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Accumulation of nutrients in lakes and water bodies is called
A) Greenhouse effect B) Eutrophication
C) Humification D) Toxification

Permanent hardness of water is due to

A) Chloride, bicarbonate and sulphate of Ca and Mg
B) Chloride, nitrite and sulphate of Ca and Mg

C) Chloride, sulphate and nitrate of Ca and Mg

D) Chloride, carbonate and nitrate of Ca and Mg

Ozone layer can be found

A) 10-30 kms above earth surface B) 50-100 kms above earth surface
C) At Lithosphere D) At Troposphere

Acidity of rain is best described by presence of

A) Ammonium compounds B) S and N compounds

C) S,N and ammonium compounds D) S or N compounds

To protect ozone layer and to retain properties of CFC, the latter is largely replaced by

A) Methyl chloride B) Hydrofluorocarbon

C) Fluoromethane D) Methane

The main species causing photochemical smog is

A) Oxygen radical B) NO radical

C) Ozone D) Hydroxide radical

Most radioactive element is

A) Thorium B) Uranium C) Plutonium D) Radium
Pyrethrin is a natural

A) Pesticide B) Herbicide C) Fungicide D) Insecticide
Oxidation using potassium dichromate is for determining

A) BOD B) COD

C) Radioactive pollution D) Toxicity

Which of the following corresponds to a linear operator ?
A) Av=¥* B) Av=d¥/dx = 0) A¥=1/¥ 0) ^= ¢

Consider an electron in a 1d box of length 12 A. What will be the energy difference
between E6 and E5 levels (in ണ്‌) for the electron ?
A) 2.86 B) 0.26 C) 2.3 x104 D) 2.3x 10°