Explanation

Environmental errors occur due to changes in surrounding conditions like humidity, pressure, temperature, wind, or gravity.

They affect the measurement instruments or the observed system.

Explanation

Mass is a scalar quantity; it has magnitude only and no direction.

Acceleration, momentum, and impulse are all vector quantities with both magnitude and direction.

Explanation

Algae growth is more common in soft water as it lacks high calcium and magnesium content.

Hard water inhibits algae due to high mineral content.

Explanation

Personal errors arise due to inexperience, carelessness, or limitations of the observer.

They are different from instrumental or systematic errors.

Explanation

BTU (British Thermal Unit) is a unit of heat energy.

It is defined as the energy needed to raise 1 pound of water by 1°F.

Explanation

C + O2 → CO2

12 kg C + 32 kg O2 → 44 kg CO2

1 kg C needs (32/12) kg O2 = 2.67 kg O2

Air has ~23% O2 by mass

Air required = 2.67 / 0.23 ≈ 11.6 kg

Explanation

The second law of thermodynamics introduces entropy as a measure of disorder or energy unavailability.

It states that entropy of an isolated system never decreases and governs the direction of natural processes.

Explanation

Extensive properties depend on the amount of matter in the system.

Volume increases with system size, unlike density, pressure, or temperature which are intensive properties.

Explanation

Cavitation occurs when local pressure in a liquid drops below its vapor pressure, forming vapor bubbles.

These bubbles collapse violently, potentially damaging pumps, propellers, or turbines.

Explanation

Pelton wheel is an impulse turbine designed for high-head, low-flow water sources.

It efficiently converts kinetic energy of a high-velocity jet into mechanical energy.