If we add a handful of garden soil to a beaker filled three-quarters with water, stir the contents with a stick to dissolve the soil and then let it stand undisturbed for some time, we observe different layers. The order of these layers from the bottom to the top is

• gravel, clay, sand, humus, water

• sand, gravel, clay, water, humus

• clay, sand, gravel, humus, water

• gravel, sand, clay, water, humus

Cereals such as wheat and gram are grown in an area. The soil of this area must be

• loamy and sandy

• clayey

• sandy and clayey

• clayey and loamy

When a copper plate is exposed to moist air for long, it acquires a dull green coating. The green material is

• copper sulphate

• a mixture of copper hydroxide and copper sulphate

• a mixture of copper carbonate and copper sulphate

• a mixture of copper carbonate and copper hydroxide

14.

In which of the following units is the calorific value of fuels generally expressed?

• Calories per gram

• Kilocalories per kilogram

• Joules

• Kilojoules per kilogram

The metamorphosis of tadpoles is not possible if the water in which they are growing does not contain sufficient

• calcium

• oxygen

• iodine

• minerals

Which of the following commonly used fuels has maximum calorific value?

• Compressed Natural Gas (CNG)

• Diesel

• Liquefied Petroleum Gas (LPG)

• Petrol

Air is a mixture of many gases. The percentage by volume, of the gases other than nitrogen and oxygen, i.e., CO₂ methane, argon, ozone and water vapour combined together is about

• 0.1%

• 1%

• 21%

• 78%

Which of the following endocrine glands secretes sugar controlling hormone?

• Adrenal

• Pancreas

• Pituitary

• Thyroid

Select the one which is different from the others in the manner it is applied.

• Electrostatic force

• Frictional force

• Gravitational force

• Magnetic force

A person is suffering from a disease named 'Goitre'. Which of the following glands of the person is not functioning properly?

• Adrenal

• Pancreas

• Pituitary

• Thyroid