Explanation:
An anemometer is used to measure wind speed. Among the given options, wind force is the closest option.

Explanation:
Kinetic energy is K = 1/2 mv². For equal masses, the ratio of kinetic energies equals the ratio of the squares of velocities. Therefore, v₁:v₂ = √4:√9 = 2:3.

Explanation:
Himalayan nettle (Girardinia diversifolia) is a natural source of textile fibre and is used for making textiles and other fibre-based products.

Explanation:
When the amount of a substance is increased, its mass and volume may change, but its density remains unchanged under the same conditions. Density is an intensive property.

Explanation:
Benzene, carbon tetrachloride and trichloroethylene have historically been used as dry-cleaning solvents. Sodium carbonate is not a dry-cleaning solvent.

Explanation:
The Raman effect is observed when light passes through a transparent medium and a part of the light undergoes scattering with a change in frequency.

Explanation:
CNG (Compressed Natural Gas) mainly consists of methane (CH₄), along with small amounts of other hydrocarbons.

Explanation:
Potassium bromide has been used as a sedative. It produces a calming effect on the central nervous system.

Explanation:
Ammonium sulphate is one of the fertilizers that produces high acidity in soil. Its continuous application can increase soil acidity.

Explanation:
NPK is a mixed fertilizer containing the major plant nutrients nitrogen, phosphorus and potassium.