Explanation

• Corrugated steel roofs reflect most of the Sun’s heat.
• This reduces the amount of heat entering the house.
• Helps keep homes cool in hot climates.
• The shiny/metal surface is good at reflecting radiation.
• Useful in tropical and desert regions.

Last verified on 02-05-2026

Explanation

• Water stored at height has Potential Energy.
• This energy is due to its position (height) above ground.
• When water flows down, it converts into kinetic energy.
• Common example: dams and waterfalls.

Last verified on 02-05-2026

Explanation

• Astigmatism is a vision defect caused by irregular curvature of the cornea or lens.
• It leads to blurred or distorted vision.
• Corrected using cylindrical lenses that adjust light focus properly.
• These lenses focus light in one direction to fix uneven curvature.
• Common in people of all ages.

Last verified on 02-05-2026

Explanation

• Active Remote Sensing sensors emit their own energy and then record the reflection.
• RADAR is a classic active sensor.
• It works using radio waves, even in darkness or cloudy weather.

Active vs Passive Sensors:

• LiDAR (Active)
• Multiband Scanner (Passive)
• Multiframe Camera (Passive)
• Ordinary Camera (Passive)

Last verified on 02-05-2026

Explanation

• A hydrogen bomb works on the principle of nuclear fusion.
• In this process, light atoms (like hydrogen isotopes) combine.
• This fusion releases extremely large energy.
• It is more powerful than an atomic bomb (which uses fission).
• Therefore, it involves complete fusion of atoms.

Last verified on 30-04-2026