harmful ultraviolet (UV) radiation.
• UV radiation can cause skin cancer, eye damage, and harm to plants and animals.

Additional information:

• Chemical Formula: O₃ (three oxygen atoms)
• Layer Location: Stratosphere, 15–40 km above Earth
• Function: Absorbs UV-B and UV-C rays from the Sun
• Depletion Causes: Air pollution, CFCs, industrial chemicals
• Protection Measures: Reduce CFC use, ozone-friendly products

Last verified on 09-03-2026

Explanation

Red is the top (outermost) color of the rainbow.

Due to having the longest wavelength of visible light (approx. 620–750 nm)

There are seven colours in a rainbow:

1. Red

2. Orange

3. Yellow

4. Green

5. Blue

6. Indigo

7. Violet

Last updated question 26 feb 2026

Explanation

Greenhouse gases trap heat primarily by absorbing and re-emitting infrared radiation emitted from the Earth's surface

Molecules with three or more atoms, such as CO2 and methane,

Allow them to absorb this longwave radiation and radiate it back towards the surface

Last updated question 25 feb 2026