Draw a ray diagram to show the image formed by a convex lens when the object is placed between F and 2F.

Define one calorie.

What is the minimum distance needed for an echo?

Write the name of the electromagnetic radiation which is emitted during a natural radioactivity.

State two conditions necessary for rusting of iron.

What is Electroplating?

What is aqueous and non-aqueous solution? Give an example.

5 g of copper sulphate are dissolved in 100 g of water to form a saturated solution at 298K. Find out the solubility of the solute at the temperature.

Write the chemical equations for the following and identify the type of chemical reactions
i) Burning of magnesium in air
ii) Electric current is passed aqueous solution of sodium chloride
iii) Ammonium hydroxide reacts with nitric acid

A, B and C are three elements which undergo chemical reactions according to following equations.
A₂O₃ + 2B ⟶ B₂O₃ + 2A
3CSO₄ + 2B ⟶ B₂(SO₄)₃ + 3C
3CO + 2A ⟶ A₂O₃ + 3C
Answer the following questions:
(a) Which element is the most reactive?
(b) Which element is the least reactive?

What do you mean by decarboxylation?

A to F are the structural formulae of some organic compounds:

(i) Give the letters which represent the same family.
(ii) Give the letters which do not represent hydrocarbons.
(iii) Flow can 'C' be converted into A?

What is the common step in aerobic and anaerobic pathway?

Name the tissue systems as classified by Sachs.

Draw the ultrastructure of mitochondria and label the parts.

What organs are attached to the two bronchi?

Write the components of the blood.

Though human are heterogeneous in external dimension and colour. The colour of blood is identical. Give reason. 

Explain Gynoecium with a neat labelled diagram.

What is Paleobotany?

Mention two characteristics of stem cells.

What is cancer.

What is Van Mahotsav?

Mention two provisions of the wild life protection Act.

Mention one disadvantage of using Nuclear power.