Explanation

• Brass gets discoloured in air due to Hydrogen Sulphide (H₂S).
• This gas reacts with the copper in brass to form a dark layer of copper sulphide, giving it a tarnished appearance.

Additional information:

• Tarnishing is superficial and can be cleaned using polishing or chemical cleaners.
• This phenomenon is also called sulphide tarnishing.

Last verified on 17-01-2026

Explanation

Fruits generally have the maximum water content.

Additional information:

• Fruits: 80–95% water (e.g., watermelon 92%, orange 87%)
• Vegetables: 70–95% water (e.g., cucumber 96%, spinach 91%)
• Sauces: ~50–80% water depending on type
• Purpose: Hydration and nutrient supply

Last verified on 17-01-2026

Explanation

• Pasteurization of milk is a process of heating milk to kill harmful microorganisms.
• The effectiveness of pasteurization depends on both temperature and time.

Additional information:

• Ultra-high temperature (UHT) treatment: 135–140°C for 2–5 sec for long shelf life.

Last verified on 17-01-2026

Explanation

• The rate at which temperature decreases with increasing altitude is called the Lapse Rate.
• Lapse rate helps predict weather patterns, cloud formation, and stability of the atmosphere.

Additional information:

• Dry Lapse Rate: ~9.8°C/km (unsaturated air)
• Moist Lapse Rate: ~5–6°C/km (saturated air with condensation)

Last verified on 17-01-2026

Explanation

• Cyclone is a system in which winds blow in a spiral form around a low-pressure area.
• Air moves inward and upward due to low atmospheric pressure.
• Cyclones can cause heavy rain, strong winds, and storms.

Last verified on 17-01-2026

Explanation

The Pangolin is widely considered the most illegally trafficked mammal in the world

As 20% of all illegal wildlife trade.

Explanation

Explanation

Seawater is denser than freshwater due to its salt content.

According to Archimedes' principle, a floating object displaces a weight of fluid equal to its own weight.

The denser the fluid, the less volume is needed to equal the ship's weight.

This results in the ship floating higher in the water, decreasing its draft. 

Explanation

Explanation

The yeast used in baking bread is a single-celled fungus,

Specifically, a strain of Saccharomyces cerevisiae, 

It's a living microorganism that ferments sugars in dough, producing gases that cause bread to expand.